NBSIR 80-211

Review and Refinemen- ATC 3-06 Tentative Seismic Provisions

\Joi nt QomrrHttee^ bn Review arid: Refinement

Coordinating Committee

Committee 1: Seismic Risk Maps

Committee 2: Structural Design

Committee 3: Foundations

Committee 4: Concrete

Committee 5: Masonry

Committee 6: Steel

Committee 7: Wood - Committee 8: Architectural. Mechanical and

Electrical

Committee 9: Regulatory Use

Report of

Joint Committee on Review and Refinement

This report documents the deliberations of a group of professionals jointly

selected by the Building Seismic Safety Council and the National Bureau

of Standards and is 'or use in modifying the Tentative Provisions for trial d|ss:gns.

U.S. Department of Commerce

National Bureau of Standards

National Engineering Laboratory

Center for Building Technology

Washington, D C. 20234 October I960

NBSIR 80-2111-11

* • »

REVIEW AND REFINEMENT OF ATC 3-06 TENTATIVE SEISMIC PROVISIONS

REPORT OF JOINT COMMITTEE ON REVIEW AND REFINEMENT

MATIOftAll BTTJUCAtJ or standards

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Edgar V. Leyendecker, Editor, National Bureau of Standards

James R. Harris, Editor, National Bureau of Standards

Prepared for use by the:

BUILDING SEISMIC SAFETY COUNCIL

Sponsored by:

FEDERAL EMERGENCY MANAGEMENT AGENCY

Center for Building Technology

National Bureau of Standards

Washington, D.C. 20234

October 1980

U.S. DEPARTMENT OF COMMERCE, Phillip M. Klutznick, Secretary

Luther H. Hodges, Jr. , Deputy Secretary

Jordan J. Baruch, Assistant Secretary for Productivity,

Technology, and Innovation

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director
V *1- ' U . '> IIIfIIIIi
ABSTRACT

The Tentative Provisions for the Development of Seismic Regulations for

Buildings were developed by the Applied Technology Council to present,

in one comprehensive document, current state of knowledge pertaining to

seismic engineering of buildings. The Tentative Provisions are in the

process of being assessed by the building community. This report is

one of a series of reports that documents the deliberations of a group

of professionals jointly selected by the Building Seismic Safety Council

and the National Bureau of Standards and charged with reviewing the

Tentative Provisions prior to the conduct of trial designs. The group

is divided into nine technical committees, each of which focused on a particular portion of the Tentative Provisions . The nine committees

proposed recommendations for change to the parent group, the Joint

Committee, through a Coordinating Committee. The Coordinating Committee

made some modifications to the technical committees’ recommendations to

ensure consistency among the recommendations. This report documents the

actions of the Joint Committee on the 198 recommendations for change

that were presented to it. The first part of the report is a summary of

the results, and the appendices contain the full documentation for each

recommended change. The actions of each of the nine technical committees

is documented in a separate report.

Keywords

:

Building; building codes; building design; earthquakes;

engineering; standards; structural engineering.
I
Table of Contents

Page

1.0 Introduction 1

2.0 Summary of Activities 1

2.1 Development of the Recommendations for Ballot 1

2.2 Final Meeting of the Joint Committee 2

3.0 Joint Committee Ballot 5

4.0 Description of Appendices 6

APPENDICES

A Recommendations for Change as Balloted by the Joint Committee A-l

B Instructions for the Joint Committee Ballot B-l

C New Proposals Received at the Final Meeting of the Joint Committee... C-l

D Original Work Plan for the Project • D-l

E Roster of Participants E-l

1.0

INTRODUCTION

-he Tentative Provisions for the Development of Seismic Regulations

were developed by the Applied Technology Council (ATC) in an effort that

included a wide range of experts in the actual drafting of the provisions.

Two external review drafts were circulated to a large portion of the

interested and informed community of eventual users. However, because

the Tentative Provisions were innovative, doubts about them existed.

Consequently, an attempt was made to investigate these doubts and to

improve the Tentative Provisions where possible before an expensive

assessment of the Tentative Provisions was undertaken by conducting trial

designs

This review and refinement project was planned and conducted by the National

Bureau of Standards (NBS) with the advice and approval of the Building Seismic

Safety Council (BSSC) , a private sector organization formed in 1979 for the

purpose of enhancing public safety by providing a national forum to foster

improved seismic safety provisions for use by the building community. The

project was conducted in accordance with the Work Plan in Appendix D which

was agreed to by NBS and the Board of BSSC.

The assessment of the Tentative Provisions was performed using the

committee structure shown on the cover of this report. Nine technical

committees were formed with interests that collectively cover the Tentative

Provisions . The Joint Committee on Review and Refinement consists of

all voting members of the Technical Committees. The chairmen of the

Technical Committees form a Coordinating Committee. Membership of each

Technical Committee is made up of representatives of organizations that

have particular interest in the Tentative Provisions ; the participants

are listed in Appendix E of this report.

In addition to the voting members, each Technical Committee includes a non-voting member from each of the following organizations: The Applied

Technology Council, the Building Seismic Safety Council and the National

Bureau of Standards. The ATC representative served as a technical

resource to the committee since he was closely involved with the development of the provisions of interest to the committee. The NBS representative was the technical secretary throughout the effort. The BSSC

representative provided a link with the Building Seismic Safety Council,

which will be involved in trial designs and evaluations.

2.0 SUMMARY OF ACTIVITIES

2.1 Development of the Recommendations for Ballot

The initial meeting for all the committees was held on December 11, 1979,

at the National Bureau of Standards. The morning was devoted to a session

of the Joint Committee at which the proposed work plan for the project was

presented and discussed. The afternoon was devoted to organizational

meetings of the nine technical committees.

Following the initial meeting, the technical committees conducted their

business by correspondence and meeting (except Committees 1 and 7, which

relied entirely on correspondence) . The general sequence of activity

was as follows:
1. Written proposals for change collected;

2. Public work sessions on the proposals for change and development

of a ballot for the committee recommendations;

3. Letter ballots;

4. Additional work sessions (for some committees) to resolve disputes

and prepare additional ballots;

5. Submission of recommendations to the Coordinating Committee.

The activities of each committee are fully documented in the report in

this series of reports for which the last digit of the report number matches

the committee number (e.g. report NBSIR 80-2111-3 documents the activities

of Technical Committee 3)

The Coordinating Committee examined problems of overlap and conflict among

the recommendations of the nine committees, modifying a few of the recommentions in the process. The final recommendations for ballot by the

Joint Committee were then distributed at the July 16-17, 1980 meeting.

2.2 Final Meeting of the Joint Committee

The final meeting of the Joint Committee was held on July 16 and 17 at the

National Bureau of Standards. Each committee's recommended changes were

discussed in the following format:

1. The committee members (usually the chairman) presented their

reasons for the proposed change.

2. For those items with significant dissent within the committee,

a committee member presented the minority viewpoint.

3. The ATC representative on the committee presented his opinion

of the recommended changes.

4. The audience participated in an open discussion of the committee's

recommended changes.

Following is a very brief summary of the discussion and actions taken at

the meeting.

Committee l's two recommendations were presented by the secretary, Bruce

Ellingwood. Neville Donovan, the ATC representative, registered opposition

to both. Discussion was then opened on the Coordinating Committee's

special ballot items concerning reduction of the Seismicitiy Index for

Map Areas 1 through 5. E. V. Leyendecker pointed out that the Seismicity

Index items were placed on the ballot because of the considerable interest

in them by a number of committees. This was not intended to imply

endorsement, instead it was intended as a means to place the issue

before the full Joint Committee.

Committee 2 used several members to present their recommendations and

noted that about six of their 27 recommendations were simple editorial

clarifications. Roland Sharpe, the ATC representative, agreed with each

of the recommended changes and further noted a desire to see the trial

2
designs incorporate a a test of both the original and the newly recommended

drift limits. There was very little discussion.

Committee 3's recommendations were presented by the chairman, Richard Simon.

Discussion turned to the chapter on the soil-structure interaction provisions. Committee 3 had originally recommended that the chapter be

deleted, but had withdrawn the recommendation within the Coordinating

Committee in order to resolve a conflict with a recommendation from

Committee 2 (item 2/6 - note: the number preceding the slash identifies

the Committee making the recommendation, the number following the slash

is the recommendation number for that committee; see section 3 for more

information) . Henry Degenkolb, the ATC representative, explained that

he had not opposed Committee 3’s recommendation. Ron Mayes, an ATC

representative on another committee, argued that deletion of the entire

chapter exceeded the scope of review and refinement committees. The

only other item of discussion was that Howard Simpson and a few other

members of Committee 2 opposed ballot item 3/1, stating that the proper

soil profile category for sites not fitting the description for any of

the three types was type S2.

Committee 4’s recommendations concerning concrete piles (ballot items

4/4, 4/6, 4/7, S/6, S/7, and S/8) were presented by Neil Hawkins, who

acted for the chairman. Loring Wylie, the committee’s representative

from the Structural Engineers Association of California (SEAOC) , opposed

item 4/6 in particular, citing the importance of category D buildings

and the lack of substantiating data on pile performance in large earthquakes.

Richard Simon, the chairman of Committee 3, opposed ballot item 4/6

because it would allow the use of precast-prestressed piles for category

D buildings. Hawkins argued for the recommendation, stating that the

lateral reinforcement used in such piles in California made them weaker

than those in other regions of the country. There was also some discussion

of the recommendations concerning the use of exposed strand for connecting

precast piles to pile caps.

Frank M. Fuller of Raymond International Builders presented revisions to

the provisions for cased and uncased concrete piles in category B and C

buildings. One of his objectives was to reverse the present provision

which requires more reinforcement in a cased pile than in an uncased pile.

His proposed revisions were not identical to any of those proposed by the

committees and therefore were not on the ballot for the Joint Committee.

His proposals are included in Appendix C of this report.

Hawkins then presented Committee 4’s recommendation concerning the use

of the March 1980 draft proposed for Appendix A of American Concrete

Standard ACI 318 (item 4/12) , which elicited considerable discussion.

Proponents argued that the draft Appendix A contains several technical

improvements and that the economic impact would be large. Opponents

were principally concerned that several different issues were covered in

the one recommendation, making it an "all-or-nothing" proposition, and

that the version of Appendix A being referred to was not a real standard

but only a subcommittee draft, which would be subject to future change.

Hawkins next presented Committee 4’s other recommendations. Ed Zacher

of Committe 2 pointed out that Committee 2 had rejected a proposal similar

3
to item 4/3. Tony Wintz of Committee 8 stated that items 4/8 and 4/9

were within the scope of Committee 8, not Committee 4, and opposed those

recommendations because Committee 8 had not had the opportunity to

consider them.

Committee 5's recommendations were presented by George Hanson, co-chairman

of the committee. Ed Johnson, the SEAOC representative on the committee

expressed opposition to the committee’s recommendations. Johnson claimed

the committee membership was unbalanced in the favor of the masonry industry.

Ron Mayes, the ATC representative, stated that the committee needed more

time to complete its work. Mayes opposed several of the specific recommendations. The open discussion covered many issues, but one of the most

substantial was Howard Simpson's opinion that the committee's grouping

of recommendations made it impossible to conscientiously cast a ballot.

Simpson gave an example of one ballot item that he felt included five

substantive changes, four of which he favored and one of which he opposed.

E. V. Leyendecker, the committee secretary indicated that he had attempted

to group the numerous ballot items to reduce the total number of ballot

items below those considered by the committee.

Committee 6’s recommendations were presented by William Sontag, who

acted for the chairman. Charles DeMaria, the SEAOC representative,

opposed ballot item 6/5, which deals with the maximum allowable axial

force in columns of special moment frames. William Smith, an alternate

on the committee, presented a set of proposals prepared by the American

Iron and Steel Institute for modifying the provisions to include an R

factor and special design rules for steel eccentric braced frames. The

proposals were not a part of Committee 6's recommendations and therefore

were not included on the ballot. They are included in Appendix C of

this report.

Committee 7's recommendations were presented by the chairman, Dan Brown.

Ed Zacher, the ATC representative expressed opposition to items 7/6, 7/9,

and 7/14. A short discussion of item 7/9 followed.

Committee 9's two recommendations were presented by the chairman, Norton

Remmer. The only discussion was on the issue of existing buildings,

which was unrelated to the recommendations. Ed Pfrang, the chairman of

the Joint Committee, stated in response to a question that there were no plans to include existing buildings in the trial designs.

Committee 8's recommendations were presented by the chairman, Robert Sockwell.

Tom Wosser, the ATC representative, supported the recommendations and stated

that the first four were mostly editorial and that the recommendations for

elevators were a real improvement. A question was raised concerning the

reference to American National Standard A17.1 in item 8/6. Sockwell

responded it was not the intent that A17.1 be ". . .the singular acceptable

design standard for elevators. . . [but] the committee considered A17.1

to be the most up-to-date and appropriate standard for reference to

seismic design of elevator systems."

Committee 5 then reported back to the Joint. Committee with a proposal

for a new ballot. The new ballot had been prepared by subdividing the

original items into smaller units (more ballot items) . They also prepared

4
an accompanying document that included the record of their committee

ballot, a description of the effect of the change, and a comment from

the ATC representative for each item. They pointed out that the new

proposal was merely a repackaging of the previous recommendations in

order to facilitate voting, i.e. that they had not changed the substance

of their recommendations. Where grouping of items was done, it was with

ATC concurrence. Ron Mayes, the ATC representative, told the Joint

Committee that he felt the new proposal was a significant improvement

and that he agreed with most of the recommendations. The Joint Committee

accepted their proposal, which meant that the portion of the original

ballot dealing with Committee 5 was to be disregarded and eventually

replaced by a supplementary ballot.

Committee 4 then proposed that they be allowed to prepare a supplementary

ballot to be distributed along with Committee 5's supplementary ballot.

Their proposal was somewhat different, however. The supplementary

items would be a detailed breakdown of the technical improvements involved

in the recommendation to use the March 1980 draft version for Appendix A

of ACI 318 (ballot item 4/12). Furthermore, the supplementary items

would not replace any of -the original ballot items, but would only be

effective if item 4/12 failed to pass the Joint Committee. After some

discussion on the propriety of the proposal, the Joint Committee agreed

with Committee 4. Committee 4 then identified and prepared seven items

for the supplementary ballot.

Roland Sharpe of ATC pointed out that some recommendations for the Joint

Committee from a given committee were closely related to proposals in

other committees and requested that the results of these deliberations

be made known. James Harris of NBS produced a list of such items closely

related to issues discussed by Committee 2. It was agreed that pertinent

excerpts from the minutes of the various committees would be collected

and distributed to the membership of the Joint Committee.

The instructions for the Joint Committee ballot (and the supplementary ballot)

including the pertinent excerpts of committee minutes are included in

Appendix B of this report.

3.0 JOINT COMMITTEE BALLOT

Tables 1, 2, and 3 indicate the results of the ballots of the Joint Committee.

Each item is listed in tables 1, 2 and 3 with an item number and a short

title. The first digit in the item number corresponds to the technical

committee recommending the change, and the number following the slash ("/")

is a consecutive number for the recommendations within that committee.

The Coordinating Committee is the final author of those recommendations

for which an "S" is the original character of the item number. The

complete text, the vote of the sponsoring technical committee, and the

reason for the change for each recommendation are included in Appendix A

of this report. (In the case of Committee 5, only the final recommendations

agreed to at the July 16-17 meeting are included; they replace the

original proposals of Committee 5.) The item number is the easiest way

to find the particular item in Appendix A, since the items are arranged
consecutively in Appendix A. Each recommendation also appears in the

individual committee reports referred to in the previous section.

Table 1 contains the 143 items that passed with a 2/3 or greater majority,

which is the criterion for passage established at the initiation of the

project. Table 2 contains 19 items that did not pass by that criterion

but which did have a simple majority of affirmative votes. Table 3 contains 36 items that did not receive a simple majority of affirmative

votes. Because of the supplementary ballot for Committees 4 and 5 that was agreed to at the July 16-17 meeting, there were actually two ballots

cast. Of the 65 eligible votes, 52 cast the first ballot and 42 cast

the second ballot, which dealt only with the recommendations of Committee

5 and the supplementary recommendations of Committee 4.

4.0 DESCRIPTION OF APPENDICES

There are five appendices to this report, which contain the official documents

of the Joint Committee. Appendix A contains all of the recommendations that

the Joint Committee balloted, whether they were approved or not. The

recommendations in Appendix A actually originated in the official documents

of the nine technical committees and the Coordinating Committee. The other

appendices simply complete the documentation of the Joint Committee's

actions. There are no official minutes for the Joint Committee's meetings,

although the proceedings of the final meeting are described in section 2.2

of this report.

6
TABLE 1 ITEMS WITH GREATER THAN 2/3 MAJORITY

ITEM SHORT TITLE YES NO

1/1 CONTOUR MAPS 33 16

2/1 SNOW LOAD DEFINITION 34 13

2/2 GL DEFINITION 47 1 2/3 QS DEFINITION 46 2 2/4 ALLOW ALTERNATE ANALYTICAL PROCEDURE 48 0 2/5 ROCK CLASSIFICATION 47 1 2/6 SOIL" STRUCTURE INTERACTION ANALYSIS 45 2 2/7 NAME OF INVERTED PENDULUM 46 1 2/8 R VALUE FDR MIXED STRUCTURES ...................... 47 1 2/9 DRIFT COMPATIBILITY 43

2/10 ORTHOGONAL COMBINATION OF LOADS 42

2/11 DISCONTINUITIES IN STRENGTH BY STORY 45

2/12 REDUNDANCY 43

2/13 TIES AT JOINTS 46

2/14 NAME OF VX 46

2/15 USE OF EQUATION FOR CS 46

2/16 RESULTANT OF OVERTURNING 43

2/17 PX DEFINITION 46

2/18 SHEAR PANEL DEFINITION 45

2/19 HEIGHT LIMITS 45

2/20 ALLOW ALTERNATE LOAD ANALYSIS 47

2/21 EXCEPTION TO DRIFT LIMSIT 40

2/23 CALCULATION OF P-DELTA EFFECT 43

2/24 COMMENTARY ON ALTERNATE ANALYTICAL PROCEDURE ...... 44

2/25 COMMENTARY ON CLASSIFICATION OF FRAMING SYSTEMS ... 36

2/26 COMMENTARY ON DRIFT AND P-DELTA 42

2/27 COMMENTARY ON SPECTRAL COEFFICIENTS 39

3/1 COEFFICIENT S FOR UNKNOWN SOIL PROFILE 38

3/2 ACCEPTABLE STRAINS IN LIEU OF ELASTIC LIMIT 48

3/3 TIES BETWEEN SPREAD FOOTINGS 43

3/5 FLEXURE ON PRECAST PILES 46

4/1 MILL TESTS FOR REINFORCING STEEL 45

4/3 VERTICAL ACCELERATION CN PRESTRESSED CONCRETE ..... 32 l 4/A PILE CAP CONNECTION 40

4/7 CATEGORY C PRECAST-PRE STRESSED PILES 32 1 4/8 VERTICAL FORCE ON NONS TRUCTUR AL COMPONENTS 33 l 4/9 WALL CONNECTION DESIGN COEFFICIENT 34 1 4/10 COMMENTARY ON CATEGORY C DETAILS 37

4/11 COMMENTARY CN ORTHOGONAL EFFECT IN SLABS •••••••.•• 38

4/13 REFERENCE ACI 318-77 33

4/14 ALLOW PRECAST AND/OR PRESTRESSED CONCRETE 33

4/16 REINFORCING STEEL 30

4/17 UNTOPPED PRECAST AND/OR PRESTRESSED COMPONENTS .... 31 4/18 FLAT SLAB CONSTRUCTION ••••••••••••• 35

4/19 COMMENTARY ON FLAT PLATE FRAMES 31

5/1 BACKGROUND 39

5/2 STRENGTH ••••••• 39

5/3 DESIGN PROCEDURES 38

5/4 S. P. C. A 40

5/5 S. P. C. B 36

5/6 MISC. REQUIREMENTS - 38

5/7 MISC. REQUIREMENTS 39

S/10 S. P. C. B - COLUMNS. ETC 33

5/13 JOINTS* GLASS MASONRY 40

5/14 REINFORCEMENT DEVELOPMENT 40

5/15 CONCENTRATED LOADS 38

5/16 S. P. C. C - CONSTRUCTION LIMITATIONS ••••.•••••••• 39

5/17 WALLS* HOLLOW UNIT MASONRY 39

5/21 SPECIAL INSPECTION STRESSES, CORE TESTS 38

5/23 MATERIAL LIMITATIONS 35

5/24 MASONRY WALLS* GROUT AND MORTAR STRENGTH 37

5/25 MATERIAL LIMITATIONS 33 1 5/26 S. P. C. D - CONSTRUCTION LIMITATIONS 38 l 5/27 SHEAR WALL ANO OTHER REQUIREMENTS 36 3

ABST.

3

5

4

44

4

55

4

3

3

3

7
5 A / 1 CLARIFY DEFINITIONS AO 0 5A/3 NEW DEFINITIONS 33 7 5A/4 DELETE DEFINITIONS 34 5 5A/5 DELETE DEFINITIONS ,T. ......... 26 13

5 A/6 DELETE DEFINITION 37 2 5A/7 DELETE DEFINITION 33 7 5A/8 MODIFY DEFINITION 39 1 5A/S REFERENCE DOCUMENTS 38 2 5 A / 1 0 SYMBOLS 38 1 5 A / 1 1 UNIT CRITERIA AND ABSORPTION 37 2

5 A / 1 2 GLASS UNITS 34 3

5A/13 SHRINKAGE 30 7 5 A / 1 5 LIME. MORTAR 38 1 5 A/ 1 8 CONSTRUCTION 36 3

5A/20 STARTER COURSES 34 ( 6 5A/21 CONTACT SURFACES 38 2 5A/22 ADJACENT WYTHES 38 2 5A/25 UNBURNED CLAY MASONRY 39 1 5A/27 TOOTHING 37 3 5A/28 MISC. GROUTED MASONRY REQUIREMENTS 39 2 5A/30 VERTICAL BARRIERS 36 3 5A/32 GROUT THICKNESS 38 2 5A/35 GROUTING 38 1 5A/38 PARTIALLY REINFORCED MASONRY 37 2 5A/39 GLASS MASONRY 29 6 5A/40 DETAILED REQUIREMENTS 36 3 5A/41 DISSIMILAR UNITS 36 2

5 A/42 UNREINFORCED MASONRY DESIGN 36 3 5A/43 UNREINFORCED SOLID CLAY BRICK MASONRY DSGN. PROC. .36 4 5A/45 UNREINFORCED SOLID CLAY MASONRY DESIGN ............ 35 4 5A/46 UNREINFORCED CONCRETE MASONRY OESIGN PROCEDURES ... 35 5 5A/48 UNREINFORCED CONCRETE MASONRY DESIGN 36 4 5A/51 UNREINFORCED HOLLOW CLAY MASONRY OESIGN 34 7

5 A/53 UNREINFORCED 4OLL0W CLAY MASONRY DESIGN 36 4 5A/54 REINFORCED MASONRY 38 2 5A/55 ANCHORAGE OF REINFORCEMENT 33 8 5A/56 OTHER DESIGN REQUIREMENTS 38 2 5A/59 NOMENCLATURE 33 6 5A/63 OTHER DESIGN REQUIREMENTS 38 2 5A/65 ANCHORAGE REQUIREMENTS 36 5 5 A / 67 OTHER CONSTRUCTION 39 1 5 A/69 CLARIFICATION OF QUALITY CONTROL 39 1 5A/70 SEISMIC QUALITY CONTROL 35 6 5A/71 MISCELLANEOUS REQUIREMENTS 38 3 5A/73 CORE TESTS AND TABLES 36 3 5A/75 TITLE 35 6 5A/77 TABLES ••••••.•••• 36 5 5 A/79 STRESSES 36 4 5A/81 FOOTNOTE 36 4 6/1 ALLOWABLE FOR MEMBERS WITH EXTRA CAPACITY 44 3 6/2 ALLOWABLE SHEAR 41 5 6/3 CATEGORY B MOMENT FRAME 44 3 6/4 CATEGORY C AND D MOMENT FRAMES 35 12

6/6 BEAM-COLUMN JOINT PANEL ZONE 42 4 7/1 REFERENCES FOR PLYWOOD 45 1 7/2 REFERENCE FOR ONE AND TWO FAMILY CODE 44 2 7/3 PHI FACTOR FOR 01 APHRAGMS AND SHEAR WALLS 39 7 7/4 TABLE OF PHI FACTORS 37 3 7/5 ECCENTRIC JOINTS 40 5

7/7 PLYWOOD SHEAR WALLS IN CATEGORY C 40 6 7/8 PLYWOOD SHEAR WALLS IN CATEGORY D •••••• 41 4 7/10 BOTTOM PLATES ..••••••.••• 38 3 7/11 BLOCKING IN PLYWOOD SHEAR WALLS’ - 34 11 7/12 TABLE FOR PLYWOOD SHEAR WALLS 42 __ 4 7/13 TABLE FOR PLYWOOD DIAPHRAGMS 41 5 7/15 REFERENCES FOR PLYWOOD 44 1 8/1 OUT-OF-PLANE BENDING * 42 3 8/2 COMMENTARY ON OUT-OF-PLANE BENDING 42 2 8/3 TABLE 8-B FOOTNOTE ON URBAN AREA 43 2 6/4 TABLE 8-B ON VENEERS 44 1 8/5 EXCEPTIONS FOR ELEVATORS 37 7 8/6 NEW SECTION ON ELEVATORS - 37 5 8/7 TABLE 3-B ON ELEVATORS 38 5 8/8 TABLE 8-C ON ELEVATORS 39 4 9/1 TITLE OF CHAPTER 1 - 42 5 9/2 DATE PERMIT ISSUANCE 45 2 S/6 ALTERNATE REINFORCEMENT FOR PILES 39 7 S/7 EXPOSED STRAND FOR CATEGORY 34 12

S/8 EXPOSED STRAND FOR CATEGORY C 37 9

8

2

23

33

2

223

35

5

3322

22

2

132

3

37

3

4

3

23

22

12

2

12

3

2

12

2

1

13

1

12

2

5

6

5

56

66

6

776

7

67

6

677

87

7

3

9

995

5

6

66
TABLE 2 ITEMS WITH A SIMPLE MAJORITY

I TEM SHORT TITLE YES NO ABST.

1/2 ACTIVE FAULT DEFINITION 30 19 3

2/22 REVISE TABLE OF DRIFT LIMITS 28 18 6

4/12 USE OF 318 APPENDIX A 28 18 6

4/15 PROVISIONS FOR PRECAST ANO/OR PRESTRESSED CONC. ... 24 16 2

5/11 HIGH-LIFT GROUT CONSTRUCTION 22 18 2 5/18 BOLT PLACEMENT 24 17 1 5/20 GROUT .................................. P? 1 Q

5/28 TABLE 12.1 ........................................ 1 *7 5 A/ 2 OELETE LOAD-BEARING DEFINITION 25 15

o

2 5A/17 MIXING ........................................ 23 1 f\ 3 5A/19 JOINTS 23 17 2 5A/23 TEMPLATES ......................................... 21 20 1 5A/44 UNREINFORCED SOLID CLAY ALLOWABLE STRESSES 21 20 1 5A/50 AXIAL COMPRESSIVE STRESSES FOR WALLS 24 17 1 5A/64 HOOK REQUIREMENTS • ••• 21 20 1 5A/68 QUALITY CONTROL • 22 19 1 7/9 ANCHOR BOLT SPACING 23 22 7 S/4 SEISMICITY INDEX* MAP AREA 2 25 21 6

MULTIPLE CHOICE ITEM A B C D 5/8 MINIMUM WALL THICKNESS: CHOOSE ONE OPTION 16 2 0 14

TABLE 3 ITEMS WITH LESS THAN A SIMPLE MAJORITY

I TEM SHORT TITLE YES NO ABST.

<*/6 CATEGORY 0 PILE REQUIREMENT 21 2* 7 5/9 S. P. C. 3 - WALLS 16 25

5/12 MORTAR AND GROUT STRENGTH 17 24

5/19 SHRINKAGE CONTROL 13 23

5/22 MATERIAL LIMITATIONS 13 23

5 A / 1 4 CEMENT 17 23

5 A / 1 6 GROUT CONSISTANCY 20 20

5A/24 TIE PLACEMENT 18 23

5A/26 GROUTED MASONRY 19 21

5 A/29 CLEANOUTS ••••••••••••• IS 23

5 A / 3 1 REINFORCED CONSTRUCTION 20 20

5A/33 FOLLOW UNIT •••••••••••••.•• 14 25

5A/34 GROUT PROCEDURES 19 21

5A/36 LIFTS 16 23

5A/37 CLEANOUT 20 20

5A/47 UNREINFORCED CONCRETE MASONRY ALLOWABLE STRESSES .. IS 23

5 A/49 UNREINFORCED HOLLOW CLAY MASONRY DESIGN PROCEDURES 19 22

5A/52 SHEAR WALL STRESSES •...••••••••••••• 19 22

5A/57 REINFORCED MASONRY WALLS •••••••••••••• 19 22

5A/53 AXIAL WALL STRESSES 17 23

5A/60 SHEAR STRESS ALLOWABLES 20 21

5A/61 PLACEMENT 20 .21 5A/62 AXIAL COLUMN STRESSES 17 22

5A/66 WALL SHEAR 19 22

5A/72 REQUIRED STRENGTHS 18 22

5 A /74 MINIMUM THICKNESSES •••••• ••••••••••••• 20 21

5A/76 H/T RATIOS 18 23

5A/78 STRESSES 16 25

5A/80 FOOTNOTE 20 21

6/5 AXIAL FORCE IN SPECIAL MOMENT FRAME 19 27

7/6 NAILS IN CATEGORY C 21 24

7/14 EXCEPTION FOR CONVENTIONAL CONSTRUCTION 20 26

S/1 1 SEISMICITY INDEX, MAP AREA 5 19 27

S/2 SEISMICITY INDEX. MAP AREA 4 •••••• 19 27

S/3 SEISMICITY INDEX, MAP AREA 3 21 25

S/5 SEISMICITY INDEX. MAP AREA 1 23 23

11

1

12

2

12

12

3

2

32

1

1

112

1

13

12

1

11

16

76

6

66

6

9

APPENDIX A

RECOMMENDATIONS FOR CHANGE

AS BALLOTED BY THE

JOINT COMMITTEE

This appendix contains the 198 items balloted by the Joint Committee,

arranged as follows:

1/1-1/4 The recommendations of Technical Committee 1 (items 1/3

and 1/4 were replaced on the ballot by items S/4 and S/5).

2/1-2/27 The recommendations of Technical Committee 2.

3/1-3/

4/1-4/12

The recommendations of Technical Committee 3 (item 3/4 was

replaced on the ballot by item S/6 and item 3/6 was deleted

by the Coordinating Committee)

The initial recommendations of Technical Committee 4 (items

4/2 and 4/5 were replaced on the ballot by items S/4 and

S/7).

4/13-4/19 The supplementary recommendations of Technical Committee 4.

5A/1-5A/81* The recommendations of Technical Committee 5 for chapter 12A

(these are also in the form of corrections marked on the

original text of the Tentative Provision and are immediately

followed by a tabulation of comments by the committee and bv

ATC).

5/1-5/28 The recommendations of Technical Committee 5 for chapter 12

(these are in the form of corrections marked on the original

text of the Tentative Provisions and are immediately followed

by a tabulation of comments by the committee and by ATC)

6/1-6/6 The recommenda tions of Technical Committee 6.

7/1-7/15 The recommendations of Technical Committee 7.

8/1-8/8 The recommendations of Technical Committee 8.

9/1-9/2 The recommendations of Technical Committee 9.

S/l-S/8 The recommendations of the Coordinating Committee

Items 5A/1 - 5A/81 follow items 5/1 - 5/28 in tables 1, 2 and 3

of this report.
IIII
COMMITTEE 1

A1
JOINT

5 ALLOT

JUMBER 2.0 COMMITTEE ACTIONS

2.1 Recommendations for Change

Technical Committee 1 on Seismic Risk Maps recommends to the Joint Committee

four changes to Section 1.4 of the ATC Tentative Provisions . The first two

originated from within Committee 1.

- (1) The design ground motions defined in terms of Effective Peak Accleration or Effective Peak Velocity-Related Acceleration should be represented

by contour maps (in percent gravity) rather than by counties.

Reason : Contours permit a degree of judgment by the user without penalizing

the building industry in portions of the country where earthquake and fault

records are not as abundant as in the western states and where the zone boundaries are not well defined. The increase in accelerations between

zones is enough to penalize buildings in these border areas, some of which

are areas of heavy construction. Contour lines are easier to relocate as additional data become available. Seismic risk in large counties close

to zones of active faulting also could be treated more consistently.

Opposing points of view were that code administrators prefer a county-type

map, and the specification of zones avoids the need to extrapolate ground

acceleration at certain boundaries of the contiguous 48 states.

1/2 (2) Change Section 1.4.4 to read: "No new building or existing building

which is, because of change in use, assigned to Category D shall be sited

on an active fault." Add the following definition : "An active fault is one on which there is evidence of tectonic movement in the past 10,000

years, i.e., Holocene displacement."

Reason: Editorial improvement, includes definition of an active fault.

However, one affirmative vote was cast with the reservation that the definition does not cover fault strands, conjugate faults, or associated faults

for which no direct evidence of movement exists but which are so related

to an active fault that activity on one may be likely as on the other.

In addition to these proposals, several proposals for changing the values

of Seismicity Index in Table 1-B of the ATC Tentative Provisions were sent

to Committee 1 for ballot as well as to other Committees. The reasons

advanced for the proposed changes are described in detail in Section 4,

Correspondence. Briefly, it was felt that buildings located in map areas 1 and 2, and probably map area 3, would remain elastic under design ground

accelerations and thus additional requirements for detailing to insure

ductility over existing practice are. not necessary. The view was also

expressed that in map areas 4 and 5, the sudden additional requirements

for detailing for ductility are not supported by adequate background studies.

The ballot of Committee 1 on the proposed changes to the seismicity index

classification resulted in the following proposed changes:

A2
COMMITTEE 2

A3
JOINT BALLOT NUMBER 2/1

REVIEW AN? REFINEMENT 07 TENTATIVE SEISMIC PROVISION?

PROPOSE!) CHANGE

TECHNICAL COMMITTEE: 1

' 2 , STRl'CTURAL DESIGN COMMITTEE ITEM NUMBER: 1-7

ATC-3-C ' REFERENCE: 2JL Add the following sentence immediately following the definition of SNOW LOAD.

EXCEPTION: Where snow load is less than 30 pounds per square foot, no part

of the load need be included in seismic loading.

FINAL BALLOT: _5 YES

_2 NO

_1 ABSTAIN

_2 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The change introduces consistency with the model building codes and simplifies

computations for those locations in which only a small snow load would be

considered simultaneously with seismic loads. The minority view was that the

current ATC provision (use of from 20% to 70% of the full snow load, depending

on the judgement of the building official) was an adequate allowance for the

small probability of simultaneous occurrence of snow load and seismic load.

A4
JOINT BALLOT NUMBER 2/2

REVIEV.' AND RE r INENENI OF TENTATIVE SEISMIC PROVISIONS

PROPOSE! 1 CHANGE

TICHNICA! C0!2:I7TEE: v 2 , STRVCT’CRAL DESIGN COMMITTEE ITEM NUMBER: 1 “ 8

ATC-3-Or SECTION REFERENCE: 2 - 2

Change the definition to read as follows:

Q = The effect of live load, reduced as permitted in section 2.1

FINAL BALLOT: 8 YES

0 N O

0 ABSTAIN

2 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The added phrase clarifies the use of live load reduction based on tributary

area when combining the effects of live load and seismic load.

A5
JOINT BALLOT NUMBER 2/3

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL CO'CUTTEE: f‘2, STRUCTURAL DESIGN COMMITTEE ITEM NUMBER:

AT C-3-06 SEC i ION REFERENCE: 2.2

Change the definition of to read as follows:

* Qg= The effect of snow load, reduced as permitted in section 2.1 .

FINAL BALLOT: YES

_Q NO

_Q ABSTAIN

_2 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The added phrase clarifies the use of the reduction from the full design snow

load when combining the effects of snow load and seismic load.

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JOINT BALLOT NUMBER 2/4

REVIEW ANT REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: *2, STRUCTURAL DESIGN COMMITTEE ITEM NUMBER:

ATC-3-Oo SECTION REFERENCE: 3.1

Change the second and third sentences to read as follows:

The design seismic forces, and their distribution over the height of the

building, shall be established in accordance with the procedures in

Chapter 4 or Chapter 5; the corresponding internal forces in the members

of the building shall be determined using a linearly elastic model. An

approved alternate procedure may be used to establish the seismic forces

and their distribution; the corresponding internal forces and deformations

in the members shall be determined using a model consistent with the

procedure adopted . Individual members shall be sized. . .

FINAL BALLOT: 8 YES

0 N O

0 ABSTAIN

2 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The revision permits the use of methods incorporating inelastic models of

material behavior, subject to explicit approval of the authority.

1-10

A7
JOINT BALLOT NUMBER 2/5

REVIEW ANT REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHN ICAL CO'EIITTEE : ft 2, STRUCTURAL DESIGN COMMITTEE ITEM NUMBER : 1-H

ATC-3-0- SETT ION REFERENCE : 3.2.1

Change the first subparagraph under soil profile type 1 to read as follows:

II Rock of any characteristic, either shale-like or crystalline in nature.

Such material may be characterized by a shear wave velocity greater than

2500 feet per second or by other appropriate means of classification , or

FINAL BALLOT: R YES

0 N O

0 ABSTAIN

2 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The added phrase removes the implication that shear wave velocity tests are necessary in order to class a subsoil material as rock.

A8
JOINT BALLOT NUMBER 2/6

REVIEW ANT REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL CCUDIITTEE : f-2, STRUCTURAL DESI GN COMMITTEE ITEM NUMBER: 1-12

ATC-3-06 SECTION REFERENCE: 3.2.3

Change to read as follows:

Tire base shear, story shears, overturning moments, and deflections determined

in Chapter 4 or Chapter 5 may be modified in accordance with procedures set

forth in Chapter 6 to account for the effects of soil-structure interaction.

FINAL BALLOT: 8 YES

0 NO

Q ABSTAIN

2 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

Two issues are involved in this item. First, the committee decided to retain

the provision allowing soil-structure interaction analysis because it felt

that Chapter 6, Soil-Structure Interaction, was a worthwhile component of the

overall seismic design provisions. Second, the revision to the provision was

made' in recognition of the possible increase in force effects due to the

increased P-delta effect resulting from rotation of the base of a building.

A9
JOINT BALLOT NUMBER 2/7

REVIEW ANT REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE : V2, STRl'CTERAL DESIGN COMMITTEE ITEM NUMBER: 1-13

ATC-3—Oc Si 77 1

•’ '• REEL r JEW JE : 3.3.1

Delete the word "Special" from the third sentence of the first paragraph.

FINAL BALLOT: 8 YES

0 N O

0 ABSTAIN

2 DID NOT VOTE

COMMENT ON PROPOSED CHANGE

Since a "special" inverted pendulum is nowhere distinquished from any other

type of inverted pendulum, the removal of the word prevents possible confusion.

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A10
JOINT BALLOT NUMBER 2/8

REVIEW and refinement of tentative seismic provisions

PROPOSED CHANGE

TECHNICAL CO' Eli IT EE : 42, STRUCTURAL DESIGN COMMITTEE ITEM NUMBER

ATC-3-06 SECTION REFERENCE: 3. 3.2(A)

Change the first paragraph to read as follows:

R VALUE. The value of R in the direction under consideration at any level

shall not exceed the lowest value of R obtained from Table 3-B for the

seismic resisting system in the same direction considered above that level.

FINAL BALLOT: 8 YES

0 N O

0 ABSTAIN

2 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The revisions clarify the original intent of the provision.

1-14

All
JOINT BALLOT NUMBER 2/9

REVIEW AN? REFINEMENT OF TENTATIVE SEISMIC PP^UISIONF

PROPOSED CHANGE

TECHNICAL COMMITTEE: vC, STRUCTURAL DESIGN COMMITTEE ITEM NUMB R: 1-16

ATC-3-0r SECTION REFERENCE: — 3.3.4(c)

<; ) Change to read as follows:

DEFORMATIONAL COMPATIBILITY. Every structural component not included in the

seismic force resisting system in the direction under consideration shall be

investigated and shown to be adequate for the vertical load-carrying capacity

and the induced moments resulting from the design story drift, as determined

in accordance with Sec. 4.6.

FINAL BALLOT : YES

0 N O

Q ABSTAIN

2 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The revision has the effect of requiring a check on the ability of the seismic

resisting system to maintain vertical load carrying capacity when subject to

the lateral displacement of the seismic resisting system in the orthogonal

direction. (For example, consider the ability .of a bearing and shear wall

to support vertical load when the wall is laterally supported by an unbraced

frame). The provision already required such a check for structural components

that were not part of the seismic resisting system.

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A12
JOINT BALLOT NUMBER 2/Ii

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: r I . S TRUCTURAL DESIGN COMMITTEE ITEM NUMBER: 1-17

AT C- 3-0- SECTION REFERENCE: 2.7.2

Change to read as follows:

ORTHOGONAL EFFECTS. In buildings assigned to Category B, the design seismic

forces may be applied separately in each of two orthogonal directions .

In buildings assigned to Category C and D, the critical load effect due to

direction of application of seismic forces on the building may be assumed

to be satisfied if components and their foundations are designed for the

following combination of prescribed loads: 100 percent of the forces for

one direction plus 30 percent of the forces for the perpendicular direction.

The combination requiring the maximum component strength shall be used.

EXCEPTION : Diaphragms, and components of the seismic resisting system

utilized in only one of two orthogonal directions need not be designed

for the combined effects.

FINAL BALLOT: J_ YES

_1 NO

_0 ABSTAIN

_2 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The objective in revising the provision is to reduce the amount of unnecessary

computation required. The committee believes that more improvement toward

this objective may be possible and looks for the trial designs to provide

such information.

A13
JOINT BALLOT NUMBER 2/11

REVIEW AN? REFINEMENT OF TENTATIVE SEISMIC PROVISION?

PROPOSED CHANGE

TECHNICAL COME TILL: V2. STRUCTURAL DESI GN COMMITTEE ITEM NUMBER: 1-18

ATC-3-06 SECTION REFERENCE: 3.6.2(A) and 3.7.

Change the second line of 3.6.2(A) to read as follows: . . .shall conform to

the requirements of Sec. 3.7 (except Sec. 3.7.3 and Sec. 3.7.12). . .

Change 3.7.3 to read as follows:

For Buildings assigned to Seismic Performance Categories C or D the design of

the building shall consider. . .

FINAL BALLOT: 8 YES

0 N O

0 ABSTAIN

2 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

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The revision removes the potential inconsistency of requiring formal consideration

of strength discontinuities for buildings in which formal consideration of

stiffness discontinuities is not required. Consideration of discontinuities in

stiffness need not be formally considered for buildings in Seismic Performance

Category B (to wit: Modal Analysis is not required for buildings in Category B with vertical irregularities).

A14
JOINT BALLOT NUMBER 2/12

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COM'.ITTEE : *2, STRl CTURAL DESIGN COMMITTEE ITEM NUMBER: 1-19

ATC-3-06 SECTION REFERENCE: 3.7.4

i

; i) Change to read as follows:

The design of a building shall consider the potentially adverse effect that

the failure of a single member, connection, or component of the seismic

resisting system would have on the stability of the building.

FINAL BALLOT : 7 YES

1 N O

0 ABSTAIN

2 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

No guidance is given on just how redundancy is to be checked.

The revision reduces, slightly, the magnitude of this problem.
JOINT BALLOT NUMBER 2/13

RFUIEU AN? REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TEC’riN I CAL C0>2I1TTEE : 1

: 2 , STRUCTURAL DESIGN COMMITTEE ITEM NIDSEK: 1-20

AT C-3-0c StCi:::. REFERINFE: 3.7.3

Change the first line to read:

All parts of the building between separation joints shall be interconnected

and the connections shall be. . .

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FINAL BALLOT: 8 YES

0 N O

0 A BSTAIN

2 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The revision clarifies the original intent of the provisions.

A16

I
JOINT BALLOT NUMBER 2/14

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: P2, STF.VCTUKAL DESIGN COMMITTEE ITEM NUMBER:

ATC-3-0c SETT ION REFERENCE: 3 . 7.9

Change the second line of the third paragraph to read:

.elements of the building attached thereto plus the portion of the

seismic shear force at that level , V , required to be transferred. . .

FINAL BALLOT: 8 YES

0 NO

0 ABSTAIN

2 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The revision clarifies the original intent of the provision.

1-21

A17
JOINT BALLOT NUMBER 2/

REVIEW AN? REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL C0.4 2:ITTEE: ft 2, STRUCTURAL DESIGN COMMITTEE ITEM NUMBER: 1-23

A7C-3-06 SECTION REFERENCE: *j_2

Change the last paragraph to read as follows:

Th'e value of C may be determined in accordance with Formula 4-2, 4-3, or 4-3a, as appropriate . Formula 4-2 requires calculation of the fundamental

period of the building as specified in Sec. 4.2.2. For low buildings, or in

other instances when it is not desired to calculate the period of the

buildings , C

g shall be determined using Formula 4-3 or 4-3a, as appropriate.

FINAL BALLOT: 8 YES

0 N O

Q ABSTAIN

2 DID NOT VOTE

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COMMENT ON PROPOSED CHANGE:

The revision encourages the use of the simple equations for those situations

in which the calculation of building period has no impact on the design

force level.

A18
JOINT BALLOT NUMBER 2/1

REVIEW AN? REFINEMENT OF TENTATIVE SEISMIC PROVISION?

PROPOSED CHANGE

TECHNICAL COMMITTEE: P2, STPU CTURAL DESIGN COMMITTEE ITEM NUMBER: 1-24

AT C-3-0R SECTION REFERENCE: 4j_5

Delete the last sentence of the last paragraph.

FINAL BALLOT: _8 YES

0 NO

0 ABSTAIN

2 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The deleted sentence had potential for creating serious design problems for

those buildings using piles or piers as holddown anchors, yet no convincing

argument has been forwarded for retaining the deleted sentence.
JOINT BALLOT NUMBER

REVIEW AN? REFINEMENT OF TENTATIVE SEISMIC PROVISION?:

PROPOSED CHANGE

TECHNICAL COMMITTEE: P2

,

STRUCTURAL DESIGN COMMITTEE ITEM NUMBER : 1-25

AT C- 3-06 SECTION REFERENCE: 2.2 and 4.6.2

Change the definition of Px

to read as follows:

P^ *= the total unfactored vertical design load at and above level x.

FINAL BALLOT : 8 YES

0 N O

0 AE STAIN

2 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The original definitions for P in sections 2.2 and 4.6.2 were not identical.

The revised definition specifies the pertinent load for the investigation of

instability

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A20 I
JOINT BALLOT NUMBER 2 /IS

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROFOSED CHANGE

TECHNICAL COMMITTEE: r2, STF.LCTURAL DESIGN COMMITTEE ITEM NUMEEp.rr • 2-1

AT 0-3-06 SECTION REFERENCE: 2.1

Delete the word "wood" from the definition of SHEAR PANEL.

FINAL BALLOT: _7 YES

0 N O

_0 ABSTAIN

3 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

It is possible to design and rely on shear panels constructed from materials

other than wood, for example metal studs with gypsum board.

A21
JOINT BALLOT NUMBER 2/19

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RETIE'-.’ AN? REFINEMENT OF TENTATIVE SEISMIC PROVISIONS ^

PROPOSED CHANGE

TECHNICAL CC.'E'I TTEE : 1

' 2 , STRUCTURAL DESIGN COMMITTEE ITEM NUMBER:

ATC- 3-0 r SECTION REFERENCE: 3.3.4 (A)

Revise paragraph 3 to read as follows:

3.' A system with structural steel or cast-in-place concrete braced frames

or shear walls in which there are braced frames or shear walls so arranged that braced frames or shear walls in one plane resist no more

than the following proportion of the seismic design force in each

direction

,

including torsional effects:

a. Sixty (60) percent when the braced frames or shear walls are arranged only on the perimeter .

b . Forty (40) percent when some of the braced frames or shear

walls are arranged on the perimeter .

c . Thirty (30) percent for other arrangements .

This system is limited to 240 feet in height.

FINAL BALLOT: YES

~Q NO

0 ABSTAIN

3 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The revision explicitly recognizes the improved torsional performance of

buildings with the principal seismic resisting elements located on the

perimeter by relaxing the requirement for four independent lines of

resistance for such buildings.

A22

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JOINT BALLOT NUMBER 2/20

REVIEW ANT REFINEMENT OF TENTATIVE SEISMIC PROVISION?

PROPOSED ORANGE

TECHNICAL CORUTTEE: ft 2, STRUCTURAL DESIGN COMMITTEE ITEM NUMBER : 2-3

ATC-3-Ob SECTION KEEL REN Cl : 3.5

Revise to read as follows:

This section prescribes the minimum analysis procedure to be followed.

An alternate generally accepted procedure, including the use of an approved site specific spectrum, if desired , may be used in lieu of

the minimum applicable procedure. The limitations upon the base shear

stated in section 5.8 apply to any such analysis .

FINAL BALLOT : _7 YES

0 NO

0 ABSTAIN

3 DID NOT VOTE

COMMENT ON PROPOSED ORANGE:

The revision removes any implication that the provisions of chapter 5 constitute the only acceptable procedure for modal analysis and specifically allows the use of site specific design spectra, which is the current

state of practice for important buildings in highly seismic areas. The

precise limit on base shear given in section 5.8 is easier to understand

and apply than the limit on building period given in present wording of

section 3.5.
JOINT BALLOT NUMBER 2/21

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: /•* 2 , ST Rl CTl’KAL DE S I CN COMMITTEE ITEM NUMBER: 2-4

ATC-3-06 SECTION REFERENCE: 3^8

Revise by adding the following sentence to the end of the last paragraph

of the section:

Single story buildings in Seismic Hazard Exposure Group I that are constructed with non-brittle finishes and whose seismic resisting

system is not attached to equipment or processes need not meet the

drift requirement in table 3-C .

FINAL BALLOT: _7 YES

; _0 no

_0 ABSTAIN

_3 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

This revision is coupled with the revision proposed for table 3-6, (item

2-5 from Committee if 2) in which the footnote allowing a higher limit for

certain buildings is deleted. The types of buildings described in the

revised provision have performed well from a drift standpoint in past

earthquakes

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A24
JOINT BALLOT NUMBER 2/22

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: /-2, STRUCTURAL DESIGN COMMITTEE ITEM NUMBER: 2-5

ATC-3-06 SECTION REVERENCE : Table 3-C

Remove the footnote from the table and revise the table to read:

TABLE 3-C

ALLOWABLE STORY DRIFT A

A

a

Seismic Hazard Exposure Group

III II I

0. 015h

sx

0. 025h

sx

0. 025h

sx

FINAL BALLOT: YES

_j NO

0 ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The drift limitations of Sec. 3.8 of ATC 3-06 are, for many

structures, considerably more restrictive than the UBC and

usual current design practice. Because of the lack of a close relationship between story drift and either the amount

of inelastic strain or the mamitude of the P-delta problems,

and because damage control unrelated to safety is not a code

objective, the drift limits have been increased.

The revised values were chosen to minimize the possibility

of imposing drift constraints more severe than those reflected

in current design practice. In specific instances, however,

such as for controlling the magnitude of relative movements

at joints, the designer may find it necessary or desirable

to impose more restrictive limits.

A25
JOINT BALLOT NUMBER 2/23

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: 12, STRUCTURAL DESIGN

ATC-3-06 SECTION REFERENCE: 4.6.2

COMMITTEE ITEM NUMBER: 2-6

Revise the second sentence of the last paragraph to read as follows:

The design story drift determined in Section 4.6.1 shall be multiplied

by the factor . 0.9 > n

. to obtain the story drift including P-delta

4-e = 1,u;

effects.

FINAL BALLOT: _7 YES

_0 NO

_0 ABSTAIN

_3 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The revision explicitly defines for design use the increase in story drift

due to P-delta, and by means of introducing the approximation (0.9 = 1.0),

it avoids a troublesome discontinuity that would occur when G = 0.10.

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A26
JOINT BALLOT NUMBER 2/24

REVIEW ANT REFINEMENT OF TENTATIVE SEIS^C PROVISIONS

PROPOSED AUDITION TO COMMENTARY

TECHNICAL C0MITT7EE : P2 , S TRU CTURAL DESIGN COMMITTEE ITEM NUMBER: C-\

ATC- 3-06 SECTION REFERENCE: 3.5, ANALYSIS PROCEDURES

Insert following the fourth prargraph on page 342:

"It is possible with presently available computer programs to

perform two dimensional inelastic analyses of reasonably

symmetric structures. The intent of such analyses could be

to estimate the sequence in which components become inelastic

and to indicate those components requiring strength adjustments

so as to remain within the required dectility limits. It

should be emphasized that with the present state-of-the-art in

inelastic analysis there is no one method that can be applied

to all types of buildings, and further the reliability of the

analytical results are sensitive to:

1. the number and appropriateness of the timehistories of input motion

2. the practical limitations of mathematical modelling

including interacting effects of nonstructural

elements

3. the nonlinear algorithms

4. the assumed hysteretic behavior

Because of these sensitivities and limitations the maximum base

shear produced in the inelastic analysis should be not less

than that required by chapter 5 (Model Analysis)."

A27
JOINT BALLOT NUMBER 2/25

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REVIEW AN? REFINEMENT OF TENTATIVE SEISMIC PROVISIONS ^

PROPOSED ADDITION TO COMMENTARY

TM

TE CKN I CAL COMIC: TTEE : ft 2 , S T RU CTU KAL DE 5 1 CN COMMITTEE ITEM NUMBER: C-2.

^ ATC- 3-06 SECTION REFERENCE:

^. 1 r CLASS! FT CAT TON OF FRAMMING SYSTEMS

I

A large table of framing svstems is to be inserted in the commentarv with an ^

indication of where each system would fall in table 3-B

Secretariat’s note: the tables furnished by Henry Degenkolb and distributed

to the committee with the minutes of the Phoenix meeting are the starting point

for this item. It was my understanding that Rol Sharpe was to produce the

finished table.

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A28
JOINT BALLOT NUMBER 2/26

REVIEW ANT REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED ADDITION TO COMMENTARY

TECHNICAL COM'TTTEE : ft 2, STRUCTURAL DESIGN COMMITTEE ITEM NUMBER: C-3.

ATC- 3-06 SECTION REFERENCE: 4.6, DRIFT DETERMINATION AND P-DELTA EFFECTS

The last Daragraoh on page 368 should be considered as a part of the acceptable

P-delta analvsis referred to on page 367.

A29

lu (
JOINT BALLOT NUMBER 2/27

REVIEW ANT REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED ADDITION TO COMMENTARY

TECHNICAL COMMITTEE: f2, STRUCTURAL DESIGN COMMITTEE ITEM NUMBER: C-4

ATC- 3-06 SECTION REFERENCE: 5.5, MODAL BASE SHEAR

A plot should be included in the commentary to illustrate the pattern of spectral

coefficients for R and Av

.

Secretariat's note: It is mv understanding that Rol Sharpe will provide such a plot.

I

I

I

I

I

I

I

I

I

I

I

I

I

I

I

1

A30
COMMITTEE 3

A31
JOINT BALLOT NUMBER 3/1

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: #3, FOUNDATIONS COMMITTEE ITEM NUMBER: _le

ATC-3-06 SECTION REFERENCE: 3.2.1

The last paragraph in Section 3.2.1 should be changed to read "In

locations where the soil properties are not known in sufficient detail to

determine the soil profile type or where the profile does not fit any of

the three types, Soil Profile S£ or Soil Profile S^ shall be used depending

on whichever soil profile type results in the higher value of seismic

coefficient, C c> as determined in Section 4.2.1 .

FINAL BALLOT: 4 YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

Soil Profile Type S

2 is much better than Type S

3

. Section 3.2.1

suggests soil profile type S

2 when the soil properties are not known.

This did not seem logical. Hence the proposed change was recommended
JOINT BALLOT NUMBER 3/2

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: #3, FOUNDATIONS COMMITTEE ITEM NUMBER: 4e

ATC-3-06 SECTION REFERENCE: 7.2.2

The last sentence in Section 7.2.2 should read "For the load combination

including earthquake as specified in Section 3.7, the soil capacities must

be sufficient to resist loads at acceptable strains considering both the

short time of loading and the dynamic properties of the soil.

FINAL BALLOT: 4 YES

NO

ABSTAIN — DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

Soils are inherently inelastic materials. To specify stressing below

the elastic limit is practically without meaning. Hence, the term "elastic

limit" should be replaced with the phrase, "to resist loads at acceptable

strains” .

A33
JOINT BALLOT NUMBER 3/3

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: 13, FOUNDATIONS COMMITTEE ITEM NUMBER: 7e

ATC-3-06 SECTION REFERENCE: 7.5.2

The first sentence in Section 7.5.2 should be changed to read "Individual

spread footings unless founded directly on rock, as defined in Section 3. 2. 1(1) , shall be interconnected by ties". ~

FINAL BALLOT: 4 YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The comment was made that it is overly conservative to require structural

ties between pile caps equal to 25% of the maximum vertical load for a Category B structure. This conservatism is amplified in the commentary of this

paragraph where it states, "Lateral soil pressure on pile caps is not a re- commended method; and if the soil is soft enough to require ties, little

reliance can be placed on soft-soil passive pressure to restrain relative

displacement under dynamic conditions." There are many cases in which the use of piles is dictated by deep soil deposits and the near surface materials

are relatively stiff and strong (such as compact or dense gravels and sands

overlying soft clays or controlled, compacted fill over clays or organic

soils. In these cases, it would seem reasonable to permit at least a portion

of the lateral tie resistance between the pile caps to be provided by lateral

soil resistance with some guidance provided. In light of these considerations

and after discussing the terminology that would be appropriate, the committee

agreed to recommend the change shown above.

A34
JOINT COMMITTEE NUMBER 3/4

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: #3, FOUNDATIONS COMMITTEE ITEM NUMBER: 9e

ATC^-3-06 SECTION REFERENCE: 7.4.4

i At the end of paragraph 2 of Section 7.4.4 (before Item A) the following

sentence should be added, "Where special reinforcement at the top of the pile

is required alternative measures for containing concrete and maintaining

ductility will be permitted provided due consideration is given to forcing

the hinge to occur in the contained section.

FINAL BALLOT: 4 YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

© The committee discussed possible designs for the connection at the top

of the pile. It was agreed that the intent was to put the ductile section

where the hinge would form. Considering this fact and the comments received,

the proposed change was recommended. The minority view as expressed in a comment from Committee 4 to use an exposed strand was rejected by the

committee because it was judged that one could not manufacturer a ductile

connection between the pile and the pile cap using steel strand. Furthermore, it is at the point where the pile is connected to the pile cap that

the greatest damage was observed during the San Fernando and Alaskan earthquakes .

A35
JOINT BALLOT NUMBER 3/5

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: § 3, FOUNDATIONS COMMITTEE ITEM NUMBER: lOe

ATC-3-06 SECTION REFERENCE: 7.5.3(c) of)

' The last sentence In Section 7.5.3(c) should be revised to read, "Precast

concrete and prestressed concrete piling shall be designed to withstand maximum imposed curvatures resulting from a dynamic analysis of the soil profile."

FINAL BALLOT: 4 YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The basis for the proposed change was that prestressed precast concrete

piling can withstand considerable curvature and through proper detailing

confinement and ductility can be provided.

A36
JOINT BALLOT NUMBER 3/6

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: #3, FOUNDATIONS COMMITTEE ITEM NUMBER: 12e

ATC-3-06 SECTION REFERENCE: Chapter 6

Chapter 6 should be deleted.

FINAL BALLOT: 4 YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

After reviewing Chapter 6 and thoroughly examining the procedures therein,

the committee felt strongly that the provisions were not effective in implementing a new concept. Chapter 6 is too complicated for the practicing engineer and it is not justified based on field observations. The sophistication

of the analysis is inconsistent with the accuracy of the results and the complexity masks the understanding of the performance of the soil structure

system. Further documentation for deletion of Chapter 6 is provided in the

minutes for the February 15, 1980 meeting (attachments).

A3 7
COMMITTEE 4

A38
JOINT BALLOT NUMBER 4/1

REVIEa and RE r INE"ENT Q

r TENTATIVE SEISMIC PROVISION:

propose: chanc-e

‘ECHNICA. CO"" COMMITTEE ITEM NJ"5EATC-3-06 SEC . ION REFERENCE: .6.3(A)

Alter the sentence under EXCEPTION to read as follows:

Certified mill tests may be accepted for ASTM A706 and, where no welding is required, for ASTM A6I5 reinforcing steel.

r

I NA_ BALLOT: 8 YES

0 NO

0 ABSTAIN

0 DID NOT VOTE

COMMENT ON PROPOSED CHANC-E:

AC I 318, Appendix A permits ASTM A6 I 5 Grades 40 and 60 rei nforcemenr. vU I!

-f-gsts specify actual yield and tensi le strengths.

A39
JOINT BALLOT NUMBER 4/2

RE\ I Ea AND R£-1NE‘*E\T O

r TENTATIVE SEISMIC -ROVISIQ’

PROPOSED CHANCE

ATC-3-Cc SECTION REFERENCE: Chapter I, Table I -B

Assign a Seismicity Index of I to Map Area Number 2 and carefully review Mao

Area Number 3 to determine whether or not certain areas such as New York City

should more appropriately be designated as Map Area Number 2 for concrete

construct i on

ABSTAIN

DID NOT VOTE

,-N Z-' . — . — '-N K I D r"' ' A * 1 ~ ~

w — » • N x w w Z. ort .“A IN j* d I

The seismicity indices were introduced as a device to relate the seven mao areas

(acce I erat ion intensities) wifh the various levels of detailing requ i remenrs

,

as classified in the four seismic performance categories (A, 3, C, ana D). The

indices and the performance categories have been apparently arbitrarily inmerrelaTed with the seismic hazard exposure groups CTaPle l-A).

While there is little question about detailing retirements for the highesr

seismicity (4), and for the lowest seismicity (I), detailing requiremenrs ~or seismicity index levels of 2 and 3 remain a gray area witnout adequate background

i nformaT i on

OVER

A40
COMMENT ON PROPOSED CHANGE (continued):

Buildings located in the map areas I and 2, subjected to acceleration levels of

0.05, will undoubtedly always remain in the elastic range, requiring no additional

ductility aetails. The acceleration level of 0.10 (map area 3) wi IIin all

proDability, create an elastic response in buildings designed in conformity

with modern reinforced concrete and steel codes. It should also be considered

that current codes (i.e., ACI 318) basically result in ductile members, as provisions over the last 20 years have been devised to eliminate brittleness.

To -suddenly require additional detailing (also adding 30* of forces in perpendicular direction) in cities like New York and Chicago, based largely on judgment, not necessarily supported by adequate background studies, seems

ques+ ionab I e. Seismic code writers bear the responsibility to substantiate

the need for any restrictive changes made to codes which have been developed

in a consensus process over the last several decades. It is not for industries

to prove that such changes are unnecessary and will increase the cost of

buildings without adding to their safety.

t

A41
JOINT BALLOT NUMBER 4/3

REVIEW AND REHNEMENT QF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: £4, Concrete COMMITTEE ITEM NUMB

3 : M8

ATC-3-06 SECTION REFERENCE: 3.7.12

DeleTe The third sentence.

PINAL BALlCT: 8 YES

0 NO

0 ABSTAIN

0 DID NOT VOTE

welded steel column splices or

materials, systems, and connections.”

can have a brittle failure is consislong span extruded precast prestressed

COMMENT ON PROPOSED CHANGE:

Formula 3-2a is "for partial penetration

for reinforced masonry and ot£er brittle

The implication that prestressed members

tent with the possible behavior of some

products installed without integral topping. However, where topping, properly

reinforced and bonded, is used on such units or the component is a pretensioned

or post-tensioned unit including supplementary bonded re i nforcement equal to

the ACI Code 31-8-77 specified minimums, such brittle failures do not occur

and seismic provisions can be consistent with those for reinforced concrete

units.

A42
JOINT BALLOT NUMBER 4/4

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC pROVlSiONS

PROPOSED CHANGE

TECHNICAL COmvitTEE: Concrete COMMITTEE ITEM NUMBER: B6( I )

ATC-3-06 SECTION REFERENCE: 7 ’ 4 * 4

At the end of the first sentence, second paragraph, add the following sentence:

The pile cap connection may be made by the use of field-placed

dowels anchored in the concrete pile.

_0 NO

_0 ABSTAIN

_0 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

This is the presently accepted -practice in UBC-79 and CAL-TRANS specifications.

A43
JOINT BALLOT NUMBER 4/5

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

pRQPCSEO CHANGE

TECHNICAL COMMITTEE: #4. Concrete COMMITTEE ITEM NUMBER: 66(2)

ATC-3-06 SECTION REFERENCE: 7.4.4(E)

Add The following sentence at the end of paragraph:

The pile cap connection for Categorv B structures may also be

made by developing exposed strand.

iL wALLO i : 8 YES

0 NO

Q AESTAIN

0 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

This is the presently accepted practice in UBC-79 and CAL-TRANS specifications.

/*

A44
JOINT BALLOT NUMBER 4/6

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: Coccrexe COMMITTEE ITEM NUMBER:

ATC-3-06 SECTION REFERENCE: 7.5 and 7.6

Make the following changes:

(a) Delete Section 7.6.

(b) Alter the title of Section 7.5 to read as fol lows:

SEISMIC PERFORMANCE CATEGORIES C AND D.

(c) Alter the first sentence in Section 7.5 to read as fellows:

Buildings classified as Category C or D shall

conform to a I I of the requirements for Category B

construction except as modified in this Section.

r I NA L 5A L LOT

6 YES

2 NO

0 ABSTAIN

0 DID NOT VOTE

COMMENT ON DR0POSED CHANGE:

The use of prestressed concrete piling should not be precluded in seismic

categories C and D. Performance requirements should be given for their

design. See Committee Item Number MIO.

A45
JOINT BALLOT NUMBER 4/7

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICA_ CO*"'!TTEZ: #4, Concrete COMMITTEE ITEM NUMBER: Ml Q

ATC-3-06 SECTION REFERENCE: 7.5.3

Insert the following in Section 7.5.3:

(E) PRFCAST-PRESTRESSED PILES

(1) For the body of fully embedded foundation piling subjected to

vertical loads only, or where the design bending moment does not

exceed 0.20 Mnb ^ where Mn b is the unfactored ultimate moment capacity

at balanced strain conditions as defined in Reference II. I, Section 10.3.2),

spiral reinforcing shall be provided such that p s > 0.006 ( 0 . 2%).

(2) For free standing piling and hollow core or marine piling subject

to severe installation and operational forces, spiral reinforcing shall

be provided such that p s

> 0.022 (0.7$), or a spacing satisfying the

following relationship, if it results in a percentage of spiral greater

than that given above:

f A

S = y sp

H (C + 7 d

b

) f r

OVER

~ I NA U oALlOT : 7 YES

I NO

0 ABSTAIN

0 D I D NOT VOTE

COMMENT ON PROPOSED CHANGE:

The use of prestressed concrete piling should not be precluded in seismic

categories C and D; performance requirements should be given for their design.

References

1. Gerwick & Brauner - Design of H i qh-Performance Prestressed Concrete

Piles for Dynamic Loading (ASTM STP 670, 1979).

2. Margason - Pile Bending During Earthquakes , lecture series at U.C.

Berkeley on Effects of Ground Shaking and Movement on Piles,

March 6, 1975.

OVER

A46
ATC-3-06 SECTION REFERENCE: 7.5.3 (cm+: rvuedi

where

P s

= spacing of spiral reinforcing

= yield strength of spiral reinforcing

= area of spiral reinforcing

= cover over the spiral reinforcing

= diameter of spiral reinforcing

= modulus of rupture of concrete

= ratio of volume of spiral reinforcing to total

volume of core (out-to-out of spirals) and noi

less than that given in Section 11.7.2 (C).

(3) Any piling installed in layered soils imposing severe curvatures

during earthquake shall have the same amount of spiral reinforcing

indicated in item (2) above, accompanied by additional amounts of

flexural reinforcing indicated by moment-curvature relationships

developed for the pile and soil profile present.

(4) The top and bottom portion of hollow core piling and rigid

frame piling where high values of shear and moment occur simultaneously

should contain spiral reinforcing with p s

> 0.031 (1.0$) for a distance

of 2 pile diameter, or 2 times the width of the pile.

COMMENT ON PROPOSED CHANGE (continued):

3. Bertero, Lin, Seed, Gerwick, Brauner, and Fotinos - A Seismic Des i cn of Prestressed Concrete Piling , FIP Congress NYC, May 25, 1974.

4. Margason - Earthquake Effects on Embedded Pile Foundations , paper

presented at Pile talk Seminar, San Francisco, March, 1977.

5. Test data from dynamic cyclic prestressed piling tests conducted

under the sponsorship of the Prestressed Concrete Manufacturers

Association of California.

6. Test data from tests conducted by H. Makita of the Tokyu Concrete

Pile Company.

A47
JOINT BALLOT NUMBER 4/3

REVIEW AND REFINEMENT QF TENTATIVE SEISMIC 3p 0vlSIQNS

PROPOSE? CHANZ-E

ECHN I CA _ CO COM'.

1

! 'EM Nl'MBE- 32. ATC-3-06 SEC"!" I ON REFERENCE: 8.2.2

Ada the following sentence immediately after the definition of P and just

prior to EXCEPTIONS:

The force, F , shall be applied independently vertically,

longitudinally and laterally in combination with the static

load of the element.

8 YES

0 no

0 ActTA I

0 CIO NOT '.GTE

;ANCE :

U3C-79: The effect of vertical acceleration should pe included in the design

of nonstructura I components art*d systems.
JOINT BALLOT NUMBER 4/9

REVIEW AND RE r I NE^ENT QF TENTATIVE SEISMIC PROVISIONS

PRGPQSEO CHANGE

TECHNICS r* *si •• • » —r*- z . wv.*• f i i Z. Z . COMMITTEE ITEM NUMBER: 38

ATC-3-Cc SECTION REFERENCE: Chapter 8, Table 3-3 _____

Immediately following "Wall Attachments" and indented therefrom, insert

"Connector Fasteners" with a corresponding C c Factor of 6.0.

7 YES

0 ABSTA I

0 0 ! C NOT VOTE

COV'ENT ON PROPOSES CHANGE

Current practice as outlined in UBC-79.
JOINT BALLOT NUMBER 4/ 10

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC P pO\ISIO.NS

PROPOSED APE IT! ON TO COMMENTARY

TECHNICAL CO'-*' ' : TTEE : »4, Concrete CC‘" ' ! ~EE ITEM NUM=EC

: _M6

ATC-3-06 SECTION RE r ERENCE : 3.6.3

Alter eighth paragraph, starting with the eighth sentence so as to read:

The loading is cyclical, so static ultimate load capacities may

not be reached. If the comb i nation. . .with the values given in

Table 3-B. In the example of the flat plate warehouse, the

connections can still carry the design gravity loadings if they

satisfy the requirements of Section 11.4.1.

. “ _ rhuLJ 8 ' yt[3

0 NO

0 ABSTA I

0 DIC NOT v'C i E

C0—EN~ ON DR0p 0SED CHANCE:

Clarification of wording is required to make it consistent with the revised

Chapter II. t

A50
JOINT BALLOT NUMBER 4/ II

RE . ! EV. AND REFINEMENT 0

r TENTATIVE SEISMIC 9^0; I SIGNS

PROPC SEC ADC IT ION TQ COMMENTARY

TECHNICAL C0? *‘ ’'"EE: ?4 , Concrete COMMITTEE ITEM NUMBER: _M

ATC-3-0d SECTION RE r ERENCE: 3.7.2

Add the following sentence to the second paragrapn:

For two-way slabs orthogonal effects at s I ab-to-co I umn connections

can be neglected provided the moment transferred in the minor

direction does not exceed 30 percent of that transferred in the

orthogonal direction and there is adequate re i nforcement within

lines one and one-naif times the slab thickness either side o*

the column to transfer all the minor direction moment.

Considerable simplification that is predictable using beam-analogy

concepts (1,2) and has been proven by testing (2).

1. Hawkins, N.M., Mithcell D. and Symonds, D.W., "HystereTic Behavior of

Concrete SlaD to Column Connections," Proc. 6th World Cent. Eartnquake

Engrg., New Delhi, India, 1977.

2. Hawkins, N.M., "Seismic Resoonse of Concrete Flat Plate Structures,"

Proc. Seventh 'Wor I d Conference on Earmhauake Engrg., Instanbul, I93C.

A51
JOINT BALLOT NUMBER

see attachment

4 /

R^V I E'a AND RE r INEM ENT pr TENTATIVE SEISMIC 3 RQV 1

IONS

PROPOSED CHANGE

TECHNICAL CC^'ITTEE: Concrete COMMITTEE ITEM NUMBER: Yl

ATC-3-Cc SECTION REFERENCE: Chapter II and COMMENTARY

Revise Chapter II and Commentary Chapter II of ATC 3-06 to read as per

28 May 1980 proposal, as modified in meeting of 4 June 1980, and cnanges

necessary to incorporate those revisions into the remainder of ATC 3-06.

YES

NO

A 3S T A I N DID NOT VOTE

Chapter II is revised to reference the nationally recognized design standard,

ANSI /AC I 318-77 "Building Code Requirements for Reinforced Concrete” for

proportion i ng and detailing concrete structures. Seismic resistance is

considered in the overall development of the AC I 318 Standard, including

Appendix A on special provisions for earthquake resistance.

Existing Chapter II originated from an early draft of a proposal by an AC I 318 Seismic Subcommittee to update the AC I 318 seismic design provisions.

The current draft of ApDendix A (19 March 1980) now before the Main Committee 318

has undergone numerous revisions. Final Committee action and full AC I consensus

balloting is in process.

The revised Chapter II is formulated to correlate appropriate ACI 313 design

provisions with the four ATC seismic performance categories by reference only

without the need for ATC to duplicate the wording already contained in the

ACI document.

A CO
June 4, 1980

CHAPTER 11 - Pages 101-110

REVISE CHAPTER 11 TO READ AS FOLLOWS:

CHAPTER 11

REINFORCED CONCRETE

Sec. 11.1 - REFERENCE DOCUMENTS

The quality and testing of concrete and steel materials and the design and

construction of reinforced concrete components that resist seismic forces

shall conform to the requirements of the references listed in this Section,

except as modified by the provisions of this Chapter.

Ref. 11.1 ANSI/ACI 318-77 "Building Code Requirements for Reinforced

Concrete" including proposed revision Appendix A* - "Requirements

for Reinforced Concrete Building Structures Resisting Forces induced by Earthquake Motions" dated 19 March 1980, American

Concrete Institute.

Ref. 11.2 AWS Dl. 4—79 "Structural Welding Code - Reinforcing Steel" American

Welding Society.

Sec. 11.2 - REQUIRED STRENGTH

Required strength to resist seismic forces determined by analysis procedures

of Chapter 4 or 5 shall be in accordance with Sec. 3.7.1 in lieu of ACI 313

Section 9.2.3.

Sec. 11.3 - SEISMIC PERFORMANCE CATEGORY A

Buildings assigned to Category A may be of any construction permitted by ACI

318, and shall conform to the minimum requirements of ACI 318, excluding

Appendix A.

All welding of reinforcement shall conform to Ref. 11.2.

* "Appendix A-Requirements for Reinforced Concrete Building Structures

Resisting Forces induced by Earthquake Motions," 19 March, 1980;

copy attached.

A53
Anchor bolts at tops of columns and similar locations shall be closely

enclosed within not less than two #4 or three #3 ties located within

4 inches from top of columns. Allowable loads on anchor bolts shall not

exceed those given in Table 11 -A

Sec. 11.4 - SEISMIC PERFORMANCE CATEGORY B Buildings assigned to Category B shall conform to all the requi reTents for

Category A and to the additional requirements of this Section.

11.4.1 - ORDINARY MOMENT FRAMES

Where ordinary moment frames are used for the seismic resisting system,

frame components (beams and columns) shall be proportioned to satisfy the

additional provisions of ACI 318, Appendix A. 3. 2, A. 3. 3, A. 4. 3, and A. 8. 2.

(See ACI 318 Appendix A. 2. 1.3).

EXCEPTION:

Where slab systems without beams between supports and supported on columns are used for the seismic resisting system, the following

provisions shall apply to slab components in lieu of ACI 313,

Appendix A. 3. 2 and A. 3. 3.

(A) Area of bottom slab reinforcement not less than 1.3 V^/ $f

shall be provided continuous through or anchored within

column supports, where is factored shear force transferred

to supporting columns due to gravity loading only. Shear force

may be reduced by vertical component of effective prestress

force for slab systems with prestressing tendons continuous

through or anchored within supporting columns.

(B) In each direction, at least 2 bars shall be provided in both

top and bottom of slab and made continuous through or anchored

within supporting columns.

(C) At least 60 percent of column strip negative moment reinforcement shall be concentrated between lines that are one and

one-half slab thickness (1.5h) outside opposite faces of columns.

A54
(D) Shear strength of slab at slab-column connections shall not

be taken greater than (1 + 4/8

c )/fJbQ

d when subject to shear

force V

u

, where b

Q

is perimeter of a critical section perpendicular to plane of slab and located so that its perimeter is a minimum, but need not approach closer than d/2 to perimeter of

supporting column.

(E) At discontinuous edges of slabs without an edge beam, reinforcement within a distance 4h on either side of a supporting

column shall be detailed to resist torsic" at discontinuous

edges.

11.4.2 - FRAMING SYSTEMS

All components of the seismic resisting system (moment frames,

structural walls, braced frames, and diaphragms) shall be

proportioned in accordance with provisions of ACI 313, Appendix

A. 2.1.

EXCEPTION:

Seismic resisting framing systems not satisfying the requirements

of Sec. 11.4.1 may be used if it is demonstrated by experimental

evidence and analysis that a proposed system will have strength,

stiffness, stability, durability, and energy dissipation

capacity equal to or exceeding that provided by a comparable

monolithic cast-in-place framing system satisfying Sec. 11.4.1.

Alternatively, seismic resisting framing systems that do not

contain required special details or energy dissipating

mechanisms may be used if designed for forces determined by the

analysis procedures of Chapters 4 or 5 with an R value of 1.5.

Sec. 11.5 - SEISMIC PERFORMANCE CATEGORY C AND D

3uildings assigned to Categories C and D shall conform to all the

requirements for Category B and to the additional requirements of this

Section.

A55
11.5.1 - MATERIAL REQUIREMENTS

Materials used in the components of the seismic resisting system shall

conform to ACT 318, Appendix A. 2. 4 and A. 2. 5.

11.5.2 - FRAMING SYSTEMS

All components of the seismic resisting system (moment frames, structural

walls, braced frames, and diaphragms) shall be proportioned in accordance

' I with provisions of ACI 318, Appendix A.

. EXCEPTION:

Seismic resisting framing systems not satisfying the requirements of ACI 318, Appendix A, may be used if it is demonstrated

by experimental evidence and analysis that a proposed system

will have strength, stiffness, stability, durability, and

energy dissipation capacity equal to or exceeding that provided

by a comparable monolithic cast-in-place framing system

satisfying Appendix 'A.

Alternatively, seismic resisting framing systems that do not

contain required special details or energy dissipating mechanisms may be used if designed for forces determined by the

analysis procedures of Chapters 4 or 5 with an R value of 1.5.

11.5.3 - STRUCTURAL DIAPHRAGMS

Cast-in-place topping on precast floor systems may serve as structural

diaphragms to transmit inertia forces to seismic resisting elements provided

the cast-in-place topping is proportioned and detailed to resist the shear

forces under the effects of any loading combination (which could induce

tensile or compressive stresses simultaneously to the shear forces). Alternate techniques based on the use of untopped precast and/or prestressed

components of concrete floor systems may be used only if shown by test and

analysis based on established engineering principles that the floor systems

will provide the same strength, stiffness, stability, durability and sufficient energy dissipation capacity as a monolithic cast-in-place ordinary

reinforced concrete diaphragm.

A56
11.5.4 - FRAME COMPONENTS NOT PART OF SEISMIC RESISTING SYSTEM

All frame components assumed to be not part of the seismic resisting system

shall have demonstrated capabilities satisfying Sec. 3.3.4(c) and shall

conform to the requirements of ACI 318, Appendix A. 3; except, the lateral

deformation requirement of A. 8.1 shall not apply. If nonlinear behavior is

required in such components to comply with Sec. 3.3.4(c), the critical

portions shall be provided with special transverse reinforcement in

accordance with ACI 318, Appendix A. 3. 3 or A. 4. 4.

11.5.5 - RELATIVE FLEXURAL STRENGTH OF COLUMNS

In lieu of ACI 318, Appendix A. 4. 2, the following shall apply for relative

strength of columns.

At any joint where the framing columns resist a factored axial compressive

force larger than (A f^/10), the moment in the plane of the frame considered and about the center of the joint corresponding to the flexural

strengths of the columns or column shall exceed that corresponding to the

flexural strengths of the beams framing into the joint. If this requirement

is not satisfied for certain beam-column connections, the remaining columns

in the building frame and connected flexural members shall comply and shall

be capable of resisting the entire shear at that level accounting for the

altered relative rigidities and torsion resulting from the omission of

elastic action of the nonconforming beam-column connections. In addition,

the columns framing into the affected joint shall be provided with special

lateral reinforcement as specified in ACI 318, Appendix A. 4. 4 throughout

their entire story height. Column flexural strengths shall be calculated for

the most critical axial design force consistent with the direction of the

seismic forces considered.
TABLE 11 -A

ALLOWABLE SHEAR AND TENSION ON BOLTS1

DIAMETER

MINIMUM ~ EMBEDMENT^ SHEAR TENSION

( inches) ( inches) ( lbs) ( lbs.

)

1/4 2% 500 360

3/8 3 1100 900

1/2 4 1900 1700

5/8 G

J 3000 2700

3/4 Sh 4300 4050

7/8 6 5900 5750

1 7 7700 7500

^Values shown are for minimum concrete compressive strength

of 3000 psi at 28 days.

Values are for natural stone aggregate concrete and bolts

of at least A-307 quality. Bolts shall have a standard

bolt head or equal deformity in the embedded portion.

Values are based upon a bolt spacing of 12 diameters with

a minimum edge distance of 6 diameters. Such spacing and

edge distance may be reduced 50 percent with an equal

reduction in value. Use linear interpolation for intermediate spacings and edge margins.

2

A minimum embedment of 9 bolt diameters shall be provided

for anchor bolts located in the top of columns for buildings located in Seismicity Index Areas 3 and 4.

A58
COMMENTARY CHAPTER 11 - Pages 449-459

REVISE COMMENTARY CHAPTER 11 TO READ AS FOLLOWS:

COMMENTARY

CHAPTER 11: REINFORCED CONCRETE

For the proper detailing of reinforced concrete construction for earthquake resistance, design standard ANSI/ACI 318-77 "Building Code Requirements for Reinforced Concrete" is referenced. Seismic resistance is

considered in the overall development of the ACI 318 Standard, including an Appendix A on Special Provisions for Reinforced Concrete Building Structures

to Resist Forces Induced by Earthquake Motions.

Chapter 11 is formulated to reference appropriate ACI 318 design provisions

within the four ATC seismic performance categories (A through D). ACI 313

Appendix A refers to zones of different seismicity (Zones 0 through 4) for

application of the special provisions for seismic design. For application

of Appendix A within- the ATC Seismic performance categories, buildings

assigned to ATC Category A are interpreted as located in Zone 0 or 1 (regions of no or minor seismic risk), requiring no special provisions for

seismic design. Buildings assigned to ATC Category B are interpreted as located in Zone 2 (regions of moderate seismic risk) per Appendix A. 2. 1.3.

Buildings assigned to ATC Category C and D are interpreted as located in

Zones 3 and 4 (regions of high seismic risk), per Appendix A. 2. 1.4. The

proporti oning and detailing requirements for frames and walls resisting

seismic forces are suimiarized as follows:

For buildings in seismic performance category A, no special provisions are required; the general requirements of ACI 318-77 apply for proportioning and

detailing concrete structures.

The code sections cited in ACI 318, Appendix A. 2. 1.3 for ordinary moment

frames (beam-column framing systems) in seismic performance Category 3

Frame

Wall

Category A Category B ACI 318-77 Appendix A. 2. 1.3

ACI 318-77 ACI 318-77

Categories C & D Appendix A

Appendix A

A59
govern reinforcement details of the beam and column components as follows:

For slab systems without beams between column supports, the slab components

of the frame are detailed in accordance with the special EXCEPTION provisions

of Sec. 11.4.1.

There are no special requirements for other structural or nonstructural

components of buildings in Category B.

In regions of high seismic risk (Categories C and D), the entire building,

including the foundation and nonstructural elements, must satisfy ACI 313

Appendix A.

It should be noted that a structural system in a higher category (D being

higher than A) must satisfy the requirements specified for the lower categories: A structural frame which forms part of the seismic resisting system

of a Category C building must satisfy all of the frame requirements of ACI

313 Appendix A, including Appendix A. 2. 1.3.

Sec. 11.2 - REQUIRED STRENGTH

Calculations to determine the strength of structural comoonents and members

are to be based on Ref. 11.1; except, the factored loads and load combinations to resist seismic forces must be in accordance with Sec. 3.7.1 in lieu

of ACI 318 Section 9.2.3. This exception is necessary so that the required

strength for seismic resistance. Sec. 3.7.1, is compatible with the design

forces specified in Chapter 3.

Sec. 11.3 - SEISMIC PERFORMANCE CATEGORY A

Construction qualifying under Category A as identified in Table 1-A (Chapter

1) may be built with no special detail requirements for earthquake resistance

except for ties around anchor bolts as indicated in Sec. 11.3. "Closely

enclosed" is intended to mean that the ties should be located within 3 to 4

bolt diameters of the bolts.

Longitudinal reinf orcement

Transverse reinforcement

Beams

A. 3.

A. 3.

Columns

A. 4.

A. 3.

A60
Sec. 11.4 - SEISMIC PERFORMANCE CATEGORY B A frame used as part of the lateral force resisting system in Category B as identified in Table 3-B is required to have certain details which are intended to help sustain integrity of the frame when subjected to deformation reversals into the nonlinear range of response.

For beam and column framing systems, the reinforcement details of ACI 318

Appendix A. 3. 2 and A. 3. 3 apply for beam components and A. 4. 3 and A. 8. 2 apply

for column components.

For slab and column framing systems, the slab component must satisfy the

special EXCEPTION provisions of Sec. 11.4.1, in lieu of A. 3. 2 and A. 3. 3.

Columns must satisfy the provisions of A. 4. 3 and A .8.2. For slab-column

connections, paragraph (A) provides slab reinforcement through a column to

support the slab gravity load in the unexpected event that a punching

failure occurs. Paragraph B) specifies a minimum amount for that reinforcement. Concentration of negative moment reinforcement at the column as provided by paragraph (C), is required to create a situation whereby the

total negative moment reinforcement across the entire slab width will yield

simultaneously. Without the heavier concentration of reinforcement, the

slab region at the column will yield considerably before the outer regions

of the slab, with markedly decreased lateral load stiffness. Paragraph (D)

in effect limits the shear stress caused by gravity loads to a sufficiently

low value so that the slab-column connection will have a ductility ratio of

at least 2. Paragraph (E) ensures that if shear or torsional cracks develop

at the slab edges, properly detailed reinforcement is present to control

cracking.

As shown in Fig. A there should be top and bottom bars in the slab

paralleling and as close to the discontinuous edge as possible, continuous

through the column and enclosed within transverse reinforcement having a spacing not greater than 0.5d. The transverse reinforcement can be closed

hoops, hairpin stirrups projecting l beyond the face of the column as shown in Fig. A or slab bars bent to satisfy the requirements for hairpin.

A61
minimum projection

beyond column face,

top and bottom of slab

bottom

bar

'hairpins or bars from

slab for length 4h

minimum projection 2

03

Fig. A - Reinforcement Details

Satisfying Section 11.4.1 (E)

Structural (shear) walls of buildings in Category B are to be built in

accordance with the general requirements of ACI 318-77.

Sec. 11.5 - SEISMIC PERFORMANCE CATEGORY C AND D

In regions of high seismic risk, the entire building, including the foundation and nonstructura 1 elements, must satisfy all of the requirements of

ACI 318 Appendix A.

Appendix A contains special proportioning and reinforcement detailing

requirements which are currently considered to be the minimum for producing

a monolithic reinforced concrete structure with adequate proportions and

details to make it possible for the structure to undergo a series of

oscillations into 'the inelastic range of response without critical decay in

strength. The demand for integrity of the structure in the inelastic range

of response is consistent with the rationalization of design forces specified

in Chapter 3.

A62
Field and laboratory experience which has led to the special proportioning

and detailing requirements in ACI 318 Appendix A has been predominantly with

monolithic reinforced concrete building structures. Therefore, the projection of these requirements to other types of reinforced concrete structures,

which may differ in concept or fabrication from monolithic construction,

must be tempered by relevant physical evidence and analysis. Precast and/or

prestressed elements may be used for earthquake resistance provided it is

shown that the resulting structure will satisfy the safety and serviceability

(during and after the earthquake) levels provided by monolithic construction.

A detailed explanation of the specific provisions of ACI 318 Appendix A is

contained in the ACI Code Commentary to Appendix A.

11.5.2 - FRAMING SYSTEMS

The strength and "toughness" requirements for framing systems not satisfying

the requirements of ACI 318 Appendix A refer to the concern for the

integrity of the entire lateral-force structure at lateral displacements

anticipated for ground motions corresponding to design intensity. Depending

on the energy-dissipation characteristics of the structural system used,

e> such displacements may have to be more than those for a monolithic

reinforced concrete structure.

For systems that remain elastic or that have limited special details for

energy dissipation, such as assemblages of precast and/or prestressed

concrete, appropriate R-f actors should be used to reflect damping characteristics and energy dissipation. For example, R ^ I

s* can be used for

systems responding primarily elastically to account for damping, and R ^ up

to 2h may be used for walls with properly distributed web reinforcement that

will assure good distribution of cracks and thus provide a degree of energy

dissipation.

A63
11.5.4 - FRAME COMPONENTS NOT PART OF SEISMIC RESISTING SYSTEM

In the event of a strong earthquake, it is assumed that the structure will

undergo reversals of large lateral displacements. It is essential that all

structural components be able to acconmodate these displacements without

critical loss of strength. Even if a particular frame has been designed to

support only gravity loads and is not intended to be part of the structural

system resisting seismic forces, it must sustain the gravity loads after

having been subjected to approximately the same displacements as the seismic resisting system. Therefore, all frame components (which are not

designed to resist seismic forces) in Categories C and D buildings are reauired to have, as a minimum, the details specified in ACI 318 Appendix

A. 8. Furthermore, if calculations show that frame components (which are not

part of the structural system resisting seismic forces) will have to yield

in order to accommodate the calculated displacements of the seismic resisting system, those components must have special transverse reinforcement as specified for Special Moment Frames.

Slab systems without beams between supports (flat plates) of normal proportions and detailed as specified in Sec. 11.4.1 (EXCEPTION) will not

undergo any significant yield until story drifts greater than those

allowable. (Table 3-C).

A64

s

[
OTHER REVISIONS TO INCORPORATE NEW CHAPTER 11 - (REINFORCED CONCRETE)

INTO ATC 3-06

1. SEC. 1.6.3(B) - PAGE 32

Change reference "AC I 313-71" to "ACI 318-77"

2 . SEC. 2.1 DEFINITIONS - PAGE 37

Revise the following definitions:

CROSS-TIE is a continuous bar. No. 3 or l<n y er in size, having a 135-degree hook with a ten-diameter extension at one end and a 90-degree

hook with a six-diameter extension at the other end. The hooks shall

engage hoop bars and be secured to longitudinal bars.

HOOP is a closed tie or continuously wound tie (not smaller than No. 3

in size) the ends of which have 135-degree hooks with ten-diameter

extensions, that encloses the longitudinal reinforcement

JOINT, LATERALLY CONFINED is a joint where members frame into all four

sides of the joint and where each member width is at least three-fourths

the column width.

In definition of BRACED FRAME, add the following sentence at the end:

"In Chapter 11, reinforced concrete braced frames may be referred to as structural trusses."

In definition of ORDINARY MOMENT FRAME change reference "Sec. 11.6" to

"Sec. 11.4.1."

In definition of SPECIAL MOMENT FRAME change reference "Sec. 11.7" to

Sec. 11.5."

Add the following definitions:

A65
BOUNDARY ELEMENTS are portions along the edges of walls and diaphragms

strengthened by longitudinal and transverse reinforcement. Boundary

elements do not necessarily require an increase in the thickness of the

wall or diaphragm. Edges of openings within walls and diaphragms may

also have to be provided with boundary elements.

COLLECTOR ELEMENTS are elements which serve to transmit the inertial

forces within the diaphragms to elements of the lateral-force resisting

systems.

3. SEC. 2.2 SYMBOLS - PAGE 40

Oelete symbols A

ch>

A

sh , h c>

P n

, s h

Add the following new symbols and definitions:

b

Q = perimeter of critical section for slabs. Sec. 11.4.1

d = distance from extreme compression fiber to centroid of tension

• reinforcement. Sec. 11.4.1

f specified compressive strength of concrete, psi

f * specified yield strength of reinforcement , psi

h * overall thickness of member. Sec. 11.4.1

V

u = factored shear force due to gravity loading. Sec. 11.4.1.

# 4. TABLE 3-3 - PAGE 52

Revise footnote (4) to read as follows:

4

As defined in Sec. 11.5

5. SEC. 7.5.3(C) - PAGE 75

Change reference "Sec. 11.6.2" to "Ref. 11.1, ACI 318 Appendix

A. 8. 2"

6. SEC. 12.5.1(D) PAGE 114

Change paragraph (1) to read as follows:

"1. Ref. 11.1, ACI 318 Appendix A. 5. 3 when of reinforced concrete or Chapter 10 when of structural steel."

A66
PROPOSED REVISION TO ACI STANDARD 318-77 19 torch 1980

APPENDIX A - REQUIREMENTS FOR REINFORCED CONCRETE BUILDING STRUCTURES

RESISTING FORCES INDUCED BY EARTHQUAKE MOTIONS

A.O-Notation

A

c

= net area of concrete section resisting shear, bounded by web

thickness and section height, sq.in.

A

^

3 cross-sectional area of a structural element measured out-to-out

of transverse reinforcement, sq.in.

» area of concrete section resisting shear of an individual pier,

sq.in.

Ag 3 gross area of section, sq.in.

A

s ^

= total cross-sectional area of transverse reinforcement (including cross-ties) within spacing "s" and perpendi cul ar to dimension "h 1 '

A

v = total cross-sectional area of shear reinforcement within

spacing "s" and perpendicul ar to longitudinal axis of structural

element, sq.in.

A

vf

= total cross-sectional area of reinforcement perpendicular to a construction joint, sq.in.

b 3 effective compressive flange width of a structural element, in.

f'c 3 specified compressive strength of concrete, psi

fy 3 specified yield stress of reinforcement, psi

f^ 3 specified yield stress of transverse reinforcement , psi

h" 3 cross-sectional dimension of column core measured c-to-c of

confining re inf orcement

3 anchorage length for a bar with a standard hook as defined

in Section A.l

i 3 anchorage length for a straight bar

£ 3 minimum length, measured from joint face along axis of

structural element, over which transverse reinforcement must be

provided, in.

P. 3 minimum factored compressive force at a construction joint

(positive for compression), lb.

s 3 spacing of transverse reinf orcement measured along the longitudinal axis of the structural element, in.

s 3

3 maximum spacing of transverse reinforcement, in.

A67
V. 3 nominal shear force at a construction joint, lb.

Jy

3 dimensionless factor reflecting the influence of confinement

of a joint by structural elements framing into joint

p . 3 reinforcement ratio, ratio of nonprestressed tension reinforcement

3 area at a section to the product "bd"

P, s A /A • where A_. is the projection on A„

of total area of reinforcement crossing the plane of A^

3 reinforcement ratio on a plane perpend icul ar to A

P

$

3 ratio of volume of spiral reinforcement to the core volume

confined by the spiral reinforcement (measured out-to-out)

$ 3 strength reduction factor

A.l -Definitions

Cross -Tie - A continuous bar, No. 3 or larger in size, having a 135-degree hook with a ten-diameter extension at one end and a 90-degree hook with a six-diameter extension at the other end. The

hooks shall engage hoop bars and be secured to longitudinal bars.

Hoop - A closed tie or continuously wound tie (not smaller than No. 3

in size) the ends of which have 135-degree hooks with ten-diameter

extensions, that encloses the longitudinal reinforcement.

Structural Walls - Walls proportioned to resist combinations of shears,

moments, and axial forces induced by earthquake motions.

Structural Diaphragms - Structural elements', such as floor and roof

slabs, which transmit the inertial forces to the lateral-force

resisting elements.

Structural Trusses - Assemblages of reinforced concrete elements subjected primarily to axial forces.

Lateral-Force Resisting System - That portion of the structure ccmDosed

of elements proportioned to resist forces related to earthquake effects.

A68
Base of Structure - The level at which the earthquake motions are

assumed to be imparted to the building.

Boundary Elements - Portions along the edges of walls and diaphragms

strengthened by longitudinal and transverse reinforcement. Boundary

elements do not necessarily require an increase in the thickness of the

wall or diaphragm. Edges of openings within walls and diaphragms may

also have to be provided with boundary elements.

Collector Elements - Elements which serve to transmit the inertial

forces within the diaphragms to elements of the lateral -force resisting

systems

Anchorage Length for a 3ar with a Standard Hook - The shortest distance

between the critical section (where the strength of the bar is to be

developed) and a tangent, perpendicular to the axis of the bar

anchored, to the outer edge of the hook.

Lightweight Concrete - Concrete in which any part or all of the

aggregates ha's been replaced by lightweight material.

Shell Concrete - Concrete outside the transverse reinforcement confining the concrete.

A. 2-General Requirements

A. 2.1-Scope

A. 2. 1.1-Appendix A contains special requirements for design and

construction of reinforced concrete elements of a structure for which

the design forces, related to earthquake motions, have been determined

on the basis of energy dissipation in the nonlinear range of response.

A.2.1.2-The provisions of Chapters 1 through 17 shall apply except as modified by the provisions of Appendix A.

A69
A. 2. 1.3-In regions of moderate seismic risk*, reinforced concrete

frames resisting forces induced by earthquake motions shall be proportioned to satisfy, in addition to the requirements of Chapters 1 through 17, only Sections A. 3. 2, A. 3. 3, A. 4. 3, and A. 3. 2 of Appendix A.

A. 2. 1.4-In regions of high seismic risk**, all components of reinforced

concrete structures shall satisfy all requirements of Appendix A.

A.2.1.5-A reinforced concrete structural system not satisfying the

requirements of Appendix A may be used if it is demonstrated by

experimental evidence and analysis that the proposed system will have

strength and toughness equal to or exceeding those provided by a comparable monolithic reinforced concrete structure satisfying Appendix A.

A. 2. 2-Analysis and proportioning of structural elements

A.2.2.1-The interaction of all structural and nonstructural elements

which materially affect the linear and nonlinear response of the

structure to earthquake motions shall be considered in the analysis.

A.2.2.2-Rigid elements assumed not to be a part of the lateral force

resisting system may be used provided their effect on the resDonse of

the system is considered and accommodated in the structural design.

Consequences of failure of structural and nonstructural elements which

are not a part of the lateral -force resisting system shall also be

con si dered.

A.2.2.3-Structural elements below the base of structure required to

transmit forces resulting from lateral loads to the foundation shall

also comply with the requirements of Appendix A.

A. 2. 2. 4-All structural elements assumed not to be part of the lateral

force resisting system shall conform to Section A. 3.

*Regions falling in Zone 2 as defined by the Uniform Building Code

**Regions falling in Zones 3 and 4 as defined by the Uniform Building Code
A.2.2.5-Except as required otherwise in Appendix A, structural elements

and connections shall be proportioned to resist the load effects with

adequate strength in accordance with the provisions of this code using

the load factors and strength reduction factors specified in Chapter 9.

A. 2. 3-Strength reduction factors

Strength reduction factors shall be as given in' Chapter 9 except for

the following:

A.2.3.1-The strength reduction factor shall be 0.6 for any structural

element if its nominal shear strength is less than the shear corresponding to its nominal flexural strength for the design loading

conditions.

A.2.3.2-The strength reduction factor for axial compressive force shall

be 0.5 for all frame elements with factored axial compressive forces

exceeding5 (A_.fi/10) if the transverse reinforcement does not conform

g c to Section A. 4.

A. 2. 3. 3-Strength reduction factor for anchorage length of reinforcement shall be 0.65.

A. 2. 4-Concrete in elements resisting earthquake-induced forces

The specified 23-day compressive strength, f' of the concrete shall

be not less than 3,000 psi. The specified 23-day compressive strength,

f ' , shall not exceed 4,000 psi for lightweight concrete.

v«

A. 2. 5-Reinforcement in elements resisting earthquake-induced forces

A. 2. 5. 1-Reinforcement resisting earthquake- induced flexural and axial

forces in frame elements and in wall boundary members shall comply with

ASTM A706. AS7M A615 Grades 40 and 50 reinf orcement may be used in

these elements if (a) the actual yield stress based on mill tests does

not exceed the specified yield stress by more than 13,000 psi (retests

shall not exceed this value by more than an additional 4,000 psi) and

(b) the ratio of the actual ultimate tensile stress to the actual

tensile yield stress is not less than 1.25.

A71
A. 2. 5. 2-Splices in the reinforcement effected through welding or mechanical connections shall conform to Sections 12.15.3.1 through 12.15.3.4.

A.3-Flexural elements of frames

A. 3. 1-Scope

The requirements of this section apply to frame elements (a) resisting

earthquake- induced forces (b) proportioned primarily to resist flexure,

and (c) satisfying the following conditions:

A.3.1.1-Factored axial compressive force on the element shall not

exceed (A f'/lO).

g c

A.3.1.2-Clear span for the element shall not be less than four times

its effective depth.

A.3.1.3-The width-to-depth ratio shall not be less than 0.3.

A.3.1.4-The width shall not be less than 10 in. or more than

of the supporting element (measured on a plane perpendicular

longitudinal axis of the -flexural element) plus distances on of the supporting element not exceeding three-fourths of the

the flexural element.

the width

to the

each side

depth of

A . 3 . 2 -Lon g i t ud i na 1 re i nforcement

A. 3. 2.1 -At any section of a member subjected to bending, the reinforcement ratio, p, for the top and for the bottom reinforcement, shall not

be less than (200/f ) and shall not exceed 0.025 at any section. At

least two bars shall be provided continuously both top and bottom.

A.3.2.2-The positive-moment strength at the face of the joint shall be

not less than one-half of the negative-moment strength provided at that

face of the joint. The negative- and the positive -moment strengths at

any section along the length of the element shall not be less than

one-fourth the maximum moment strength provided at the face of either

joi nt.
A. 3. 2. 3-Lap splicing of flexural reinf orcement is permitted only if

hoop or spiral reinforcement is provided over the lap length. Maximum

spacing of the transverse reinforcement over the lap length shall not

exceed d/4 or 4 in. Lap splices shall not be used (a) within the

joints, (b) within a distance of twice the member depth and the face of

the joint, and (c) at locations where analysis indicates flexural

yielding in connectin with inelastic lateral displacements of the frame.

A.3.2.4-Welded splices and mechanical connections conforming to Sections

12.15.3.1 through 12.15.3.4 may be used for splicing provided "pt more

than alternate bars in each layer of longitudinal reinforcement are

spliced at a section and the distance between splices of adjacent bars

is 24 in. or more, measured along the longitudinal axis of the frame

element.

A.3.3-7ransverse reinforcement

A. 3. 3. 1-Hoops shall be provided in the following regions of frame

elements

(1) Over a length equal to twice the member depth measured from the

face of the supporting member toward midspan, at both ends of the

flexural member.

(2) Over lengths equal to twice the member depth on both sides of a section where flexural yielding may occur in connection with inelastic

lateral displacements of the frame.

(3) Wherever compression reinforcement is required by analysis.

A. 3. 3. 2 -The first hoop shall be located nor more than. 2 in. from the

face of a supporting member. Maximum spacing of the hoops shall not

exceed (a) d/4, (b) eight times the diameter of the smallest longitudinal bars, (c) 24 times the diameter of the hoop bars, and (d) 12 in.

A.3.3.3-Where hoops are required, longitudinal bars shall have lateral

support conforming to Section 7.10.5.3.
A.3.3.4-Where hoops are not required, stirrups shall be spaced at no more than d/2 throughout the length of the member.

A. 3. 3. 5-Hoops in flexural elements may be made up of two pieces of

re inf orcement : a stirrup having 135-degree hooks with ten-diameter

extensions anchored in the confined core and a cross-tie to make a closed hoop. Consecutive cross-ties shall have their 90-degree hooks

at opposite sides of the flexural element.

A. 4-Frame elements subjected to bending and axial load

A. 4. 1-Scope

The requirements of this section apply to frame elements (a) resisting earthquake- i nduced forces (b) having a factored axial compressive

force exceeding (A f^/10) and (c) satisfying the following conditions:

A.4.1.1-The shortest cross-sectional dimension, measured on a straight

line passing through the geometric centroid, shall not be less than

12 in.

A.4.1.2-The ratio of the shortest cross-sectional dimension to the

perpendicular dimension shall hot be less than 0.4.

A. 4. 2-Relative Strength of Columns

A. 4. 2.1 -At any joint where the framing columns resist a factored axial

compressive force larger than (A f^/10), the sum of the flexural

strengths of the columns calculated for the maximum design axial force

shall exceed the sum of the flexural strengths of the beams framing

into that joint in the same vertical plane. The flexural strengths

shall be sunmed such that the column moments oppose the beam moments,

and the check shall be made in both directions.

A.4.2.2-If Section A. 4. 2.1 is not satisfied at a joint, columns

supporting reactions from that joint shall be provided with transverse

re inf orcement as specified in Section A. 4. 4 over their full height v*

A7 4
the factored axial force in those columns, related to earthquake

effect, exceeds (A f'/10).

9 c

A.4.3-Longitudi nal reinforcement

A.4.3.1-The reinforcement ratio, P , shall not be less than 0.01 and

shall not exceed 0.06.

A. 4. 3. 2-Lap splices are permitted only within the center half of the

member span. Welded splices and mechanical connections conforming to

Sections 12.15.3.1 through 12.15.3.4 may be used for splicing the

reinforcement at any section provided not more than alternate longitudinal bars are spliced at a section and the distance between splices

is 24 in. or more, along the longitudinal axis of the reinforcement.

A.4.4-Transverse reinforcement

A.4.4.1-Transverse reinforcement as specified below shall be provided

unless a larger amount is required to resist shear by Section A. 7.

(1)

The volumetric ratio of spiral or circular hoop reinforcement , P

$ , shall not be less than that indicated by Eq. (A-l).

p

s * °- 12 f^

f

yh (A-l)

and shall not be less than that required by Eq. (10-5).

(2)

The total cross-sectional area of rectangular hoop reinforcement

shall not be less than that given by Eq. (A-2) and (A—3 )

A

sh = 0.3 (Sh-f'/f^) [(A

g

/A

c

) -1]

A

sh = 0.12 (Sh'f'/f^,)

(A-2)

(A-3)

(3)

Transverse reinforcement may be provided by single or overlapping

hoops. Cross-ties of the same size and spacing as the hoops may be

used. Each end of the cross -tie shall engage a peripheral longitudinal

A75
reinforcing bar. Consecutive cross-ties shall be alternated end-forend along the longitudinal reinforcement.

(4) If the core of the member is sufficient to resist the forces

resulting from the specified combination of dead load, live load, and

earthquake effects, compliance with Eq. (A-2) and (10-5) is not

required.

A.4.4.2-Transverse reinforcement shall be spaced at distances not

exceeding (a) one-quarter of the minimum member dimension and

(b) 4 in.

A. 4. 4. 3-Cross-ties or legs of overlapping hoops shall not be spaced

more than 14 in. on center in the direction perpendicular to the

longitudinal axis of the structural element.

A.4.4.4-Transverse reinforcement in amount specified in Section A. 4. 4.1

through A. 4. 4.3 shall be provided over a length from each joint face

and on both sides of any section where flexural yielding may occur in

connection with inelastic lateral displacements of the frame. The

length shall not be less than (a) the depth of the member at the joint

face or at the section where flexural yielding may occur, (b) one-sixth

of the clear span of the member, and (c) 13 in.

A. 4. 4. 5-Columns supporting reactions from discontinued stiff elements,

such as walls or trusses, shall be provided with transverse reinforcement as specified above over their full height beneath the level at

which the discontinuity occurs if the factored axial compressive force

in these members, related to earthquake effect, exceeds (A f^/10).

A.5-Structural Walls, diaphragms, and trusses

A. 5. 1-Scope.

The requirements of this section apply to structural walls and trusses

serving as parts of the earthquake-force resisting systems as well as

A76
to diaphragms, struts, ties, chords and collector elements which

transmit axial forces induced by earthquake. Frame elements, resisting

earthquake forces, not complying with Section A. 3 or A. 4, shall comply

with this section.

A. 5 .2-Reinforcement

A.5.2.1-The reinforcement ratio, p, for structural walls shall not be

less than 0.0025 along the longitudinal and transverse axes. Reinforcement spacing each way shall not exceed 13 in. The reinforcement

required by analysis for shear strength shall be distributed uniformly.

A.5.2.2-At least two curtains of reinforcement shall be used in a wall if

the in-plane factored shear force assigned to the wall exceeds 2A„ /fj.

A.5.2.3-Structural-truss elements and elements of structural diaphragms

having compressive stresses exceeding 0.2 f' shall have special transverse reinforcement, as specified in Section A. 4. 4, over the total length

of the element. The special transverse reinforcement may be discontinued

at a section where the calculated compressive stress is less than 0.15 f^.

Stresses shall be calculated for the factored forces using a linearly

elastic model of the element considered.

A.5.2.4-A11 continuous reinforcement in structural walls, diaphragms,

trusses, struts, ties, chords, and collector elements shall be anchored

or spliced in accordance with the provisions for reinforcement in

tension as specified in Section A. 5. 4.

A. 5. 3-Vertical boundary members for structural walls

A. 5 .3.1-3oundary members shall be provided at edges of structural walls

for which the maximum extreme-fiber stress, corresponding to factored

forces including earthquake effect, exceeds 0.2 f^ unless the entire

wall element is reinforced to satisfy Section A. 4. 4. The boundary

member may be discontinued at a level where the calculated compressive

stress is less than 0.15 f'.

A77
A. 5 .3.2-3oundary members shall have transverse reinforcement as specified

in Section A. 4. 4 along their full length.

A. 5 .3 .3-3oundary members and similar elements shall be designed to carry

all gravity loads on the wall, including tributary loads and self-weight,

as 'well as the vertical force required to resist the overturning moment

caused by earthquake.

A.5.3.4-Transverse reinforcement in the walls shall be anchored within

the confined core of the boundary member to develop the yield stress in

tension of the transverse reinforcement

A.S-ooints of frames

«

A. 6.1 -General requirements

A. 6.1. 1-Forces in longitudinal beam reinforcement at the joint face shall

be determined by assuming that the stress in the flexural tensile reinforcement is 1.25 f .

A. 6. 1.2-Strength of joint shall be governed by the appropriate strength

reduction factors specified in Section 9.3. Section A. 2. 3.1 shall not

apply to joints.

A.6.1.3-3eam longitudinal reinforcement terminated in a column shall be

extended to the far face of the confined column core and anchored in

tension according to Section A. 6. 4 and in compression according to

Chapter 12.

A.5.2-Transverse reinforcement

A. 6 .2.1-Transverse hoop reinforcement , as specified in Section A. 4.

shall be provided within the joint, unless the joint is confined by

structural elements as specified in Section A. 5. 2. 2.

A78
A. 6 .2.2-Within the depth of the shallowest framing member, transverse

reinf orcement equal to at least one-half the amount required by Section

A. 4. 4 shall be provided where members frame into all four sides of the

joint and were each member width is at least three-fourths the column

wi dth.

A.6.2.3-Transverse reinforcement as required by Section A. 4. 4 shall be

provided through the joint to provide confinement for longitudinal

reinforcement outside the column core if such confinement is not provided

by a beam framing into the joint.

A. 5. 3-Shear stress

A.5.3.1-7he design shear strength of the joint shall not exceed yA. !f\

^ J V c for normalweight concrete. The coefficient v shall not exceed 16 if

members frame into all vertical faces of the joint and if each framing

member covers at least three-quarters of the width and three-quarters of

the depth of each joint face. Otherwise, the coefficient Y shall not

exceed 12.

• A.5.3.2-For lightweight concrete, the joint shear stress shall not exceed

three-quarters of the limits given in Section A. 5. 3.1, where A. is the

w minimum sectional area of the joint in a plane parallel to the axis of

the reinforcement generating the design shear conroentary' force.

A. 6 .4-Anchorage length for reinf orcement in tension

A.6.4.1-The anchorage length, 2^, for a bar with a standard 90-degree

hook in normalweight concrete shall not be less than 3d^, 6 in., and

the length required by Eq. (A—4 )

for bar sizes No. 3 through No. 11.

For lightweight concrete, the anchorage length for a bar with a standard

hook shall not be less than 10d. ,7.5 in., and 1.25 required by Eq. (4-4).

A79
A.6.4.2-The 90-degree hook shall be located within the confined core of a column or of a boundary member.

A.S.4.3-For bar sizes No. 3 through No. 11, the anchorage length, l , for a straight bar shall not be less than (a) twice the length required

by Section A. 5. 4.1 if the depth of the concrete cast in one lift beneath

the bar does not exceed 12 in. and (b) 2.3 times the length required by

Section A. 6. 4.1 if the depth of the concrete cast in one lift beneath the

bar exceeds 12 in.

A.5.4.4-For bar sizes No. 14 and No. 18, the anchorage length for a straight bar shall not be less than 1.5 times that required by Section

A. 6 .4.3.

A. 5. 4. 5-Straight bars terminated at a joint shall pass through the

confined core of a column or of a boundary member.

A. 7 Shear -strength requirements

A. 7. 1-Design forces

A.7.1.1-For frame elements subjected primarily to bending, the design

shear force shall be determined from consideration of the statical forces

on the portion of the element between faces of the joints. It shall be

assumed that moments of opposite sign, corresponding to probable strength,

act at the joint faces and that the member is loaded with the factored

tributary gravity load along its span. The moments corresponding to

probable strength shall be calculated using the properties of the member

at the joint faces without strength reduction factors and assuming that

the stress in the tensile reinforcement is equal to at least 1.25 f .

A.7.1.2-For frame elements subjected to combined bending and axial load,

the design shear shall be determined from consideration of the forces on the member, with the nominal moment strengths calculated for the maximum

factored axial compressive design force on the column, acting at the

faces of the joints.

A80
A.7.1.3-For structural walls, diaphragms and trusses, the design shear

force shall be obtained from the lateral load analysis in accordance with

the factored loads and combinations specified in Section 9.2.

A. 7 .2-Trans verse reinforcement in frame elements

A.7.2.1-For determining the required transverse reinforcement in frame

elements in which the earthquake- induced shear force determined in

accordance with Section A. 7. 1.1 represents one-half or more of total

design shear, the quantity V shall be assumed to be zero if the

w factored axial compressive force, related to earthquake effects, is less

than (A f 1/20).

g c

A. 7. 2. 2-Stirrups or ties required to resist shear shall be hoops over

lengths of members as specified in Sections A. 3. 3, A. A. 4, and A. 5. 2.

A. 7. 3-Shear strength of structural walls and diaphragms

A.7.3.1-The nominal shear strength, V , of structural walls and

diaphragms shall not exceed that given by Eq. (A-5).

(A-5)

A

c = net area of concrete section resisting shear bounded by web thickness and heiaht of section.

3 reinforcement ratio A /A_, where A„ is

5 a C 5a

of total area of reinforcement crossing

the projection on A

c the plane of A

0

f^ 3 compressive strength of the concrete in psi.

f 3 yield strength of reinforcement perpendicular to the area A . j

c

A. 7 .3.2-Reinforcement ratio p^, indicating the amount of reinforcement

perpendicular to the direction of reinforcement corresponding to p , shall be equal to or exceed p .

A81
A.7.3.3-The nominal shear strength of all wall piers sharing a common

lateral force shall not exceed 8A„ ff' where A is the total crossc v c c sectional area and the nominal shear strength of any one of the individual wall piers shall not exceed 10 A [Tx where A represents the

cp v c cp

sectional area of the pier considered.

A.7.3.4-The nominal shear strength of horizontal wall elements shall not

exceed 10 A JT^ where A represents the sectional area of a horizontal wall

element.

A. 3-Frame elements not proportioned to resist forces induced by earthquake

moti ons.

A. 3. 1-All frame elements assumed not to be part of the lateral force

resisting system shall be investigated and shown to be adequate for

vertical load carrying capacity with the structure assumed to have

deformed laterally four times that calculated for the specified lateral

forces. Such elements shall satisfy the minimum reinforcement requirements specified in Sections A. 3. 2.1 and A. 5. 2.1 as well as those

specified in Chapters 7, 10, and 11.

A. 3. 2-All frame elements with factored axial compressive forces exceeding

(A f^/10) shall satisfy the following special requirements unless they

comply with Section A. 4. 4.

A. 3. 2. 1-Ties shall have 135-degree hooks with extensions not less than

six tie diameters or 4 in. Cross-ties, as defined in this Appendix, may

be used.

A.3.2.2-The maximum tie spacing shall be s. over a length Z measured

from the joint face. The spacing s Q

shall be not more than (a) eight

diameters of the smallest longitudinal bar enclosed, (b) 24 tie diameters,

and (3) one-half the least cross-sectional dimension of the column. Tne

length shall not be less than (a) one-sixth of the clear heignt of

the column, (b) the maximum cross-sectional dimension of the column, and

(c) 13 in.

A82
A.S.2.3-The first tie shall be within a distance equal to 0.5 s Q

from

the face of the joint.

A.3.2.4-The tie spacing shall not exceed 2 s q

in any part of the column.

A. 9-Construction joints

A. 9.1 -Construct ion joints in structural walls, diaphragms, and other

members resisting lateral forces induced by earthquake shall be designed

to resist the design forces at the joint.

i

A.9.2-Where shear is resisted at a construction joint solely by friction

between two roughened concrete surfaces and dowel action, the factored

shear force across the joint shall not exceed V. determined from

Eq. (A-6 )

V

j

A

vf

f

y

+ °- 75 p

j

where A ^ represents the total amount of reinforcement (including

flexural reinforcement) normal to the construction joint acting as shear-friction reinforcement and Pj is the algebraic sum of the

gravity and earthquake forces on the joint surface acting simultaneously with the shear. For lightweight' concrete, the shear strength

V. calculated from Eq. (A-o) shall be multiplied by 0.75.

A.9.3-The surfaces of all construction joints in elements resisting

lateral forces shall be thoroughly roughened.

A83
COMMENTARY

APPENDIX A - REQUIREMENTS FOR REINFORCED CONCRETE BUILDING STRUCTURES

RESISTING FORCES INDUCED BY EARTHQUAKE MOTIONS

A. 2-General requirements

.A. 2. 1-Scope

This chapter contains a set of specifications which are currently

considered to be the minimum requirements for producing a monolithic

reinforced concrete structure with adequate proportions and details to

make it possible for the structure to undergo a series of oscillations

into the inelastic range of response without critical decay in strength.

The demand for integrity of the structure in the inelastic range of

response is created by the rationalization of design forces specified

by documents such as the 1974 report of the Seismoloay Committee of the

A 1 Structural Engineers Association of California. *

The lateral design forces specified in Reference A.l are considerably

less than those corresponding to linear response for the anticipated

A 2 A 3 A 4 earthquake intensity. * * * ’

*

' As a properly detailed reinforced

concrete structure responds to strong ground motion, its effective

stiffness decreases and its capability to dissipate energy increases.

These developments tend to reduce the response accelerations or lateral

inertia forces with respect to those forces calculated for a linearly

A

" elastic model of the uncracked and moderately damped structure.'

’ w

Thus, the use of design forces representing earthquake effects such as those in Reference A.l requires that the structure be able to respond

in the inelastic range without critical failures. The extent of

required nonlinear response is not explicitly established. It is a function of the type and strength of the structure as well as the

nature of the, ground motion. It is generally assumed that, with the

currently used design forces and anticipated earthquake motions, the

rotations at connections of reinforced concrete frames are likely to

exceed six times the yield rotation. A structural wall similarly

A84
proportioned, would be likely to develop relatively less inelastic

response. In either case it is essential to have a lateral-force

resisting system which will sustain a substantial portion of its

strength as it is subjected to successive reversals of displacements

into the inelastic range.

The perennial question of a trade-off between strength and special

detail requirements has been considered at length. Given a design

earthquake intensity or a design response spectrum indexed by an effective peak acceleration, it appears plausible to soften or

relinquish some of the detail requirements if the design strength is

increased with respect to the minimum code requirement. However,

available knowledge on ground motion and structural response to such

motion does not make precise estimates of inelastic displacement

possible for all structures at large. Furthermore, it is not currently

possible to devise explicit quantitative relationships between the

required extent and number of inelastic displacements and required

reinforcing details. The choice is between (1) a syst&m with sufficient strength to respond to the ground motion within the linear or nearly linear range of rep on se and (2) a system with special details

to permit nonlinear response without critical loss of strength. . The

requirements in this appendix have been developed in relation to the

second option, on the assumption that the design forces are based on Reference A.l or a conparable document having a similar approach to the

determi nation of design farces.

The code sections cited in Section A. 2. 1.3 (which refers to zones of

moderate seismic risk) govern reinforcement details of the structuralframe components as follows:

Girders Columns

Longitudinal Reinforcement A. 3.2 A. 4.

Transverse Reinforcement A. 3. 3 A. 3.

Requirements of Section A. 3. 2, which have been developed for columns

not resisting earthquake effects in high seismic risk zones, apply to

columns designed for earthquake effects in moderate seismic risk zones.

A85
There are no special requirements for other structural or nonstructural

components of buildings in zones of moderate seismic risk.

In regions of high seismic risk, the entire building, including the

foundation and nonstructural elements, must satisfy Appendix A

(Section A. 2. 1.4)

Field and laboratory experience which has led to the special proportioning and detailing requirements in Appendix A has been predominantly with monolithic reinforced concrete building structures.

Therefore, the projection of these requirements to other types of

reinforced concrete structures, which may differ in concept or fabrication from monolithic construction, must be temoered by relevant

physical evidence and analysis. Precast and/cr prestressed elements

may be used for earthquake resistance provided it is shown that the

resulting structure will satisfy the safety and serviceability (during

and after the earthquake) levels provided by monolithic construction.

The "toughness" requirement in Section A. 2. 1.5 refers to the concern

for the integrity of the entire lateral -force structure at lateral

displacements anticipated for gound motions corresponding to design

intensity. Depending on the energy-dissipation characteristics of the

structural system used, such displacements may have to be .more than

those for a monolithic reinforced concrete structure.

A. 2. 2 -Ana lysis and proportioning of structural elements

It is assumed that the distribution of strength to the various

conponents of a lateral-force resisting system will be guided by the

analysis of a linearly elastic model of the system acted on by the

factored forces.

Because the design basis is assumed to admit nonlinear response, it is

necessary to investigate the stability of the lateral load resisting

system and its interactin with other structural and nonstructural

elements at displacements larger than those resulting from linear

A86
analysis. To handle this problem without having to resort to nonlinear

response analysis, one option is to increase by a factor of four the

displacements from linear analysis for the specified lateral forces,

providing an approximate measure of displacement in the event of a design earthquake, unless the governing code specifies the factors to

be used as in References A. 6 and A. 7.

The main concern of Appendix A is the safety of the structure. The

intent of Sections A.2.2.1 and A. 2. 2. 2 is to draw attention to the

influence of nonstructural elements on structural response and to

hazards from falling objects.

Section A. 2 .2.3 is included because the base of the structure as defined in analysis may not correspond to the foundation level.

A.2. 3 -Strength reduction factors.

Section A. 2. 3.1 refers to brittle elements carrying earthquake induced

forces such as low-rise walls or portions of walls between openings of

which proportions are such that it becomes impractical to reinforce

them to have their nominal shear strength in excess of the shear

corresponding to nominal flexural strength for the pertinent loading

conditions. This requirement does not apply to the design of connections.

Section A. 2. 3.2 is included to discourage the use of tied columns to

resist earthquake induced forces.

The strength reduction factor of 0.65 is to be used in Eq. (A-4) in

determining anchorage length of reinforcing bars with standard hooks.

It applies only to anchorage of reinforcement essential to the integrity of the lateral -force resisting structure.

0 A. 2. 4-Concrete in elements resisting earthquake-induced forces

The requirements of this section refer to the concrete quality in

frames, trusses, or walls proportioned to resist earthquake-induced

A87
forces. The maximum design compressive strength of lightweightaggregate concrete is limited to 4,0C0 psi primarily because of paucity

of experimental and field data on the behavior of elements, made with

lightweight concrete, subjected to displacement reversals in the

nonlinear range.

A. 2. 5-Reinforcement in elements resisting earthquake-induced forces

The use of longitudinal reinforcement with substantially higher

strength than assumed in design may lead to primary shear or bond

failures which are to be avoided even if such failures may occur at

higher loads than those anticipated in design. Therefore, an upper

limit is placed on the strength of the steel.

To insure adequate inelastic rotation in frame elements it is essential to use a reinforcement with an ultimate stress well in excess of

the yield stress. For the same reason, any splice must be able to

develop a stress equal to 1.25 times the nominal yield stress of the

reinforcement.

A.3-Flexural elements of frames

A. 3.1 -Scope

This section refers to horizontal elements of girders of frames resisting lateral loads induced by earthquake motions. If any horizontal

element is subjected to an axial design compress ice force exceeding

(A f

c/10), in addition to the flexure at any section, it is to be

treated as a column as described in Section A. 4.

Experimental evidence * indicates that under reversals of displacement into the nonlinear range, behavior of continuous elements having

length -to -depth ratios of less than four is significantly different

from the behavior of relatively slender elements. Design rules derived

from experience with relatively slender elements do not apply directly

to elements with length-to-depth ratios less than four, especially with

respect to shear strength.

A88
The geometric constraints indicated in Sections A. 3. 1.3 and A. 3. 1.4

derive from practice with reinforced concrete frames resisting

A 1

earthquake induced forces.

A. 3. 2-Longitudinal reinforcement

Section 10.3.3 limits the tensile reinforcement ratio in a flexural

member as a fraction of the amount which would produce balanced strain

conditions. For a section subjected to bending only and loaded monotonically to yielding, this approach is feasible because the likelihood

of compressive failure can be estimated reliably with the behavioral

model assumed for determining the reinforcement ratio corresponding to

"balanced" failure. The same behavioral model (because of incorrect

assumptions such as linear strain distribution, well-defined yield

point for the steel, limiting compressive strain in the concrete of

0.003, and compressive stresses in the shell concrete) fails to

describe the conditions in a flexural member subjected to reversals

of displacements well into the inelastic range. Thus, there is little

rationale for continuing to refer to "balanced conditions" in earthquake resistant design of .reinforced concrete structures.

The limit of 0.025 is based primarily on considerations of steel

congestion and, indirectly, on limiting shear stresses in girders of

typical proportions. The minimum requirement of two No. 5 bars, top

and bottom, refers again to construction rather than behavioral

requirements.

Lap splices of reinforcement (Section A .3.2.3) are prohibited at

regions where flexural yielding is anticipated because such splices

are not considered reliable under conditions of cyclic loading into

the inelastic range. Transverse reinforcement for lap splices at

any location are mandatory because of the likelihood of loss of shell

concrete.

0

A.3.3-Transverse reinforcement

A88A

Special transverse reinforcement is required primarily for confining

the concrete and maintaining lateral support for the reinforcing bars

in regions where yielding is expected. Examples of hoops suitable for

flexural elements of frames are shown in Figs. A-l and A-2.

Consacutiva Cross Ties

Shall Hava Thetr 90-da<3rea

.Hooks On Opposite Sides of Column

1

;'. r

#:• ; - •• '.j. . *

* / *. ..

• *. . •. *y •V Vf.; ;

•

•

•, I

# *• 4 •••- ‘ 1

j. I’:.-.’-** 7 1 , # • 'V. ;

t

'* *•"! . Y .

• .• *

. ^

\ ' 4

:

’

: •> • 0 -^S

%

•*

*

,

. * *

*

j

V -

•** • • i *’ *

; : \‘ *

’

.. v \ #* • : >

X

' X X —

1

x Shall Not Exceed 14 inches

Fla. A-l

In the case of elements with varying strength along the span or elements

for which the permanent load represents a large proportion of the total

design load, concentrations of inelastic rotation may occur within the

span. If such a condition is anticipated, transverse reinforcement

must be provided throughut the region where yielding is expected.

Ottm A

•

• ... _

F

-

•f

iiJ

} 1

•

1

j-n

t...

r*. 1

’

* i - !

4

1 VI

-.1

. I

: -j

•

i

a-d* d

r: i

: • 1

: - 1

- 1 a

t *

Fig.

jr Qtiati 3 V"4

! I! i

^

Q«tt» C 0«m 3 ^9

r

t • f

•

1 p5C

: - i

i

'

I r m

r -

1

-.-I

• •

• . * • 1

•

j

• • i

i

<•*

* ! **

i

•."..J

: . 1

• , j >1

rx- d v•

A-2

A89
A. 4-Frame elements subjected to bending and axial load

A. 4.1-Scope

This section applies to elements carrying axial loads or columns of

frames proportioned to resist earthquake forces. The geometric constraints required by Sections A. 4. 1.1 and A. 4. 1.2 follow from previous

A 1 practice with columns.

A. 4. 2-Relative strength of columns

The intent of Section A. 4. 2.1 is to limit flexural yielding to the

horizontal elements of the frame. If this requirement cannot be

satisfied at a joint as, for example, in the case of heavy transfer

girders, additional transverse reinforcement is required in the columns

affected by forces at the joint.

A. 4. 3-Longitudinal reinforcement

The lower bound to the reinforcement ratio in elements carrying axial

forces as well as flexure refers to the traditional concern for the

effects of time-dependent deformations of the concrete as well as desire to avoid a sizeable difference between the cracking and yielding moments. The upper bound reflects concern for steel congestion,

load transfer in low-rise construction, and the development of large

shear stresses in columns of ordinary proportions.

Spalling of the shell concrete, which is likely to occur near the ends

of the column in frames of typical configuration, makes lap splices in

those locations quite vulnerable. If lap Splices are to be used at

all, they must be located near the mid-height where stress reversal is

likely to be limited to a smaller stress range than at locations near

the joints.

Welding and mechanical splices may occur at any level but not more than

half the bars may be spliced at any one section.

A90
A.4.4-Transverse reinforcement

The main reason for the requirements in this section is concern for

confining the concrete and providing lateral support to the reinforcement.

For axially compressed elements subjected to steadily increasing load,

'the effect of helical (spiral) reinforcement on the strength of the

confined concrete has been well established. * Eq. (10-3) follows

from the arbitrary design concept that, under axial loading, the maximum capacity of the column before loss of shell be equal to that at

large compressive strains with the spiral reinforcement stressed to its

useful limit. The toughness of the axially loaded '‘spiral" column is

not directly relevant to its role in the earthquake-resistant frame

where toughness or ductility is related to its performance under

reversals of moment as well as axial load. For the earthquake problem,

there is no reason to modify Eq. (10-5) other than adding the varying

lower bound given by Eq. (A-l) which governs for larger columns with

gross cross-sectional area, A , less than approximately 1.26 times

the core area, A . c

A q Aid A H

A conservative evaluation of the available data * *

* on the

effect of rectilinear transverse reinforcement on the behavior of

reinforced concrete would suggest that such reinforcement has little

influence on strength but improves ductility although not as effectively as spiral reinforcement. Consequently, there is no explicit

basis for relating the required amount of rectilinear transverse to

spiral transverse reinforcement. However, it is evident that

rectilinear transverse reinforcement is less efficient and if it is

used there should be more of it to have an effect comparable to that of

spiral reinf orcement. Thus, Eq. (A-l) and (A-3) compare to Eqs. (10-5)

and (A-2), respectively, but Eq. (A-l) and (A-3) require more reinforcement per 'unit length of column.

The requirement of Eq. (A-2) which governs for large sections is

ignored if the design stresses on the gross section are low.

A91
The transverse reinforcement required by Eq. (10.5), (A-l), (A-2), and

(A-3) is distributed over regions where inelastic action is considered

to be likely (Section A. 4. 4. 4).

Fig. A-l shows an example of transverse reinforcement provided by two

hoops and a cross-tie.

Dynamic response analyses and field observations indicate that columns

supporting discontinued stiff elements such as walls or trusses, tend

to develop considerable inelastic response. Therefore, it is required

that these columns have special transverse reinforcement throughout

their length. This rule covers all columns beneath the level at which

' the stiff element has been discontinued.

A.5-Structural walls, diaphragms, and trusses

A. 5. 1-Scope

This section contains requirements for the dimensions and details of

relatively stiff structural systems including parts of roof and floor

systems transmitting inertia forces as well as walls and trusses.

Stubby frame elements, which constitute parts of the lateral force

resisting system, must also satisfy the requirements of this section.

A . 5 . 2-Re i nforcement

Reinforcement minima (Sections A. 5. 2.1 and A. 5. 2. 3) follow from

preceding codes. The uniform-distribution requirement of the shear

reinforcement results from the intent to control the width of inclined

cracks. The requirement for two layers of reinforcement in walls

carrying substantial design shears is based on the observation that,

under ordinary construction conditions, the probability of maintaining

the location of a single layer of reinforcement near the middle of the

wall plane is quite low. Conpressive stress calculated for the

factored forces acting on a linearly elastic model of the structural

A92
element is used as an index value to determine whether confining reinforcement is required. A calculated compressive stress of 0.2 f'

r on an element is assumed to indicate that integrity of the entire structure

is dependent on the ability of that element to resist substantial

conpressive force under severe cyclic loading. Therefore, transverse

reinforcement, as specified in Section A. 4. 4, is required in such

elements to provide confinement for the concrete and the compressed

reinforcement (Section A. 5. 2. 4). If this requirement should govern in

a solid floor slab, it may be satisfied by a boundary member, as defined in Section A. 5. 3, rather than providing confinement for the

entire slab.

3ecause the actual stresses in longitudinal reinforcing bars of stiff

elements may exceed the calculated stresses, it is required (Section

A. 5.2. 5) that all continuous reinforcement be developed fully.

A. 5. 3-Vertical boundary menfcers for structural walls

A simplified diagram showing the forces on the critical section A-A of

a structural wall acted on by permanent loads, W, and the maximum shear

and moment induced by earthquake in a given direction are shown in Fig.

A-3. Under the given conditions, the compressed flange is required to

resist the acting gravity load plus the total tensile force generated

in the vertical reinforcement (or the compressive force associated with

the bending moment at section A-A). Recognizing that this loading

condition may be repeated many times during the strong motion, it

becomes essential to confine the concrete in all wall flanges where the

congress ive forces are likely to be large as indicated by the design

compressive stress exceeding 0.2 f' (Sections A. 5. 3.1 and A. 5. 3. 2).

The stress is to be calculated for the factored forces on the section

assuming linear response of the gross concrete section. The compressive

stress of 0.2 f' is used as an index value and does not describe the

c conditions which may arise at the critical section under the influence

of the actual inertia forces for the anticipated earthquake intensity.

A93
^ '////////////////////////////;;/>///V//>7)/V//yssssss>. ~

Fig. A3

The requirement in Section A. 5. 3. 3 is based on the assumption that the

boundary element may have to carry all compressive forces at the

critical section at the time when maximum lateral forces are acting cn the structural wall. The design requirements involve only the section

properties: Tne cross section of the boundary ’element must have

adequate strength (calculated as an axially loaded column) to resist

the factored axial compressive force at the critical section.

Because the horizontal reinforcement in walls requiring boundary merroers

is likely to act as web reinforcement, it should be fully anchored in

the boundary menders which act as flanges (Section A. 5. 3.4). To achieve

this anchorage is made difficult by stress reversals, by and the possibility of large transverse cracks in the boundary members, wherever

feasible standard hooks or mechanical anchorage schemes should be

considered.

A.S-Coints of frames

A. 5. 1-General requirements

A94
Development of inelastic rotations at the faces of joints of

reinforced concrete frames is associated with stresses in the flexural

reinforcement well in excess of the yield stress. Consequently, joint

shear stresses generated by the flexural reinforcement are calculated

for 1.25 f in the reinforcement (Section A.6.1.1). An explanation

of the reasons for the high stresses in girder tensile reinforcement is

provided in Reference A. 12.

8ecause the design requirements for joints were developed recognizing

that the strength of a joint is typically governed by a brittle mode of

failure. Section A. 2. 3.1 does not apply to joints. The appropriate

strength -reduct ion factor is 0.35 for shear strength.

A. 6.2 -Transverse reinforcement

However low the calculated shear stresses in a joint of a frame

resisting earthquake-induced forces, confining reinforcement (Section

A. 4. 4) must be provided through the joint around the column reinforcement (Section A. 6. 2.1). Confining reinforcement may be reduced if

horizontal menfcers frame into all four sides of the joint as described

in Section A. 6. 2. 2.

At joints where the girder is wider than the column, girder reinforcement not passing through the confined core of the column is to be

provided with lateral support is provided by framing into the joint.

A. 6. 3-Shear stress

The requirements for the proportioning of joints in Appendix A are

based on Reference A. 12 in that behavioral phenomena within the joint

are interpreted in terms of a nominal shear stress. 3ecause tests of

A 19 A 20

joints * and deep beams indicated that shear strength was not

as sensitive, to joint or web reinforcement as implied by the express' on developed by ACI Cornnittee 325^*^ for beams and adopted to apnly to

joints by ACI Committee 352, it was decided to permit a constant shear

stress (derived from the data in Reference A. 19) in a joint core having

a minimum amount of transverse reinf orcement as specified in Section

A. 6.2.

A95
The designer should note that the joint problem is better solved in

proportioning the girders and that tensile stresses may exist in a continuous beam bar through an interior joint at both faces of the

joint because of limited anchorage length.

A. 5 .4- Anchorage length of bars in tension

Eg. ( A—4 ) provides a routine for determining the minimum anchorage

length of. deformed reinforcing bars with standard hooks embedded in

confined concrete made with norma Iweight aggregate. It is based on

A 23 recomnendations of ACI Conmittee 408. Because the hook is

specified to be located in confined concrete, special multipliers for

confinement conditions proposed by ACI Comnittee 408 have been eliminated to simplify calculations.

The anchorage length in tension for a .reinforcing bar with a standard

hook is defined as the distance, parallel to the bar, from the critiical section (where the bar is to be developed) to a tangent drawn to

the outside edge of the hook. The tangent is to be drawn perpendicular

to the axis of the bar as shown in Fig. A-4.

Note I Hook Must 9e

Within Contined Core.
For lightweight concrete, the length required by Eq. (A-4) is increased

by 25 percent.

Eq. (A-4) is not intended for use with No. 14 and No. IS bars having

standard hooks.

The strength reduction factor to be used in Eq. (A-4) is 0.65

(Section A. 2 .3.3). It has been reduced from 0.8 proposed by ACI

Committee 408 because of the effects of load reversals.

Section A. 6. 4. 3 specifies the minimum anchorage length for straight

bars as a multiple of the length indicated by Section A. 6. 4.1. Case

(b) of Section A. 6. 4. 3 refers to "top" bars.

t

Even though Eq. (A-4) does not apply to hooked No. 14 and No. 13 bars,

it is to be used to determine anchorage lengths for straight No. 14 and

No. 13 bars. Straight bars are to pass through the confined core in

all cases even if the entire anchorage length cannot be accommodated

within the confined core.

A. 7-Shear-strength requirements

A. 7.1 -Design forces

In determining the equivalent lateral forces representing earthquake

effects for the type of frames considered it is assumed that frame

elements will dissipate energy in the nonlinear range of response.

Unless a frame element possesses a strength that is a multiple, on the

order of three to four, of the design forces, it must be assumed that

it will yield in the event of the design earthquake. The design shear

force must be a good approximation of the maximum shear that may

develop in an element. Therefore the design shear for frame elements

is related to the flexural strength of the designed element, rather

than to the shear indicated by lateral-load analysis. The conditions

described by Sections A. 7.1.1 and A. 7. 1.2 reflect this requirement.

3ecause girders are assumed to develop extensive nonlinear response,

design shears in the girders are- determi ned using stresses in the IcnaiA97
tudinal reinforcement (1.25 f ) which reflect the effects of strain

A. 12 y

hardening. *

- Column design shears (Section A. 7. 1.2) are determined

on the basis of limiting moments calculated from interaction diagrams.

In both cases strength-reduction factors are assumed to be unity.

C«*iqn

Crtvtty Ladd n Oirecriorf of Sh«cr "crt:»

*— £nd Mom«nr* 3as*d Cn T«nsii« Sfrtsa « i.2S f, “ Wh*r* ty is fft* So«cifitd Yi«id Strsss. ( 2atn Lid

Mom«nfs Shouia 3* Ccnsietrvd n Barn Oirscttons,

CIocXviss end Gsunrtraocxvisa).

Ham • 3ofti Cud Momvnrs Should 3« Carrswarw

'ft 3cm Oirecrion*, Clocrwia* one CduaromocxwiM.

Fig. A-5

Design shears for structural walls, trusses, and diaphragms are

obtained from the lateral-load analysis with the appropriate load

factors. (However, the designer should consider the possibility of

yielding in conponents of such structures, as in the portion of a wall

between two window openings, in which case the actual shear may be well

0 in excess of the shear indicated by lateral-load analysis based on factored design forces.)

The term "probable strength" in Section A. 7.1 refers to moment strength

calculated with i s 1.0 and f = 1.25 f

A98
A.7.2-Transverse reinforcement in frame elements

Experimental studies at various laboratories of reinforced concrete

elements subjected to cyclic loading have demonstrated that more web

reinforcement is required to insure a flexural failure if the element

is subjected to alternating nonlinear displacements than if the element

is loaded in one direction only, the necessary increase of web reinforcement being higher in the case of no axial load. This observation

is reflected in the specifications (Section A. 7. 2.1) by eliminating the

term representing the contribution of concrete to shear resistance.

However, this stratagem, chosen for its relative simplicity, should not

be interpreted to mean that no concrete is required to resist shear.

On the contrary, it may be argued that the concrete core resists all

the shear with the web reinforcement confining and thus strengthening

the concrete. The confined concrete core plays an important role in

the behavior of the beam and should not be reduced to a minimum*just

because the design expression does not recognize it explicitly.

3ecause spalling of the concrete shell is anticipated during strong

motion, especially at and near regions of flexural yielding, all web

reinforcement must be provided in the form of closed hoops as defined

in Section A. 7. 2. 2.

A. 7. 3 -Re inforcement in structural walls and diaphragms

Eq. (A— 5) has been selected for general use primarily because it

provides a simple and familiar vehicle for the determination of the

required amount of transverse reinf orcement. To differentiate between

stubby and slender walls was considered to be unwarranted considering

the increased calculation effort the differentiation requires would be

likely to offset any economy in material it might effect.

The requirement for the distribution of calculated shear stress in

walls working in parallel reflects the need to avoid overloading one of

the piers while the others are barely loaded.

A99
"Horizontal wall element" in Section A. 7. 3. 4 refers to wall sections

between two vertically aligned openings (Fig. A-o).

Fig. A—

o

A. 3-Frame elements not proportioned to resist forces induced by earthauak

motions.

The intent of Section A. 3.1 is to insure that the parts of the structural system, designed for gravity loading only, will continue to be

functional at lateral displacements for which the lateral -force res is

ing system has been designed. Consequently, the gravity-load system

need only accomnodate the specified lateral displacements without

reduction in gravity-load carrying capacity. Reduction in flexural

stiffness of reinforced concrete elements qf the gravity-load system

may be recognized in calculations. It is not necessary to reinforce

the gravity-load system for moments related to lateral forces.

AlOO
A. 9-Construction joints

Construction joints require explicit attention during the design as well as the construction of a building. Eq. (A-6) reflects the

influence on shear strength of the estimated net force normal to the

construction joint. It should be noted that the normal force related

to the lateral motion will reduce the compressive force due to

gravity. A positive value for P

n refers to compression on the joint.

References

A.l "Reconmended Lateral Force Requirements and Commentary," Structural

Engineers Association of California, San Francisco, 1974, 21 pp.

A. 2 Blume, J. A., Newmark, N. M. and Corning, L. H., "Design of Multistory

Reinforced Concrete Buildings for Earthquake Motions," Portland Cement

Association, Skokie, 1961, 313 pp.

A. 3 Clough, "Dynamic Effects of Earthquakes," Journal of the Structural

Division, ASCE, V. 86, No. ST4, April 1960, pp. 49-65.

A. 4 Housner, G. W., "Limit Design of Structures to Resist Earthquakes,"

Proceedings, World Conference on Earthquake Engineering, EERI,

Berkeley, Calif., 1956, pp. 5-1 to 5-13.

A. 5 Gulkan, P. and Sozen, M. A., "Inelastic Response of Reinforced Concrete

Structures to Earthquake Motions," AC I Journal, V. 71, No. 12, Dec.

1974, pp. 601-609.

A. 6 "Tentative Provisions for the Development of Seismic Regulations for

Buildings" Applied Technology Council, San Francisco, Calif., 1973

(Printed by U.S. Govt. Printing Office, Washington, D.C., 1973).

M A. 7 "Earthquake-Resistant Design Requirements for YA Hospital Facilities,"

Office of Construction, Veterans Admi nistration, March 1975, Washington,

D.C.

A101
A. 8 Committee on R/C Columns, Building Research Institute of Japan,

"Experimental Research on Improving Ductility of Reinforced Concrete

Columns under Cyclic Lateral Loads (in Japanese)," Concrete Journal,

V. 13, No. 1, Jan. 1975, pp. 2-18.

A. 9 Richart, F. E., 3randtzaeg, A., and Brown, R. L., "The Failure of

Plain and Spirally Reinforced Concrete in Compression," University of

Illinois Engineering Experiment Station Bulletin No. 190, Urban a, April 1929, 74 pp.

A. 10 Roy, H. E. H., and Sozen, M. A., "Ductility of Concrete," Proc. of the

Int. Symposium on Flexural Mechanics of Concrete, Miami, ACI Special

Publication No. 12, No. Y. 1964, pp. 213-235.

A. 11 Burdette, E. G., and Hilsdorf, H. K., "Behavior of Laterally

Reinforced Concrete Columns," Journal of the Structural Division,

ASCE, V. 97, No. ST2, Feb. 1971, pp. 587-602.

A. 12 ACI-ASCE Committee 352, "Reccmnendations for Design of Beam-Column

Joints in Monolithic Reinforced Concrete Structures," ACI Journal,

Proc. V. 73, No. 7, July 1976, pp. 375-393.

A. 13 Ikeda, A., "Load-Deformation Characteristics of Reinforced Concrete

Columns Subjected to Alternative Loading" (in Japanese), Report of the

training Inst, for Eng. Teachers, Yokohama National University, March

1968, 9 pp.

A. 14 Popov, E. P., Bertero, V. V., and Krawinkler, H., "Cyclic Behavior of

Three R/C Flexural Members with High Shear," Report EERC 72-5, University of California, Berkeley, Oct. 1972.

A. 15 Wight, J. K., and Sozen, M. A., "Shear Strength Decay in Reinforced

Concrete Colunfns Subjected to Large Deflection Reversals," Journal of

the Structural Division, ASCE, Y. 101, No. ST5, May 1975, pp.

1053-1065.

A102
A. 16 Barda, R., Hanson, J. M., and Corley, W. G., "Shear Strength of

Low-Rise Walls with Boundary Elements," AC I Special Publication,

Reinforced Concrete Structures in Seismic Zones , Detroit, 1975.

A. 17 Cardenas, Alex E., and Magura, D. D., "Strength of High-Rise Shear

Walls of Rectangular Cross Sections," ACT Special Publication SP-36,

1973, pp. 119-150.

A. 18 Mattock, A. H., Chen, K. C. , and Soongswang, K., "The Strength of

Reinforced Concrete- Corbels," Report SM 75-3, Dept, of Civ. Eng.,

University of Washington, Seattle, 34 pp.

A. 19 Meinheit, D. F., and Jirsa, J. 0., "The Shear Stregth of Reinforced

Concrete Beam-Column Joints," CESRL Report No. 77.1, Univ. of Texas,

Austin, Jan. 1977.

A. 20 Hirosawa, M., "Strength and Ductility of Reinforced Concrete Members

(in Japanese}," Report of the 3iulding Research Institute No. 76,

Ministry of Construction, March 1977. (Data sumnarized in Report

No. 452, Structural Research Series, Dept, of Civil Engineering,

University of Illinois, Urbana, Illinois, 1978).

A. 21 ACI-ASCE Committee 326, "Shear and Diagonal Tensin," ACI Journal,

Proc. V59, No. 1, Jan. 1962, pp. 1-30; No. 2, Feb. 1962, pp. 277-324;-

No. 3, March 1962, pp. 352-396.

A. 22 International Conference of Building Officials, "Uniform Building

Code," Whittier, California.

A. 23 ACI Committee 408, "Suggested Development, Splice, and Standard Hook

Provisions for Deformed Bars in Tension, Concrete International, July

1979, pp. 44-46.

A103
JOINT BALLOT NUMBER: 4/13

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: //4, Concrete COMMITTEE BALLOT NUMBER: _A1

ATC-3-06 SECTION REFERENCE : 11.1

Alter Section 11.1 such that the reference reads as follows:

"Reference 11.1 Building Code Requirements for Reinforced Concrete,

American Concrete Institute (ACI 318-77) excluding Appendix A and

replacing Section 9.2.3 with Section 3.7.1 of this document."

Final Ballot: Yes

0_ No

4 Abstain

3 Did Not Vote

COMMENTS:

This ballot item updates the reference to include the latest version of the

ACI Building Code for Concrete (ACI 318-77). The replacement of Section 9.2.3

in the ACI Code by ATC 3-06 Section 3.7.1 reminds the designer that the combination of load effects used in ATC 3-06 is different than that in ACI 318-77.

This ballot item appeared on the first of the two committee letter ballots.

The final wording was modified so as to read exactly as revised and approved

by the ATC representative. The abstentions were the result of the ballot

item being superseded by the committee ballot item Y1 ( Joint Ballot Number

4/12). The committee was in full agreement that the reference should be

updated, but the issue of adopting Appendix A overshadowed that intent.

A104
JOINT BALLOT NUMBER: 4/14

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: #4, Concrete COMMITTEE BALLOT NUMBER: A2

ATC-3-06 SECTION REFERENCE: 11.2

Alter Section 11.2, first paragraph, second sentence by inserting "Precast and/or

prestressed" in place of "Precast."

Final Ballot: 5 Yes

0_ No

0 Abstain

3 Did Not Vote

COMMENTS:

The intent of the ballot item is to expressly include prestressed concrete as

a permissible building material. Initially, the ATC representative was opposed

to mention of prestressed construction without any accompanying criteria for

its proper design. However, with the introduction of the material contained

in committee ballot item M9 (Joint Ballot Number 4/15), the ATC representative

approved this change to the existing ATC 3-06 Chapter 11.

A105
JOINT BALLOT NUMBER: 4/15

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: // 4, Concrete COMMITTEE BALLOT NUMBER/:

ATC-3-06 SECTION REFERENCE: New Section 11.9

Add the following as a new Section in Chapter 11 immediately following

Section 11.8:

Section 11.9 STRUCTURES COMPRISED OF PRECAST

AND/OR PRESTRESSED CONCRETE

SUBASSEMBLAGES

The provisions of this Section apply to buildings constructed with precast

and/or prestressed concrete elements not conforming to the detailing provisions

given elsewhere in this Chapter for cast-in-place concrete.

11.9.1 LINEAR ELASTIC DESIGN

Structures with assemblages of precast and/or prestressed concrete components

furnishing lateral resistance against seismic forces shall be designed to

elastically resist equivalent lateral forces equal to those specified in this

document with an R value of 1.0.

OVER

COMMENTS:

The intent of this change to the existing ATC 3-06 Chapter 11 is to provide a clear mechanism by which a designer can use a precast and/or prestressed con- struction within the framework of the ATC 3-06 provisions. Section 11.9.1

presents a method by which a structure can be designed to resist elastically

earthquake forces and which is likely to be an economically viable solution

for low-rise construction only (< 3 stories). Section 11.2 presents a method

which follows the more conventional approach of permitting inelastic action

providing the system offers the same behavioral characteristics (e.g. strength,

stiffness, damping, etc.) as comparable monolithic cast-in-place ordinarily

reinforced concrete construction.

The ATC representative reviewed and approved of the proposed ballot item. There

were two reservations of a technical nature expressed by members of the committee

The first concerned the use of an R value of 1.0 in the Linear Elastic Design

section. The committee member felt that to be overly conservative and suggested

a value of R = 1.5. ' The other reservation accompanied the "No" vote and was

an objection to the lack of a provision limiting the height and/or the number

of stories.

A106
11.9.2 "DUCTILE" CONSTRUCTION

Energy dissipating lateral load resisting systems comprised of precast

and/or prestressed concrete components shall be permitted provided satisfactory evidence can be shown in the form of experiments, testing, and

analysis based upon established engineering principles that the resulting

construction complies with the requirements of Sections 3.6 and 3.7 and

this Chapter, and that they offer the same strength, stiffness, stability,

durability, damping, energy absorption, and energy dissipation capabilities

(ductility) as monolithic cast-in-place ordinarily reinforced concrete

construction

.

Final Ballot: 7 Yes

1 No

0 Abstain

0 Did Not Vote

A107
JOINT BALLOT NUMBER: 4/16

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: //4, Concrete COMMITTEE BALLOT NUMBER: Ml

ATC-3-06 SECTION REFERENCE: 11.5.1

Alter Section 11.5.1, third paragraph such that it reads as follows:

"Reinforcement resisting earthquake-induced flexural and axial

forces in frame elements and in wall boundary members shall comply

with ASTM A706. ASTM A615 Grades 40 and 60 reinforcement may be

used in these elements if (a) the actual yield stress based on mill tests does not exceed the specified yield stress by more

than 18,000 psi (retests shall not exceed this value by more

than an additional 4,000 psi) and (b) the ratio of the actual

ultimate tensile stress to the actual tensile yield stress is

not less than 1.25."

Final Ballot: __8

_0

_0

0

Yes

No

Abstain

Did Not Vote

COMMENTS:

This change replaces the current wording in ATC 3-06 Chapter 11 with the

wording included in the latest draft version of the ACI Committee 318

Appendix A (Requirements for Reinforced Concrete Building Structures

Resisting Forces Induced by Earthquake Motions) . The committee was in

complete agreement that the Appendix A wording was more desirable than

the existing wording. The ATC representative objected to this change

because it did not sufficiently emphasize that if ASTM A615 Grade 60 steel

is used careful attention must be given to the metallurgy of the steel

and the welding practice.

A108
JOINT BALLOT NUMBER: 4/17

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: //4, Concrete COMMITTEE BALLOT NUMBER: M3

ATC-3-06 SECTION REFERENCE: 11 . 8.2

Alter Section 11.8.2 by deleting in its entirety the third paragraph and replace

it with the following:

"A cast-in-place topping on a precast floor system may serve as the

diaphragm provided the cast-in-place topping is proportioned and

detailed to resist the design shear forces under the effects of any

loading combination (which could induce tensile or compressive

stresses simultaneously to the shear forces). For buildings in

performance Categories C and D, alternate techniques based on the

use of untopped precast and/or prestressed components of concrete

floor systems may be used only'if it can be shown by experiments

and analysis based on established engineering principles that they

will offer the same shear strength, stiffness, stability, durability,

and sufficient energy dissipation capacity, as a monolithic castin-place ordinarily reinforced concrete diaphragm."

Final Ballot: 8 Yes 0 Abstain

0 No 0 Did Not Vote

COMMENTS:

’ ~

The ballot item modifies the existing complete restriction against the use of

untopped precast and/or prestressed components of floor systems as diaphragms.

Instead, the change would permit such systems to be considered as diaphragms if

it can be shown that the untopped system provides behavior comparable to that

of a monolithic cast-in-place ordinarily reinforced concrete diaphragm.

The ballot item was reviewed by the ATC representative who supported its

adoption. One committee member, however, expressed reservations about the

practicality of verification and the lack of a commentary section giving a clear explanation of the provision's intent.

A109
JOINT BALLOT NUMBER: 4/18

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: #4, Concrete COMMITTEE BALLOT NUMBER: M4

ATC-3-06 SECTION REFERENCE: 11.6.1

Four part item

a) Alter Section 11.6.1, second paragraph, second sentence so as to read:

"At least two No. 5 or larger bars shall be provided continuously both

top and bottom except in slabs."

b) Alter Section 11.6.1, sixth paragraph, first sentence so as to read:

"Web reinforcement perpendicular to the longitudinal reinforcement

shall be provided throughout the length of all members except slabs ."

c) Alter Section 11.6.1, seventh paragraph, first sentence so as to read:

"Within a distance equal to twice the effective depth from the end of

all members except slabs, the amount ... from the end of the member."

OVER

COMMENTS:

The ballot item introduces design provisions for flat slab construction. Such

provisions are not present in the existing ATC 3-06 Chapter 11 and it was felt

by the committee that such an omission would not be representative of the curre building practice in many areas of the nation.

The ATC representative reviewed and approved of the provisions included in this

ballot item.

While approving this item, committee members expressed concern about the use or unfactored gravity loads in the proposed equation 11-2. The use of untactorea

loads is inconsistent with all other sections of Chapter 11 where factored load

are used.

A110
Four part item (continued)

d) Alter Section 11.6.1 by adding the following paragraph after the seventh

paragraph

"Slabs without beams and supported on columns may be used for ordinary

moment frames provided those slabs satisfy the requirements of Chapter 13

of Reference 11.1 and this Section. Bottom bar reinforcement, Ag , shall

be provided continuous through or anchored within a column and not less

than that given by the following formula:

, =

2 (V-Vp)

s 0. 85fy ( 11- 2 )

where V is the shear force transferred to column due to unfactored gravity

loads and Vp is the sum of the vertical components of the forces in any

prestressing tendons passing through or anchored within the column. At

least two No. 4 or larger bars shall be provided continuous through or anchored within the column in both directions and both top and bottom.

In slabs without beams, column strip negative moment reinforcement shall

be distributed so that at least 60 percent of the required reinforcement

is concentrated within lines one and one-half times the slab thickness

either side of the column. The shear stress, v, on a critical section

located half the effective depth of the slab from the column perimeter,

and caused by the shear force V shall not exceed 2v£'

c

. If there is no spandrel beam at the discontinuous edge of a slab, reinforcement within

four slab thicknesses either side of a column face and adjacent to the

edge shall be detailed so that it can act effectively as torsion reinforcement considering the possibility of full reversals of the sense

of the torsional moments. If the torsional strength of the spandrel

beam framing into a column exceeds the flexural strength of the slab

at its connection with the beam for the adjacent half panel width, all

shear shall be assumed transferred to the column via the beam."

Final Ballot: 8 Yes

0 No

0 Abstain

0 Did Not Vote

Alll
JOINT BALLOT NUMBER: 4/19

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TECHNICAL COMMITTEE: //4, Concrete COMMITTEE BALLOT NUMBER: M5

ATC-3-06 SECTION REFERENCE: Commentary Cll.5.1

Alter Commentary Section 11.5.1, fifth paragraph by including the following

sentence at the end of the paragraph:

"The flat plates of flat plate frames of normal proportions and

detailed as specified in Section 11.6 will not undergo any

significant yield until story drifts greater than those allowable

(Table 3-C) ."

Final Ballot: _8

_0

_0

0

Yes

No

Abstain

Did Not Vote

COMMENTS:

This change to the Commentary emphasizes that flat plate frames are considerabl

more flexible than other framing systems.

The ATC representative reviewed and approved the proposed ballot item which

incorporates his suggested revisions. There was one reservation expressed by

a committee member. He felt that while what was stated in the ballot item

was true for most "normal proportions" there were exceptions and suggested

that the word "will" be replaced by "should."

A112
COMMITTEE 5

A113
CHAPTER 12A

MASONRY CONSTRUCTION

Sec. 12A.1 GENERAL

This Chapter applies to new masonry construction of a structural and nonstructural

nature. It is included because a nationally applicable seismic design standard is not available. Except as portions of it may be incorporated by reference, it does not apply to the repair or rehabilitation of existing masonry nor to the construction of masonry veneers.

See Chapters 13 and 14 for repair and Chapter 8 for veneers.

12A.1.1 DEFINITIONS

The following definitions and those of Chapter 2 provide the meaning of terms

used in this Chapter.

AREA, GROSS CROSS-SECTIONAL. The total area face-to-face of masonry including cells or cavities of a section perpendicular to the direction of loading. Re- entrant spaces are excluded in the gross area unless these spaces are to be occupied by masonry by portions of adjacent units.

1

( 10-0-0 )

AREA, NET. The gross cross-sectional area at any plane minus the area of ungrouted cores, notches, cells, etc. Net area is the actual surface

area of a cross-section.

AREA, NET BEDDED. The actual area of masonry units that bear on the mortar bed with deductions for rakes and similar joint treatments. In grouted construction

the continuous vertical filled grout cores or grout spaces are included. al

AREA, NET CROSS-SECTIONAL OF HOLLOW UNIT. The gross cross-sectior*area of a section minus the average area of ungrouted cores or celluar and other spaces.

AREA, NET VERTICAL SHEAR. The minimum gross cross-sectional area at any vertical plane of hollow units, less their ungrouted cores or the mortar contact areas at head joints, whichever is less.

BOND, RUNNING. When in a wythe, at least 75 percent of the units in any trans- verse vertical plane lap the ends of the units above and below a distance not less than 1.5 inch or one-half the height of the units, whichever is greater;

the wythe, for the purpose of this document, shall be considered to be laid in running bond. (Note that for the purpose of this definition center bond or half

bond is not necessarily required to obtain running bond.) Where corners and

wall intersections are constructed in a similar fashion, they shall be considered to be laid in running bond.

BOND, STACKED. All conditions of head joints not qualifying as running bond

and all continuous vertical joints (excepting true joints such as expansion

and contraction joints) shall be considered to be stacked bond construction.

DIMENSIONS. Overall dimensions given for masonry units and walls are nominal;

actual dimensions of unit masonry may not be decreased by more than 1/2 inch from

the nominal dimension. Dimensions of grout spaces, clearances and cover given are

actual

.

EFFECTIVE ECCENTRICITY. The actual eccentricity of the applied vertical load including that caused by member deflections and thermal or other movements of connected members plus the additional eccentricity which would produce a moment equal in magnitude to that produced by the lateral loads. GROUTED MASONRY. Masonry composed of hollow units in which designated

cells are solidly filled with grout or masonry of two or more wyth«s

in which the cavities between wythes are solidly filled with grout.

JOINT, BED. The horizontal layer of mortar on or in which a masonry unit is laid.

-117-

All4
12A.1.1 Cont.

5A/1

cont

.

5A/2

5A/3

5A/4

5A/5

5A/6

5A/7

5A/8

5A/9

( 10-0

- 0 )

z :

( 10-0-0 )

( 8- 2-0 )

( 10- 0-0 ) 7

.( 10- 0- 0 )

10

( 10-0

- 0 )

JOINTS GOILAR. Tho intori o r l o ngitud in a l worti sa l joint in. a wall tetwooo . wythot. In groutad matonry eans-t ruction, i.t. Lt..tho ..irout ipaao.

JOINT, COLLAR. The vertical space separating a wythe of masonry from another

wythe or from another continuous material and filled with mortar or grout.

JOINT, HEAD. The vertical mortar joint between ends of masonry units.

JOINT, SHOVED. Produced by placing a masonry unit on a mortar bed and then immediately shoving it a fraction of an inch horizontally against the mortar

in the head joints to effect solid, tight joints.

4iOAD BEARI NG. Synonymous with Stuoodural , MASONRY. An assemblage of masonry units bonded together with mortar or grout.

(A) MASONRY, REINFORCED. Masonry in which reinforcement is used to resist

forces as well as the purpose of crack control.

(B) MASONRY, UNREINFORCED. Masonry in which reinforcement is used only

for the purpose of crack control.

MASONRY t -GROUTE D

i

—Gweteuction conforming to Soci 12Ai3 t S-4 o moot often

re fe rred to a t grout ed, brick c onstr u ction .

MASONRY UNIT. Any brick, tile, stone, or block conforming to the requirements

specified in this Chapter.

12A.1.2

N0NBEARING .

TMe term refe r s to a no nl oad - boa ri ng component , uoua lly. a. wa ll -.

NONLOAD ' B EAR INS . S ynonymous with No ng trooWra L.

NONSTRUCTlj^L . This term refers to components or systems which do not serve

in providing resistance to loads or forces other than induced by their own

weight. Walls that enclose a building or structure's interior are structrual components.

PAftf

-FAfct-f-RC IN FORCED MASONRY.—

M

as onry eowytrue-fe io n eo nfettim ng te £ ee . IDA. 3.

7

and othar appl icaole pnou-i s-iont-of this Chapter.

RCI N rORCCO MASONRY.—G ro ut ed mas e nry eans truetsan conformi ng to G ee . 12A.j.D(C) ' or-Wollow Unit Masonry conforming-to-Sec-. 12Ai3 i 6(A).—Reinforced masonry chal- 1-

a-1 s o- confo rm to o ther app lic a bl e provi s ions o f this Chap ter , including Sec. —

13A.2.2, 1 3A' .3-

. 4 r

-l gAr . 6 .3"0ind ' 12A. 6 . 4 .

REINFORCEMENT RATIO. This is the ratio of the areas of reinforcement to the gross cross-sectional area of the masonry perpendicular to the reinforcement.

SHEAR WALL is a vertical component resisting lateral forces by in-plane shear and flexure, (uni eoo <tef-i

-ned-e9-oewneref

i

11

STRUCTURAL. This term refers to a system or component which serves in providing

resistance to loads or forces other than induced by the weight of the element

itself. All portions of the seismic resisting system are structural, but not all structural components need be part of the seismic resisting system. Bracing

components, bracing systems, and walls that enclose a building or structure's

exterior are structural elements.

REFERENCE DOCUMENTS

The following standards apply to masonry materials and to the testing thereof:

-118-

All 5
i

12A.1.1 Cont.

11

( 10- 0-0 )

? Testing

^

MATERIALS AND PCDiGN

Building and Facing Brick

\

,r

STANDARD DESIGNATION

5A/9

cont

.

12(9-0-1)

Clay and Shale ASTM C62, Sand-Lime ASTM C73 Method of Test ASTM C67

Concrete Masonry Units

Hollow Load-Bearing ASTM C90 Solid Load-Bearing ASTM Cl 45 Hollow Nonload-Bearing ASTM Cl 29 Brick ASTM C55 Method of Test ASTM Cl 40

Structual Clay Tile

For Walls - Load-Bearing ASTM C34, For Walls - Nonbearing ASTM C56

For Floors ASTM C57

Cast Stone AC! 704

C21 2 , C126

13(9-0-1)

Unburned Clay

Reinforcement

Uniform Building Code Standard 24->5' 14

Reinforcing Steel Masonry Joint Reinforcement

Welding

ASTM A61 5, A61 6, A617 and A706

ASTM A82 AWS D12.1

Cement

Blended Hydraulic Cement Portland Cement and Air-Entraining

Portland Cement Masonry Cement

Lime

Quickl ime Hydrated Lime for Masonry Purposes Processed Pulverized Quicklime

Mortar

Other than Gypsum

Aggregates for Mortar

Field Tests for Mortar

Grout

Aggregates for Grout

Field Tests for Grout

ASTM C595

ASTM Cl 50 ASTM C91

ASTM C5 ASTM C207 ASTM C 51

ASTM C270 ASTM Cl 44 Sec. 12A.8.2

ASTM C404

Sec. 12A.8.2 And Western States Clay Products Standard Specifications for Hollow Brick.

-119-

A116
12A.1.2 Cont.

TeotMeg-

•— Masonry As sembl ies .-Cores

.

Mor tal* ci

' M-' fi rout Sec. 12A.7 & 12A.8

Slump Te s t f or Grout See . 12A.0:’gr (lat e of Absorption ASTM C67 73

SYMBOLS

The symbols used in this Chapter are defined as follows:

a = Angle between inclined web bars and axis of the beam.

A

g = Gross cross-sectional area, square inches.

A

s Effective cross-sectional area of reinforcement in a column or flexural member.

A = Total area of web reinforcement in tension within a distance

of s, or the total area of all bars bent up in any one plane, square inches.

b = Effective width of rectangular section or stem of I- or T-sections,

i nches.

e

l

e

2

= Eccentricity coefficient.

= Slenderness coefficient.

= Effective depth from compression face of beam or slab to centroid

of longitudinal tensile 'reinforcement, inches.

= Reinforcement diameter, inches.

= Effective eccentricity, inches.

= Effective eccentricity about the principal axis which is normal

to the length of the element.

= Smaller effective eccentricity at lateral support at ends of member (at either top or bottom), inches.

= Larger effective eccentricity at lateral support at ends of member (at either top or bottom), inches.

= Effective eccentricity about the principal axis which is normal

to the thickness of the element.

1 mb

= Modulus of elasticity of masonry in compression, psi.

= Modulus of elasticity of steel in tension or compression, psi.

= Masonry strength for development length or splice determination,

psi. (See Sec. 12A.6.3(D))

= Allowable compressive unit stress, psi.

= Compressive strength of masonry, psi.

= Brick masonry design strength, psi.

- 120 -

A117
12A.1.3 Cont.

5A/10

cont

.

5A/11

f

t = Allowable flexural tensile stress in masonry, psi.

f

y - Allowable unit stress in web reinforcement, psi.

16(9-0-1)

h - Effective height, the height or length of a column or wall used for

purposes of determining slenderness effects.

i

j

1

1

M

a

d

c

n

= Effective length of rectangular wall element or column.

= Ratio of distance between centriod of compression and centroid

of tension to the depth d.

= A dimension determined in accordance with Sec. 12A.6.3(D),

inches.

= Development length, inches.

= Minimum allowable moment capacity, inch-pounds.

= Ratio of modulus of elasticity of steel to that of masonry.

17(9-0-1) T

s

12A.1 .4

t

v

= A /bd. Ratio of the area of reinforcement to the area (bd)

.

s

= Allowable vertical load, pounds.

= Radius of gyration, inches.

= Eccentricity ratio for elements subject to bending about both principal axes.

= Spacing of stirrups or of bent bars in a direction parallel to that of the main reinforcement, inches.

= Effective thickness, inches.

= Shearing unit stress, psi.

= Allowable unit shearing stress in the masonry, psi.

= Total shear, pounds.

= A ratio as determined by Sec. 1 2A.6.3(D)1

.

CRITERIA FOR MASONRY UNITS

Masonry units shall be of a type, quality, and grade consistent with the applicable provisions and intent of the referenced documents considering:

The intended usage such as structural or nonstructural

.

The surrounding enviroment such as severe frost action in presence

of water, contact with the ground, exposure to the weather and/or enclosure within a building.

Type, quality, grade, and any similar additional special requirements of this Chapter or Chapter 12 for masonry units, all as applicable, shall be indicated on the desian documents.

- 121 -

A118
12A.1 Cont.

12A.1.5 INITIAL RATE OF ABSORPTION

At the time of laying, burned clay units and sand-lime units shall have a rate of absorption not exceeding 0.025 ounce per square inch during a period of one minute. Test procedures shall be in accordance with ASTM C67-73. In the absorption test the surface of the unit shall be held 1/8 inch below the surface of the water. Water content

shall be that of the units to be laid, i.e., the units shall not be dried.

5A/11

cont

.

18 (9-0-1)

12A.1.6 «M«* MASONRY UNIT SURFACES FOR GROUTED MASONRY

Masonry units for awrfoncod and u nw&inforGoa grouted masonry shall have all surfaces to which grout is to be applied capable of adhering to grout with sufficient

tenacity to resist

a

ysheari no stress.ef 100 p»i after curing 28 davc . Tests, when required.

shall conform to Sec. 12A.7 and 12A.8.3.

12A.1.7 RE-USE OF MASONRY UNITS the required

Masonry units may be re-used when clean, whole, and in conformance with the requirements of this Chapter and those of the applicable reference documents. Conformance must be established by tests of representative samples.

12A.1.8 CAST STONE

Every cast stone unit more than 18 inches in any dimension shall conform to the requirements for concrete in Chapter 11.

12A.1.9 NATURAL STONE

e Natural stone shall be sound, clean, and in conformity with other provisions of this Chapter

12A.1 .10 GLASS BUILDING UNITS 5A/12 19(9-0-1)

Glass block shall have unglazed or satisfactorily treated surfaces to allow adhesion on all mortared faces. Units shall be constructed so that a minimum panel thickness of i nches can be obtained at the mortar joints.

3.0

12A.1.11 GLAZED AND PREFACED UNITS

Glazed and prefaced units shall conform to the physical criteria for unglazed

and unfaced units required by this Chapter and Chapter 12 in addition to any special

requirements desired for the exposed finish. Surfaces receiving mortar and surfaces to be grouted shall be unglazed.

12A.1.12 WATER

Water used in mortar, grout, or masonry work shall be clean and free from injurious amounts of oil, acid, alkali, organic matter, or other harmful substances.

5A/13 20

(9-0-1)

4 3Ail>W SH RI NKAGE OF CONCRETE UN ITS

C ene ne te mooowry unite ucod' fo r otruetural pu npooeo o hoi 1 ha*c a max i mum li

s hrinkag e of 0.065 percent from . the sa t u r a t ed t o the o ven-d ry re ndi ti o n .

- 122 -

A119
12A.1 Cont.

5A/14

5A/15

21

(5-3-2)

22(9-0-1)

12A.1.14

Chapter 12

CEMENT C476

Cements for mortar are limited to those allowed by ASTM CS70, this Chapter and except masonry cement shall not be used for grout.

Approved typoo of plaotioiaing a g ento maybe added to po etla n d eoment Type I or Type M - in . She manufactur i wg p i»ooofiCi ) but not i w. exe e oc o4

12 percen t of the to tal v o lume .—Alootie or1 waterproofe d eeme nta ao ma nufa ctured- -shall meet the ro g ui romonta for Portland oeroert ex cept

m—

r

at pac t to the- 1 invit a tion s on inso l ub l e res id ua, a ir-entra inme nt , and add itions Gubsoqeoot"te-ea4 ci ea t1<HH

Gorton to for g rout sha ll bo Typo I , IA , II; 1 1

A

, III , IIIA , ee—¥-pere4- earnest , ar Typa IS ,

1 S-A , I S ( MS ) , 1 S-A ( MS ) , IB , er . l P-A blended hyd raulic oanen

12A.1.15 LIME

23(9-0-1)

b

-i me pa tty Ghal-1 bo. oi ade from , gus oklisto on - hydra tod Itnt ei if ma oe »rem ot oe*

ttva.n-.p rac a t t ad pulveri sed . q u ick! ima, tha lima sha ll be-sleked a nd than sc ree ned thro u oe a Ne . 1 6 me sh oio u oi—Af-t-er—

s

l .a 4a*vp.-and oonooning, and befo re uoi ogyit s hall be oter a e a n*

protected nnr Inrr—t-hin, in ria ii r Lime for mortar and grout is limited to those allowed by ASTM C207

P reeeaaca pu ivc ngce qu ie xnme aooti1 og'-ot-oxea ter net less t h a n *0 ho urt'ang- shall ba. gaol whan atari.

12A.1.16 MORTAR property or proportions

Mortar shall be prepared in accordance with'ei ther-** the*procedures given

dal aw i in ASTM C270.

a The Property Speei fica tions of ASTM G270 ma y bo uood w ith . acoootaoi 1 it r

booed upon the- properti e s. of both the ingr ed ients a na G a mc lo s af mar tar mixed and tooted in the laboratory usnng the prop ortions ana ma terials

propos e d fo r- ooe: • Comp reo&4v o st rengt h s o hall ret- he l e cs-- t h a w requi reg by-Tafrl o 12A 1A .

24

( 10-0- 0 )

The Rnepe rti e n S pas i fi ca ti enc of AS TM C270 may da us od witn aea ea t a bil ity daood upon the properties of the--'i

n

q rooi onto , the wator retention of

labo r ato ry mixed and t a st ad sampl es, a n d tha p reportiono of the ing red i ents sumna ri aed in Tadl e 1 2A- 1 8.

Where mortar colors are used or where minimum compressive strengths are required

for mortar used in the work, only the Property Specifications shall be used. Field tests

shall conform to Sec. 12A.7 and 12A.8.2.

Where the source or the proportions of ingredients for mortar, classified in accordance with the Property Specifications, are intended to be changed during the course of the work, acceptability of the new mortar shall be reestabl ished in accordance with

ASTM C270.

ASTM C270 Types 0 and K mdrtar shall not be used.

Maso nry u n its uo ad i n foundation walla a nd footingc shall be laid up in- Type S

-Cype-H. mort a r , i ce See, l iA .j a nd C h ap t er 12 f a r furth e r limita tions.

-123-

A120
12A.1.16 Cont.

25

( 10-0- 0 )

26(9-0-1)

Admixtures shall be added only after approval by the Regulatory Agency.

Coloring ingredients shall be limited to inert mineral or inorganic synthetic compounds not exceeding 15 percent of the weight of cement or carbon black not exceeding 3 percent of the weight of cement.

To maintain plasticity, mortar may be retempered with water by the method of

forming a basin in the mortar and reworking it. However, any mortar which has b e eeme

hepeh sha ll ne t be wtad in the werk. hardened or stiffened due to hydration of rh? cement shall not be used.

" 12A.1.17 GROUT

(A) PROPORTIONING. Grout shall be proportioned by volume and shall have sufficient water added to produce consistency for pouring without segregation. Aggregates

shall conform to ASTM C404 except that larger size coarse aggregate may be used in large

grout spaces where approved by the Regulatory Agency.

EXCEPTION:

Grout may be proportioned by weight when weight- vol ume relationships are established and periodically verified.

(B) TYPE. The requirements for coarse and fine grout shall be as follows:

1. Fine Grout. Fine grout shall be composed, by volume, of one part cement, to which may be added not more than 1/10 part hydrated lime or.. l.wae ' , and 2-1/4 to 3 parts of sand.

2. Coarse Grout. Coarse grout shall be composed, by volume, of one part of cement, to which may be added not more than 1/10 part hydrated lime om 1 ' two putftjn two

to three parts sand, and one to two parts gravel. Larger proportions of gravel may be used

in large grout spaces where approved by the Regulator Agency.

27

( 10- 0- 0 )

Coa rso g rout may be utaa in g routs pa c e

id»h a nd in g rout fi Hod- coil grouted moconry 3 i wc Xe:

s paces

o gwa ro io&hdc w-i th a loact dimension of i inohos i tooo-t

' ioo ha v i ng a w a re a of I S5A/16

5A/17

5A/18

pa eo" exceeds 6- yowt- ofx»1 4""de' used whore the looot din wwerc otherw ise- requi e etit of t he g rout

(C) CONSISTENCY. Grout shall have a consistency, considering the methods

of consolidation to be utilized, to completely fill all spaces to be grouted without segre- gation »ew««p*— be— 4-rs—we+tee— wwhoo fee fi na . grea t ar 9 inc hes far aearte. grea t

(D) ADMIXTURES. Admixtures shall be approved by the Regulatory Agency.

(E) MEASURING AND MIXING. Materials for grout shall be measured in suitable calibrated devices. After the addition of water, all materials shall be mixed for at least three minutes in a drum tree bats h Ymixer . Mixi n g oqui pmont ana e meeed uroo shall eredaa o gne ut with- the a ni-farmity r equ ired fa r saaa ret e la y A S TM tSd JT~L_ mechanical batch

(F) STRENGTH. Grout shall attain the minimum compressive strength required by

design or required to obtain the prism strength required by design, but shall not be less than 2000 pounds per square inch at 28 days. The Regulatory Agency may'require field tests to verify the grout strength. Such tests shall be made in accordance with Sec. 12A.7 and 12A.8.2.

-124-

A121
12A.1 .17 Cont.

30(10-0-0)

5A/1S

cont

.

31(9-0-1)

5A/19

5A/20

5A/21

(G) ALUMINUM EQUIPMENT. Grout shall not be handled nor pumped utilizing aluminum equipment.

Aluminum equ ipmen t may be used if it

ehe ne will be no deleterio u s offoot. a

)f» be demono tea oed tha t the obnong th of t h e gwa ipeoifi sa lly app roved fey the Regu l a to ry Age nt

12A.1.18 REINFORCEMENT

Reinforcement over one-fourth inch (No. 2) in diameter shall be deformed bars.

'Sec. 12A.2 CONSTRUCTION

the tawe-of- lay i ng all- masonryu

nit s s ha ll be cl ea n a nd free of dust Burned

Storage, handling and preparation at the site shall conform to the

following requirements.

Masonry materials shall be stored so that at the time of laying the materials

are clean and not damaged.

Concrete masonry units shall not be wetted unless otherwise approved.

Quifat e s o f all ma soni y units fen -grou ted c o ns tr uction ai H ie time of haying snai l

feo-^apa t»j-e-w»f d eve loping the-- noquiped bond w* feh g nout jo specified 4n Se e . IQA.l. e .—

12A.2.1 JOINTS

All units shall be laid with shoved mortar joints. Solid units shall have all head and bed joints solidly filled. Except fon ca v ity wa lla , spaces to bo greeted

prov ided ' 4 n-Seci

I-3A-ie. 3 i"a4 1 wall - joints , colla r j oin t s ; and joi nts betwee n wythea shall ba so li d ly fill ad. wai i' joinssi' •unless otherwise approved.

All hollow units shall be laid with Aw ll face shell bed joints and head joints

filled solidly with mortar for a distance in from the face of the unit not less than the thickness of the face shells unless more stringent construction is required by this Chapter, Chapter 12, or by design. Cross webs and end shells of all starter courses shall be bedded on mortar.—TdiG app lioo to unite -1 a id'd n founda ti o n s an. fl ee r s l a bs a r s imil a r , a nd a ll eaurset of pi e rs, . rolu anns, .anrl pil a st er s . unless otherwise specified.

Gonenoto abutting c true sural masonry ouch a e at starto e wa44- intersettiei

1 OA 0 —*rW

Unless

4wye -a n pro v ided; v ortie a l j o int s sha ll bo idored-' to b o otookod bo ndi Surfaces in contact with mortar or grout shall be clean and free of

laitance, debris, or other deleterious materials.

Except as provided for firebrick or otherwise restricted, initial bed joint thickness shall not be less than 1/4 inch nor more than 1 inch; subsequent bed joints shall not be less than 1/4 inch and not more than than 5/8 inch in thickness.

12A.2.2 BOND PATTERN

All bed joints shall be horizontal and all head joints between adjacent units

shal 1 be vertical

.

EXCEPTIONS:

1. Rubble stone masonry joints may vary from the horizontal or vertical

.

2. The joints in arches and similar construction may vary from

the horizontal or vertical.

-125-

A122
12A.2.2 Cont.

3. The joints in other masonry construction may vary from the horizontal or vertical provided the construction is approved

in accordance with Sec. 1.5.

36

( 10- 0-0 ),

37

( 10- 0-0 )

(A) REQUIREMENTS. Adjacent wythes shall be bonded to each other in accordance with the applicable provisions of Se e . IQA. 'g

-

. 1 a nd Sec. 12A.3.

All wythes of all masonry walls and all corners and wall intersections

shall be laid in running bond except where true joints such as expansion and contraction

joints are provided and except as follows. . . unrein forced-. -masonry

Where not prohibited in Chapter 12 or this ChapterjAStacked bond^may be used with one of the mechanical bonding devices indicated in Sec. 12A.2..2 (A) 1, 2, and 3 below?

the foil aw ing;

fee unre+wfe^eed mason ry the mechanical bond- sha ll be pntnwi dod by ono of

1. Not less than two continuous corrosion-protected wires conforming

to ASTW A82 in bed joints spaced not over 16 inches vertically. The wires shall provide a minimum reinforcement ratio of 0.00027 or each shall have a minimum cross-sectional area of 0.017 square inch, whichever is greater. At corners and intersections the wires shall be bent and shall be continued beyond the bend. No splices of continuous wires shall occur within 12 inches of the bend. Splices of the continuous wires shall be at least 12 inches

in length and splices of alternate wires shall be staggered.

2. Where only the corner or intersecting joints are of stacked bond construction these joints may be bonded by 1/4-inch diameter steel rods, bent into a rectangular shape so that two legs cross the joint, laid in bed joints spaced not over 16 inches vertically. The rods shall extend a distance equal to the length of the masonry

units, but not less than 6 inches, beyond each side of the joint. For masonry construction with other than hollow units, corrosion-protected steel straps having the same total area may be used in lieu of the rods. The ends of the straps shall be bent up 2 inches or cross pins for anchorage shall be provided.

For brick masonry designed in accordance with Sec. 12A.6.2 where

the intersecting walls are regularly toothed or blocked with 8-inch maximum offsets, the bonding may be provided with metal anchors. The anchors shall be 1/4 inch by 1-1/2 inch with ends bent up at least 2 inches, or with cross pins to form anchorage. Such anchors

shall be at least 24 inches long, and shall be placed in bed joints spaced not over 48 inches vertically.

For nonstructural masonry the mechanical bond at intersecting joints, when required, shall be provided by corrosion-protected steel ties or clips at least 7/8- inch wiae and not less than 16 gage or their wire equivalent, embedded in the bed joints,

extending 3-inches minimum each side of the continuous vertical joint, placed not over 32 inches vertically.

3. For cavity walls the provisions of 1 and 2 above apply to each wythe.

38(6-0-4)

Ter s ta e hed bond rei n forced grouted or noinfoncod hollow unit moconry t ooo

C hapte r Kh—rer s ta e ked herd pa rtially re trfcreed masonry, see S ee . I SA. 3. 7(A) an d G h apten

13i For o hoar w»Mo ooe ano Ghaptor 13—

12A.2.3 CORBELING

39(9-0-1)

Go rhelo in u nroi nfo rcod maoonny ma y bo b u ilt e nly into soi id^na sonny wallo

i nc he s o r wore in thiok n osoi Gorbolc i n partially rei nfo rc ed ma sonry may H e b uid t an ly inte ma Goony wa llo 12 inches or mono in thickness unices the constructio n provi d ed for the

-1 26-

A123
12A.2.3 Cont.

39cont

.

foneeri eoobci 8 sholl fro"* Meade*1 The slope of corbelling (angle measured from the horizontal to the face of the corbeled surface) shall not be less than 60°. The maximum horizontal

Zrlt rtTS

th

!

C° rbel fr°m the Plane ° f Che wal1 sha11 «°t exceed one-half the vythe thickness for cavity walls one one-half the wall thickness for all other walls

12A.2.4 REINFORCEMENT

40

( 10-0- 0 )

RcinforeawenO sna il eowfoww eo t he oequi 1‘eme wfrs <»f t h ie -Se eti iow i

> Reinforcement shall conform to the requirements of this Section.

All netal reinforcement shall be free from loose rust and other coatings

that would reduce bond to the reinforcement.

(A) BAR SPACING. The minimum clear distance between parallel reinforcement,

except in columns, shall be not less than the reinforcement diameter nor 1 inch except that lapped splices may be wired together. The center-to-center spacing of bars within a column

shall not be less than 2-1/2 times the bar diameter. In addition to the preceding, the minimum clear distance between parallel reinforcement embedded in coarse grout shall not be less than 1-1/3 times the maximum aggregate size.

41

( 10-0-0 )

or (B) SPLICES. Splices in reinforcement may be made only at approved locations awe as indicated on the approved design documents. Splices shall conform to the provisions

of Sec. 12A.6.3(D)7.

(C) EMBEDMENT AND COVERAGE. All reinforcement shall be completely embedded in mortar or grout. Joint reinforcement embedded in mortar joints shall have not less than 5/8-inch mortar coverage from an exposed face and 1/2 inch from other faces. All other reinforcement shall have a minimun masonry coverage of one bar diameter, but not less tnan

3/4 inch except where exposed to water, weather, or soil in which case the minimum coverage

shall be 2 inches. See Sec. 1 2A .3.5(C) and 1 2A .3.6(A) for minimum grout coverage.

(D) SIZE LIM^TIONS. Longitudinal wall bars and other longitudinal bars shall

be limited to deformed bars, #3 minimum and #10 maximum, when used in reinforced or partially

reinforced masonry construction.

EXCEPTIONS:

1. Number 11 bars may be used provided the grout cover, measured from masonry units to reinforcing bar, including

areas at splices is at least 1-1/2 inches.

2. The size limits do not apply to masonry joint rei nforcement

or column ties. See Sec. 12A.6.3(E)2 and 12A.6.3(F)2.

(E) WELDING. Welding of reinforcement shall conform to AWS D12.1. Rein- forcement to be welded shall conform to the chemical requirements of ASTM A706 or the chemical constituents shall be verified.

12A.2.5 TEMPERATURE LIMITATIONS

No maoonny s hall 'bel a i d when the i ampa r a t u ra s f

~

. ho aw iGi d o a im G

c

- u nl esi app rov ed jnothadfc a r e u s ed daring scn i tr us ti e n t s p

re v ent dam a ge to tho masoneM,— Suc h me thods inelu ri e protec tio n at t he ma sonry

f ar a peri od o f at l east 2 4 nouro wne-e- Type I H Por tla nd eemen t is used i n morta r a nd gro u t a nd * or a p er iod of at least- 6-mou”'; whono othon oanonto a mo uood.—Ma terials to bo uoofl ' »nd- matoni al o to bo built upon oha t i - o i free r oom ioo and onew. Cold weather construction shall conform to the requirements of

"Recommended Practices and Guide Specifications for Cold Weather

Construction" by the International Masonry Industry All-Weather Council.

When the ambient air has a temperature of more than 90° F in the shade, and has

a relative humidity of less than 50 percent, protect newly erected masonry from direct exposure to wind and sun for 48 hours after installation.

-127-

Al24
12A.2 Cont.

5A/22

cont.

5A/23

5A/24

5A/25

(1

1

)

44(7-1-2)

45

( 10- 0- 0 )

12A.2.6 ANCHORAGE

Masonry walls shall be anchored to components providing lateral support as required by Sec. 3.7.6. Nonstructural walls required to be separated from the structural system shall be provided with anchorages which will permit relative movement between the wall and the structure as required by Sec. 3.8.

12A.2.7 BOLT PLACEMENT

Edge distances and center-to-center spacings shall not be less than required by Table 12A-6.

In grouted construction, all bolts shall be grouted in place. The bolts shall be accurately set w ith tempi atoo on by a pproved eq uiv a lent mo a ns and held in place to prevent movement. Grout coverage shall be as required for reinforcing bars of equivalent

size.

In ungrouted construction, bolts shall be securely embedded in mortar except

that for hollow unit masonry the cells containing bolts shall be grouted or mortared solid. There shall be at least 1/4 inch of mortar between bolts asnd masonry units for bolts set in mortar.

In cavity wall construction the wall shall be made solid at bolts for at least

six diameters each side of the bolt.

Vertical bolts at the top of and near the tends of reinforced masonry walls

shall be set within hairpins or ties located within -SrS» i nches from the top of the wall.

See Sec. 1 2A .6.3(F) and 12.4.1(B) for bolts at the top of piers, pilasters, and columns.

12A.2.8 PENETRATIONS AND EMBEDMENTS

No conduits, plumbing, and similar embedments, holes, sleeves, chases, recesses, or other weakening construction are permitted unless indicated on the approved

plans. See Sec. 12A.4.4 and 12A.4.5.

12A.2.9 SUPPORT BY WOOD

Wood members shall not be used to support any permanent loads imposed by masonry construction except as provided in Sec. 9.5.2.

Sec. 12A.3 TYPES OF CONSTRUCTION

The types of masonry construction in Sec. 12A.3.1 through 12A.3.7 may be used for structural or nonstructural purposes and the type of masonry construction in Sec. 12A.3.8 may be used for nonstructural purposes subject to requirements of Chapter 12 and this Chapter.

12A.3.1 UNBURNED CLAY MASONRY

Unbu med e lay ma sonry i s t hat farm ef eo ns tnueti en made- with u nbu rw e d elay

unido i Mo s o nny "Of unbunnod clay units shall not bo n e ed in a ny bui' ldi nq mono than ono stony in hoi g hti—AH footing wa4 io whic h- cuppent masorwy-e f unbumed e lay OHtona to a n el eva tion no t les s tharv .fr.. Awohos above tho a dj a cont^nowvd- »t a ll . . po. >n.t &.. Unbumed clay masonry is that form of construction made with unbumed

clay stabilized with emulsified asphalt. Such units shall not be used in any building more than one story in height. All footing walls which support

masonry of unburned clay units shall extend to an elevation not less than

6 inches above the adjacent ground at all points.

-128-

A125
12A.3 Cont.

12A.3.2 STONE MASONRY

Stone masonry is that form of construction made with natural or cast stone with

all joints thoroughly filled.

In ashlar masonry, bond stones uniformily distributed shall be provided to the extent of not less than 10 percent of the area of exposed faces.

Rubble stone masonry 24 inches or less in thickness shall have bond stones with

a maximum spacing of 3 feet vertically and 3 feet horizontally, and if the masonry is of greater thickness than 24 inches, shall have one bond stone for each 6 square feet of

wall surface on both sides.

SOLID MASONRY

I

solid concrete or clay masonry units

brie k, ecwere t e b H e ki ei* se l iH l ead bea wi n g oo w c eotc

laid contiguously in mortar.

The bonding of adjacent wythes in bearing and nonbearing walls shall conform

to one of the following methods:

12A.3.3 46

5A/25

cont

.

• HEADERS. The facing and backing shall be bonded so that not less than 4 percent of the exposed face area is composed of solid headers extending not

less than 3 inches into the backing. The distance between adjacent full length, headers shall not exceed 24 inches vertically or horizontally. Where backing consists of two or more wythes, the headers shall extend not less than 3 inches into the most-distant wythe or the backing wythes shall be bonded together with separate headers whose area and spacing conform to this Subsection.

• METAL TIES. The facing and backing shall be bonded with corrosion-resistant

unit metal ties or cross wires or approved joint reinforcement conforming to the requirements of Sec. 12A.3.4 for cavity walls. Unit ties shall be of sufficient length to engage all wythes, with ends embedded not less than one inch in mortar, or shall consist of two lengths, the inner embedded ends of which are hooked and lapped not less than 2 inches.

Where the space between metal tied wythes is solidly filled with mortar

the allowable stresses and other provisions for masonry bonded walls shall apply. Where

the space is not filled, metal tied walls shall conform to the allowable stress, lateral support, thickness (excluding cavity), height, and mortar requirements for cavity walls.

12A.3.4 CAVITY WALL MASONRY

Cavity wall masonry is that type of construction made with brick, structural clay tile or concrete masonry units, or any combination of such units in which facing and backing are completely separated except for the metal ties which serve as bonding.

In cavity walls neither the facing nor the backing shall be less than 4 inches

in thickness and the cavity shall be not less than 1-inch net in width nor more than 4 inches in width. The backing shall be at least as thick as the facing.

EXCEPTION: Where both the facing and backing are constructed with solid units,

the facing and backing may each be 3 inches in thickness.

-129-

A126
12A.3.4 Cont.

5A/26

5A/27

The facing and backing of cavity walls shall be bonded with 3/16-inch-diameter

steel rods or metal ties of equivalent strength and stiffness embedded in the horizontal joints. There shall be one metal tie for not more than 4.5 square feet of wall area for cavity widths up to 3.5 inches. Where the cavity exceeds 3.5 inches net in width, there

shall be one metal tie for not more than each 3 square feet of wall area. Ties in alternate courses shall be staggered and the maximum vertical distance shall not exceed 36 inches. Rods bent to rectangular shape shall be used with hollow masonry units laid with

the cells vertical; in other walls the ends of ties shall be bent to 90-degree angles to provide hooks not less than 2 inches long. Additional bonding ties shall be provided at

all openings, spaced not more than 3 feet apart around the perimeter and within 12 inches of the opening. Ties shall be of corrosion-resistant metal, or shall be coated with a corrosion-resisting metal or other approved protective coating.

J2A.3.5 GROUTED MASONRY -MULTI/WYTHE WALLS

Gnoutod th a t fown of which inte ri or jainK .a f ma s a nny stwfotion mo do with twie to filled t>yi pawning g nout thoeoi isolid oo norot q. tho won k p wog eooooo i Only Typo H-an- Typo S montap shall Oo uootki—Wh e n we i nfo we e d iwaoeowdci wee wit h ouboootiofr- (G) bolow matcnry s ha ll be c l ass ifi ed at reinforced grou ted maso nry^

Grouted multi-wythe is a form of construction in which interior joints

between wythes are filled with grout. Only Type M or Type S mortar shall be used.

Tooth i ng af ma se wy wall a design ong inoon- annimym .

hi t es t a n d anly at a pp navod loc a t i p g iya itted o n ly w h en designed a nd detailed by the

[looking - to be hoi d to a

dmuting and nr

r' p-m-nHm-nr mnfninn tn thn nn au incmontG o?

50

( 10-0 -0 ) Grouting procedures for the space between wythes shall conform to the

requirements given below. Coarse grout may be used in grout spaces 2 inches

or more in width. Coarse grout shall be used where the least dimension of

the grout space exceeds 5 inches..

5A/28

51

( 10-0 - 0 ),

52

( 8- 0- 2 )

53

( 10- 0-0 )

(A) LOW LIFT. Low lift grouted construction procedures are as follows:

/. AH uni te

" i wthe twe out er t ienc snoll bo loi4with full shovod he a d and bod mortar joints. [-Masonry headers shall not project into the grout space.

!•/. All longitudinal vertical joints shall be grouted and shall not be

less than 3/4 inch in thickness for unreinforced construction and 1-1/2 inches in width

for reinforced construction, but not less than that requred to maintain grout thicknesses

between masonry units and reinforcement. In members of three or more ^A^wa^in thickness, interior bricks shall be embedded into the grout so that at least 3/4 inch of grout sur- mav

rounds the side and ends of each unit. Floaters ah*44.|be used where the grout space

'

exceeds 5 inches in width. Th o thioknoco of g rout botwoon i masonny uni to and floatero shal l be not Tort 1 All grout shall be puddled w ith » g naw t. stick. immediately after pouring.

[ wythe

wythe 2./, One exteriorities may be carried up 18 inches before grouting, but the other exteri op tion shall be laid up and grouted in lifts not to exceed six times the width

of the grout space with a maximum of 8 inches.

3./. If the work is stopped for one hour or longer, the horizontal construction joints shall be formed by stopping all tiesa^at the same elevation and with

the grout 1 inch below the top. wythes ~ (B) HIGH LIFT. High lift grouted construction procedures are as follows:

-ii

All u n i to i n tho two tie wo ohoi l bo laid with full head and bod

-130-

A127
12A.3.5 Cont.

5A/28

cont

.

5A/29

5A/30

5A/31

55

( 10-0- 0 )

57

( 10- 0- 0 )

58

( 10- 0- 0 )

59(9-0-1)

be not less than No

wythes

The twoj^Wero shall be bonded together with wall ties. Ties shall

9 wire in the form of rectangles 4 inches wide and 2 inches in length

less than the overall wall thickness. Kinks, water, drips, or deformations shal 1 not be permitted in the ties. Approved equivalent ties may also be used. One tien](of the wall

shall be built up not more than 18 inches ahead of the other tier. Ties shall be laid not

to exceed 24 inches on center horizontally and 16 inches on center vertically for running

bond and not more than 24 inches on center horizontally and 12 inches on center vertically

for stacked bond.

2* \. Cleanouts shall be provided for each pour by leaving out eee ry e th e r

wythe

unitsin the bottom tier of the section being poured, or by cleanout openings in the foundation. During the work, mortar fins and any other foreign matter shall be removed from the grout space. b y mea ns 9* a h ig h- pwessu ee j et stream of wate r ; a ir j e to; o r e th er a e p ro v oa proood e noo i Ma t e ri a l f a lling to tho bottew-of tho grout opoee- oholl be t h o roug h ly r omov ee i The cleanouts shall be sealed after inspection and before grouting.

2 2. ^ the grout space (longitudinal vertical joint) shall not be less than

-S* inches in width and not jjess than the tfiickness required by the placement ot steel with

the required clearances and shall be poured solidly with grout. Haoewry walls sh a ll ou re at iojc u-nhroo da y s te .ga in.

s

trong Tin b ofe ro gno e t - ifi paw ned.

EXCEPTION:

If the grout space contains no horizontal steel, it »ay-h c redu sad t e 2 man at, shall be at least 3 inches.

4. Xu Vertical grout barriers or dams shall be built of solid masonry

across the grout space the entire height of the wall to control the flow of the grout horizontally. Grout barriers shall be not more than 30 feet apart. Unless o t i

oe jc occurs at the harrier, Reinforcement, if it is present, shall be continuous through tne barrier. In work that is part of the seismic resisting system, the grout barriers shall be constructed so as to form keys, at least 3/4-inch deep, with the grout except that construction providing equivalent irregular surfaces may be used where appropriate.

5- is. Grout shall be a plastic mix suitable for pumping without segregation

of the constituents, and shall be mixed thoroughly. Grout shall be placed by pumping or

by an approved alternate method and shall be placed before any initial set occurs.

6. Grouting shall be done in a continuous pour, in lifts not exceeaing

6 feet. The full height of each lift shall be consolidated by mechanical vibrating during

placing and reconsolidated after excess moisture has been absorbed, but before plasticity

is lost. The grouting of any section of a wall between control barriers shall be completed

in one day with no interruptions greater than one hour.

7

.

Inspection during grouting shall be provideo in accordance with Sec.

1 2A .

7

4 howe ver ; -t ho work' Gha ll not qua lify for the s tresses eetitl ee,

" Saes i a l Inspection 11

, unless ful ly ' inspected per See; 1i 6i S; 1i Bi 4, and- 4 g,a,t I .

(C) REINFORCED CONSTRUCTION. All r equi red rei n forc emen t e x ce p t maso nry joi n t noi nforoomont s od'Sekwnn tioc conformin g to tho paragraph bolow snell be- emhoadefr ' reinforcement shall be embedded in mortar or grout. All vonti < shall be held firmly in place during grouting by a frame a n suitable-*^**

All h o riaontal noi nforccmont in the'

g

rout O

' paco sha l 1 be tiod to tho vortical

4- rei nforcement

l e nt devi ces

.

hofe ne ame nt or h eio i» place during g roat>n9' t>y- oqui' val 30t' mea nt ,

-131-

A128
12A.3.5 Cont.

62

( 10-0-0 )

5A/32

5A/33 63(7-3-0)

5A/34 64

( 8- 1- 1 )

65

( 10- 0- 0 )

66

( 10- 0- 0 ) 5A/35

67

( 10- 0-0 )

The thickness of mortar between masonry units and reinforcement shall not

be less than 1/4 inch, except that where allowed 1/4 inch bars or less may be laid in horizontal mortar joints at least twice the thickness of the wire diameter. See Sec.

12A. 6.3(F) and Chapter 12.

The thickness of grout between masonry units and rei nforcement shall not

be less than 1/4 inch where fine grout is used nor 1/2 inch where coarse grout is used. See Sec. 12A.1.17 and 12A.2.4.

See Chapter 12 for stacked bond limitations.

12A.3.6 HOLLOW UNIT MASONRY

Hollow unit masonry is that form of construction made with hollow masonry units made from concrete, burned clay, or shale.

Where two or more hollow units are used to make up the thickness of an unreinforced wall, the stretcher course shall be bonded at vertical intervals not exceeding 34 inches by lapping at least 4 inches over the unit below or by lapping at vertical intervals

not exceeding 17 inches with units which are at least 50 percent greater in thickness than

the units below; or by bonding with corrosion-resistant metal ties conforming to the requirements for cavity walls. There shall be one metal tie for not more than each 4.5 square feet of wall area. Ties in alternate courses shall be staggered, and the maximum

vertical distance between ties shall not exceed 18 inches, and the maximum horizontal distance shall not exceed 36 inches. Walls bonded with metal ties shall conform to the requirements for allowable stress, lateral support, thickness (excluding cavity), height, and mortar for cavity walls.

Hollow unit masonry construction, where certain cells are cont inuous,] with I 1

1 1 II II l~l III

LI I'l 1 1 1 r anrt rei nfnrromant in accordance with Snh<;prt mu I

1 ll I Inhiw is embedded therein cK!>1 j“~ -"•'nfm-red hoi In i in Reinforced hollow

unit masonry shall generally be one wvthp~i^**g?*r;i° <:~ Tf constructed of more than one

wythe, each wythe hill In ||| . nineil i i~rpinfr rlrniTHl m wall or t he wythes shall be bonded tnnpthpr |iy nw'iTTr mi I by the Regulatory Agency. ThT^TTiTiTtTH t h n 1 1 hr designed

wrrHTgsshan act as a unit. 1

GROUTII1G PROCEDURES

(A) RE I N FORCED CONSTRUCTIO N ! Units shall be laid with mortar in accordance

with Sec. 12A.2.1. O n ly Typoo M a n S mart a r s h a ll be used . Where only certain vertical cells are to be filled, the walls and cross webs of these cells shall be full bedded in mortar to prevent grout leakage. Vertical cells to be filled shall have vertical align- ment sufficient to maintain a clear, unobstructed continuous vertical cell measuring not

less thanrl inches by 3 inches. If walls are battered or if alignment is offset, the S, inch by 3|inch clear opening shall be maintained as measured from course to course. 1 1/2

Overhanging mortar fins projecting ma re th a n thfr -uhioWneso of the ma rta r

j a int into the grout space shall be wwoful 1 y removed. aG tho work p no g noeGot. in. a m anne r that proven tG the ma rt a r frem f a Hw». ta.. the b e ttom wirf the c a l Is.

1/2

Coarse grout may be used in hollow masonry units having an area of 10 square inches with a least dimension of 3 inches. Coarse grout shall be used

when the least dimension of the grout space exceeds 5 inches and where otherwise

required.

Except as provided in Chapter 12, all reinforcing except ties and masonry

joint reinforcement, where permitted, shall be embedded in grout. Longitudinal horizontal reinforcing shall be placed in bond beams u ni t; t except as permitted for masonry joint rein- forcement. 1?A. 6.3(F) and Chapter 17,

Vertical reinforcement shall be positively held in position at top and bottom and at intervals not exceeding 192 diameters of the reinforcement.

-132-

A129
12A.3.6 Cont.

68

( 10 -0-0 )

The thickness of the grout between the masonry units and reinforcing shall be a minimum 1/4 inch for fine grout and 1/2 inch for coarse grout. See Sec. 12A.1.17 and 12A.2.4. See Chapter 12 for stacked bond limitations.

Grouting procedures shall conform to the requirements given below. When grouting is stopped for one hour or longer, horizontal construction joints shall be formed

by stopping the pour of grout at least 1/2 inch above or below a bed joint.

1. Low Lift. Low lift grouted construction procedures are as follows:

5A/35

cont

.

a. Hollow units shall be laid to a height not to exceed 4 feet 8 inches prior to filling cells with grout; grouting shall not be in lifts greater than 4 feet.

b. All cells containing reinforcement shall be filled solidly with

grout. All grout shall be consolidated at the time of pouring by puddling or vibrating. When the grout lift exceeds two feet, the grout shall be reconsolidated after excess moisture has been absorbed, but before workability is lost.

c. Reinforcing shall be in place prior to grouting.

2. High Lift. High lift grouted construction procedures are as follows:

5A/36

5A/37

71

( 10-0-0 )

5A/38

WfHtS Hnay bo laid up 8 i nofHW -frig no* than the-wtal 'N eiqnt of t w o grout lift which sha ll not ' 0*cood I S foot for w alls 8 Inc hes . oawinal tn i

a

lr.

n

a a 4 foo t fo r thiwiar wi lls .

b. Cleanouts shall be provided in the foundation or by oni sti

n

g in the

face shells in the bottom course of each cell to be grouted . to facil i tat e e l e a nc m wnfer11 bo a GGomp lishod by of a hi g ft p* jot ot ream of wato w i ot he r a pp ro v ed procedures*—

N

otorial fo i li n g to t he bee dem o t t he g re ut opaee a n d other oopr»o—

shall b 0 ' thorou ghly rema w ad. Debris in the grout space shall be removed.

c. The cleanouts shall be sealed after inspection and before

grouting. Grout shall be a workable mix suitable for pumping without segregation of the constituents and shall be mixed thoroughly. Grout shall be placed by pumping or by an approved alternate method and shall be placed before initial set or hardening occurs. p

and may be done

d. Grouting shall be done in a continuous pourJ(in partial lifts.**

to av e i d bl owou t o£ u nits .

The full height of each lift shall be consolidated by mechanical vibrating during placing, and reconsolidated after excess moisture has been absorbed but before workability is lost. The grouting of any section of a wall shall be completed in one day with no interruptions greater than 1.5 hours.

72(10-0-0)

e. Inspection during grouting shall be provided in accordance with

73(9-0-1)

D-Ai1 Pi’iflTHI 1 V RL 1NF0RCH.D MA17MV

Partially 1

1

i nl m mil imnim i

' il m i n||| |i m mill i I masonry con- taining reinforcement as specified "i muni ini shall be and ties nay be embedded in the in n<« MTrTyvTntg nil 1 1 hl'i i m i I shall be embedded

in grout, “•’"inn"’ IITrrT and grout coverages i|i|i 1 n nh li in i'H 1 in thaLl—hw-pFovided. - -

-133-

A130
12A.3.7 Cont.

5A/38

cont.

5A/39

5A/40

73cont

.

" Partially reinforced masonry shall be designed as unreinforced masonry, excep_ thatsxe in forced masonry areas or elements may be considered as resisting stresses in accordance with the design criteria specified for reinforced masonry provided such ments fuTT>(s

comply with the design and construction requirements for reinforced mtfSonry

except as he^»in noted; however R factors of Table 3-B shall be as required Jpr jnreinforced masonry. Only T>Qgs M or S mortar shall be used

(A) REINF&RQEMENT. Reinforcing for columns shall confer to the requirement of Sec. 1 2A.6. 3(F). For wsjjs the maximum spacing of vertical reinforcement shall be 8 feet where the nominal thicknfess is 8 inches or greater and 6^<eet where the nominal thickness is less than 8 inches. VerKQal reinforcement shall^Tso be provided each side of each opening and at each comer of JiJ walls. Horizontal reinforcement not less than 0.2 square inch in area shall be provided afcsthe top of>F6otings, at the bottom and top of wall openings, near roof and floor levels, andst the^ttSp of parapet walls and, where distributed

joint reinforcement is not provided, at a ma'xtfljjrn spacing of 12 feet where the nominal masonry thickness is 8 inches or greater apo!3 ffeet where the nominal thickness is less than 8 inches. The vertical reinforcenjetu ratio anch<he horizontal reinforcement ratio

shall each be not less than 0.00027

Where not prohibi tpd'oy Chapter 12 or this Chapt&v. stacked bond construction

may be used. When stacked bdfid is used the minimum hori zontal reinforcement ratio shall be increased to 0.0007. Tb>? ratio shall be satisfied by masonry joirtsTeinforcement spaced

lot over 16 inches oM!y reinforcement embedded in grout spaced not ovfe^4 feet. Rein- forcement shall b^tfontinuous at wall corners and intersections.

SpJ*fces for reinforcement shall conform to all requirements for s'lXices in reinforced>rtSsonry.

Partially reinforced masonry walls shall be considered as reinforced masonrj

the purpose of applying Table 12A-2.

12A.3.8 GLASS MASONRY

74(6-0-4)I

75(6-0-4)

Masonry of glass blocks may be used in nonloadbearing exterior or interior

walls and in openings, either isolated or in continuous bands, provided the glass block panels have a minimum thickness of inches at the mortar joint.

3.0

The panels shall be supported laterally to resist the horizontal forces specified in Chapter 8. Glass block panels for exterior walls shall not exceed 144 square feet of unsupported wall surface nor 15 feet in any dimension. For interior walls, glass block panels shall not exceed 250 square feet of unsupported area nor 25 feet in any dimension. N p by proporation.

Glass block shall be laid in Type? H- wS mortarl Both vertical and horizontal mortar joints shall be at least 1/4 inch and not more than 3/8-inch thick and shall be completely filled.

Every exterior glass block panel shall be provided with 1 /2-inch expansion

joints at the sides and top. Expansion joints shall be entirely free of mortar, and shall

be filled with resilient material.

Sec. 12A.4 DETAILED REQUIREMENTS

76

( 10- 0-0 )

Masonry shall be designed to resist all vertical and horizontal load effects including effects of eccentricity of application of vertical loads. Unreinforced masonry

shall not be loaded in direct tension. Structural and nonstructural elements including

-134-

A131
12A.4 Cont.

5A/40

cont

.

5A/41

5A/42

I )

partitions shall be designed for seismic forces induced by their own weight. Design of structural masonry that is not part of the seismic system shall consider the effects of seismic drift in accordance with Sec. 3.8.

77(7-0-1)

Except where specifically allowed otherwise, stresses shall be calculated on actual net dimension of masonry considering reductions for raking, tooling, and other joint treatments and partial bed or head joints where applicable. Where required by the Regulatory Agency, Chapter 12, this Chapter, or by other governing provisions, ^pee i fi » inspections

and tests shall be provided. In addition where called for or where required by the use of design stresses so specifying. Special Inspection shall >be provided.

12A.4.1 COMBINATION OF DISSIMILAR UNITS OR CONSTRUCTION

In walls or other structural members composed of different kinds or graces of units, materials, mortars, or construction types, the maximum stress shall not exceed the allowable stress for the weakest of the combination of units, materials, mortars, or con- struction types of which the member is composed. Alternatively, provided the effects of different modulii of elasticity are accounted for in design, the maximum stress shall not exceed the allowable stress for the material occurring at the point of stress consideration. The net thickness of any facing unit which is used to resist stress shall not be less than 1.5 inches.

In cavity walls composed of different kinds or grades of units or mortars the maximum stress shall not exceed the allowable stresss for the weaker of the combination of units and mortars where both wythes are loadbearing; where only one wythe is loadbearing maximum stresses shall not exceed the allowable stresses for the units and mortars of that wythe.

1 2A.4.2 THICKNESS OF WALLS

78

( 10- 0- 0 )

79

( 10- 0-0 )

80

( 10- 0- 0 )

All masonry walls shall be designed so that allowable stresses are not exceeded

t their thicknesses are not less than required bv the maximum thick ness i iiiini nTT the minimuiTT~fTrfrkfl«i&£jof Table 12A-2. When a change in mini hi [, iwb 'i i rrrjTTTiimi m

occurs between floor lever* »hy nreater thickness gh;>rl hp rim i-mr^Fht-hp higher floor

level. In computing the thicknessrTn^~fo^d«i32^3TTsTthe value for thickness shall

oe determined by Footnote 5 ofTabl&-i5A*2T fn i7TTT*~i nmpn u i,l nf ili IT I kinds or classes

of units or mnrtarC- ^hp nit tfl**nThpi nhf tO length tO I ll il I III ITlll mil | Mill that allowed fgj I In gfgfestj i f the combination of units and mortars of which the and that the provisions of table 12A- 2 are satisfied.

EXCEPTION:

The maximum thickness ratio of Table 12A-2 may be increased and the

1 ZA .4.3

m nominal thicknessess of table I2A-2 may be decreaseo wne£, data iT'Sijfciaitted which justifies such liberalization and^^pfCval

is obtained fTSirr-theRegulatory Agency. For alllw£l45"Snd elements serving to support ve?t4«aJloads other th^fr-ivitfuced by the walls or elements themselves such data'>hajji»e+tl3e consideration of the additional eccentricity of vgjAiTrSTroad^ue to deflections perpen- dicular to the planeoi--tfiewall or e 1 emervT*amL^for unreinforced

*nd partiallvjerrtforced masonry, a consideration3T->st£ess and staiil it^jifldgFreduced vertical loads in accordance with the^wa^isions

prc \ar.n 1 i nr inn-inn Formula 3- 7a fnr unroi nfnrrprt when justified by substantiating data.

PIERS

Every otructw°»l pion-wheoe -witoh 4* tha n throe ti 4tS'

4

hioknets t h i ll bo des i gned a nd so n s try i t ed at required t a r sa l umn t,

-135-

A132
12A.4.3 Cont.

80cont

.

structural pier in reinforced masonry construction wnose wiTfn i r hrTTi?rff

3 and 5 times Tr ^

an i n the h eight of ml i nr r n l ii|il lnini lull have all horizontal steel in the form of ti esexca5SS*wt-"ftC555lJ s less tha n 12 inches in nominal thickness and in re jnfnrrnii n illlil -nn~trnrtirn such -t~T ii

i "" "t lfiyr- the

I III III i'l I I' ITi

12A.4.4 CHASES AND RECESSES

Chases and recesses in masonry walls shall be designed and constructed so as to satisfy the required strength or fire resistance of the wall. See Sec. 12A.2.8.

12A.4.5 HOLES. PIPES, AND CONDUITS

Pipes, conduits, and similar items may be sleeved through masonry with sleeves

large enough to pass hubs and couplings. Pipes, conduits, and similar items may be embedded

in masonry, provided all applicable provisions for Sec. 6.3 of ACI Standard 318 are satisfied. The design shall consider the net section at the location of the weakening element. Details

shall be shown on the approved plans. In applying ACI Standard 318, the terms "concrete"

and "structural concrete" shall mean masonry. (See Sec. 12A.2.8.) Unless all of the above requirements are satisfied, holes and embedments are not allowed.

5A/42

cont

.

12A.4.6 ARCHES AND LINTELS

Members supporting the vertical load of masonry shall be of noncombustible

materials.

12A.4.7 ANCHORAGE

Masonry walls that meet or intersect shall be bonded or anchored as required by Sec. 12A.2.1 and 12A.2.2 except where separation is provided for in the design. Masonry

walls shall be anchored to the roof and floors as required by Sec. 3.7.6. Structural

members framing into or supported on walls or columns shall be bonded or anchored thereto.

12A.4.8 END SUPPORT

81

( 10- 0 - 0 )

82

( 9 - 0- 1 )

column Beams, girders, or other similar concentrated loads supported by a wall or pion ^shall have a bearing at least 3 inches in length upon solid or grouted elements of masonry not less than 4 inches thick or upon a metal bearing plate of adequate design and dimensions. The loads shall be s*foly> distributed to the wall o ri&+cr, or to a continuous

reinforced masonry member p roooGtiwq ne t lo»t ttwn' S inoho s fnem 6*10 fasa nf..th» *ia n , or by other approved means.

Joists, precast planks, and similar elements shall have a bearing at least

2.5 inches in length upon solid or grouted masonry elements at lea st 2,36 i n sfeefc '. Shier , or other provisions shall be made to distribute the loads to the masonry.

Anchorage to the masonry shall conform to Chapter 3.

12A.4.9 DISTRIBUTION OF CONCENTRATED LOADS

In calculating wall stresses concentrated loads may be distributed over a maximum length of wall not exceeding the center-to-center distance between loads.

Where the concentrated loads are not distributed through a structural element

the length of wall considered shall not exceed the width of the bearing plus four times the wall thickness.

A133
12A.4.9 Cont.

5A/42

cont

.

83

( 10- 0-0 )

Goweewt in i to d l eads s ha ll ne t he se nt ) da red to he d i -t-w. i buiad b y me t a l tut in stacked bo nd co ns.t r uc ti o n, nor to be di stri tout ed icrrnt rnntiauaus vertica l jnintu—te

p eO e iC not p rohi-bitoh.

ihall apply when considering overtu rnin g effects in s hea r wa ll s if s tac k.ee bond

Concentrated loads shall not be considered to be distributed across continuous

vertical joints unless reinforced horizontal elements designed to distribute the

concentrated loads are employed.

Sec. 12A.5 STRENGTHS AND ALLOWABLE STRESSES

Material strength determinations and allowable stresses shall conform to the requirements of this Section.

12A.5.1 MASONRY

Except for the stresses listed in Table 12A-3 which are applicable to unreinforced masonry, the design of masonry is based on the compressive strength f^. The strength f,J, is reduced when the design is based on the alternate design procedure for unreinforced brick masonry of Sec. 12A.6.2. The higher stresses allowed in the Tables in this Chapter under the heading "Special Inspection Required" may only be used when all the applicable requirements for Special Inspection have been met; see Sec. 1.6 and 12A.7.

(A) DETERMINATION OF MASONRY COMPRESSIVE STRENGTH f^. When required for design, the value of f,{, shall be determined by tests of masonry assemblies in accordance

with 1 2A. 5.1 (A) . 1 or shall be assumed in accordance with 1 2A.5.1 (A) .2.

1. Determination of f^ by Prism Tests. When the masonry strength is to be established by tests, the procedures shall conform to the provisions of Sec. 12A.8 with

tests made both prior to and during construction.

2. Assumed Compressive Strength f^. When prism tests are not made as in 12A.5.1 ( A ) . 1 , fjj, may be assumed as listed in Table 12-4 provided other tests are made and certifications are furnished when required by the footnotes to Table 12-4 or by the provisions upon which the design is based.

The tests in 12A. 5.1(A).! and 2 shall not qualify the masonry for the stresses entitled "Special Inspection" unless Special InsDection fully conforming to

Sec. 1.6 and 12A.7 is provided.

83A - New

( 10-0-0 )

(B) ALLOWABLE STRESSES FOR MASONRY. Except for unreinforced biMe U masonry

designed under the provisions of Sec. 12A.6.2, the allowable stresses for unreinforced masonry are given in Table 12A-3 and for reinforced masonry the allowable stresses are given in Table 12A-5.

If used for design, the value of f^ shall be clearly shown on the plans.

12A.5.2 STEEL

Stresses in reinforcement shall not exceed the following;

TENSILE STRESS:

For deformed bars with a yield of 60,000 pounds per square inch or more and in sizes No. 11 and smaller

Joint reinforcement, 50 percent of the minimum specified

yield point for the particular kind and grade of steel used, but in no case to exceed

For all other reinforcement

POUNDS PER SQUARE INCH

24,000

30.000

20.000

-137-

I

I

!

I

1

I

G

8

I

I

I

A134
12A.5.2 Cont.

POUNDS PER SQUARE INCH COMPRESSIVE STRESS IN COLUMN VERTICALS:

40 percent of the minimum yield strength, but not to exceed 24,000

COMPRESSIVE STRESS IN FLEXURAL MEMEBERS:

For compressive reinforcement in flexural members, the allowable stress shall not be taken as greater than the allowable tensile stress shown above.

The modulus of elasticity of steel reinforcement may be taken as 29,000,000

to 30,000,000

12A.5.3 BOLTS

84(9-0-1)

5A/42

cont

.

85 - Mod

( 10- 0- 0 )

The allowable shear loads on bolts shall not exceed the values given in Table

12A-6. See Sec. 12A.2.7 for construction requirements.

Sec. 12A.6 DESIGN REQUIREMENTS

The design of masonry elements shall conform to the appropriate provisions of this Section. The higher stresses allowed in the Tables in this Chapter under the heading

“Special Inspection Required" may only be used when all of the requirements for Special

Inspection have been met; see Sec. 1.6 and 12A.7. The load combinations of Sec. 3.7 shall be investigated. All plans shall clearly show the specified value of fjf, used in design*

and tho ago whan the masanry-oJamants may be leaded. All stresses and capacities shall be based on actual net dimensions, thickness and sections.

12A.6.1 DESIGN PROCEDURE FOR UNREINFORCED MASONRY

The design of unreinforced masonry shall be based upon a rational analysis using

accepted engineering practice and linear stress and strain relationships. -A* £} ternate procedure* for designY*# given in Sec. 12A.6.2. are

(A) LIMITATIONS. The stresses on masonry elements including the stresses at

the extreme fibers of the masonry element resulting from the combined effects of flexural

and axial loads shall not exceed those given in Table 12A-3. The allowable compressive

stresses of Table 12A-3 are applicable only if the thickness ratios of Table 12A-2 are not exceeded.

The allowable stresses for compression of Table 12A-3 shall be reduced by 20 percent when applied to columns.

Each wythe of cavity walls shall be designed separately for the loadings

and effects imposed on it. The wythes shall not be assumed to act compositely.

(B) EFFECTIVE THICKNESS. For solid walls and metal tied walls, the effective thickness shall be determined as for cavity walls unless the collar joints in such walls

are filled with mortar or grout.

For cavity walls loaded on both wythes, each wythe shall be considered to act independently and the effective thickness of each wythe shall be taken as its actual thickness. For cavity walls loaded on one wythe only, the effective thickness shall be taken as the actual thickness of the loaded wythe.

-138-

A135
12A.6.KB) Cont.

For rectangular columns, the effective thickness shall be taken as its actual thickness in the direction considered. For nonrectangular columns, the effective thickness shall be taken as equal to 3.5 times its radius of gyration r about the axis considered.

Where raked or similar mortar joints are used, the thickness and length of

the member shall be reduced for stress considerations in accordance with the depth of the raking.

(C) ECCENTRICITY NORMAL TO AXES OF MEMBER. In solid walls and columns, the eccentricity of the load shall be considered with respect to the centroidal axis of the member.

In cavity walls loaded on one wythe, the eccentricity shall be considered

with respect to the centroidal axis of the loaded wythe. In cavity walls loaded on both wythes, the load shall be distributed to each wythe according to the eccentricity of the load about the centroidal axis of the wall.

For members composed of different kinds or grades of units or mortar, the variation in the moduli of elasticity shall be taken into account and the eccentricity

shall be considered with respect to the center of resistance or the centroidal axis of the transformed area of the member.

(D) EFFECTIVE HEIGHT. Where a wall is laterally supported top and bottom, its effective height shall be taken as the actual height of the wall. Where there is no lateral support at the top of the wall, its effective height shall be taken as twice the height

of the wall above the bottom lateral support.

Where a column is provided with lateral supports in the directions of both principal axes at both top and bottom, the effective height in any direction shall be taken

as the actual height. The actual height shall be taken as not less than the clear distance between the floor surface and the underside of the deeper beam framing into the column in each direction at the next higher floor level.

Where a column is provided with lateral support in the directions of both principal axes at the bottom and in the direction of one principal axis at the top, its effective height relative to the direction of the top support shall be taken as the neignt between supports and its effective height at right angles to this shall be taken as twice

its height above the lower support.

In the absence of lateral support at the top, the effective height of a column relative to both principal axes shall be taken as twice its height above the lower support.

(E) CROSS-SECTIONAL AREA. For solid walls and columns, A

g shall be taken as the actual gross cross-sectional area of the member. For metal-tied walls, A

g shall be determined as for cavity walls unless the collar joints in such walls are filled with mortar or grout.

For cavity walls loaded on one wythe, A

g shall be taken as the actual gross cross-sectional area of the loaded wythe.

In hollow unit construction, stresses shall be based on net areas.

-139-

A136
12A. 6.1(E) Cont.

5A/42

cont.

5A/43

Where raked or similar mortar joints are used, the thickness used in determining Ag or net areas shall be reduced accordingly.

<:;)(F) STIFFNESS. When used for design, the moduli of elasticity or rigidity

may be assumed from values that would be applicable to similar masonry construction

designed under other provisions of this Chapter. When the stiffness cannot or is not determined in this manner, supporting data shall be submitted.

86

( 10-0- 0 )

86A - New

( 10- 0-0 )

87 - Mod

( 8- 1 - 1 )

(G) SHEAR WALLS. Design of shear walls shall conform to the applicable provi- sions of Sec. 12A.6.4.inri Chapter 12.

(H) LOADS PERPENDICULAR TO CAVITY WALLS. The distribution to each

cavity wall wythe of loads perpendicular to the plane of the wall shall

consider relative wythe flexural rigidities, wythe end support conditions,

and continuity or lack of continuity of each wythe.

2A.6.2 ALTERNATE DESIGN PROCEDURE FOR UNREINFORCED BRICK MASONRY

For unreinforced brick masonry constructed with only new solid units made fpom

clay o\shale conforming to ASTM C62 or ASTM C216 and subject to the limitations of FjxJtnote

4 to Tab\e 12A-4, the alternate design procedure of this Section may be used. The requirements of Sec. 12A.6.1 apply except as specifically modified herein.

allowable stress compressive streni

value of the brick masonry design strength, fL., for establishing the for use in this Section shall be 0.73 of the value of th§

fch determined in accordance with Sec. 12A.5.1, i . e .

'masonry

mb 1.73 fl

All plans shafh. clearly show the values of f^, and at their required age.

(A) SLENDERNESS RATIOS. The slenderness ratio of a wall shall be taken as the ratio of its effective height, h\to the effective thickness% t, and shall not exceed the smaller of the values determined Table 12A-2 or as determined by the following

formula:

T = 10 (3 - T~) t e

2 (12A-1;

:

1 and e

2 are where the value of e,/e

2 is positive where tjj^isember is bent in single curvature, and negative where the member is bent in double^or reverse curvature. Where e both equal to zero, e^/ej shall be assumed to be zet^o.

The slenderness ratio of a column shabl be the greater value obtained by

dividing the effective height h inOny direction by the effective thickness t in the corresponding direction and shall/not exceed the value deteonined by the following formula:

5 (4 - (12A-2)

The minimum thickness and maximum slenderness requirements of Sec. 12A.4.2

shall also be satisfied. However, those requirements and the slenderness limits of the above formulas mav/oe waived in accordance with Sec. 1.5. Conformance to\the formulas,

by itself, shall/not act as a waiver for the requirements of Sec. 12A.4.2.\The require- ments of

ble, the ments of

stress aj loads,

the exceptions of that Section, as applicable, shall be satisfied, where applicaprocedures following this Subsection may be used in satisfyingshe requireexceptions. Particular attention shall be paid to the requirements for stability under reduced vertical load including Formula 3-2a and to transverse

(B) ALLOWABLE VERTICAL LOAD.

fresses shall be determined as follows:

The allowable vertical loads and bearing

- 140-

A137
1 2A .6.2(B) Cont.

5A/43

cont

.

1. Allowable Vertical Load. The allowable vertical load, P, on an

in forced masonry wall or column shall be determined in accordance with the followir

87 Hod. cont

.

a. When e/t or R

0

, as applicable, do not exceed 1/3:

P = fm

A C_ C

g

s e 12A-3)

where f is the allowable axial compressive stress f/6m Table

m

12A-7 •

A is the cross-sectional area of the elepi4nt determined

9 from the effective thickness and lenach.

C

$ is the slenderness coefficient asyfletermined by the following formula:

C

s = 1.20 - ^ [5.7 (1.5 /t1

) 2 ] 5 1.0 (12A-4)

\C is the eccentricity coefficient, related to the ratio of xe maximum effective eccenj/icity to effective thickness,

e/t as determined belt

Wh^o e/t is equal to or less than 1/20, the value of

When e/\ exceeds 1/20 but is equal to or less than 1/6 he/value of C shall be determined by use of

t^e following formula:

C "

= (f - ttt) 0 - i

1) 02A-5)

/+ 6 £ \

1 e

2

e/t exceeds l'te but is equal to or less than 1/3,

the value <H.Cp shall be determined by use of the following, formula:

1.95 (7 - f)

+ \ O - if) (12A-5a)

Pdf members subject to tranverse loadsygreater than 10 pounds per square foot between lateral supports, C e shall be based on F&(mula 12A-5 or 12A-5a, whichever is applicable^ except e^/ej shall be taken as 1.0.

When the elements are subject to bending aboHj both principal axes, the eccentricity coefficient is related to the ratio:

e it +e

t

i it ( 1 2A-6

)

where e

i is the effective eccentricity about the principal axis which is normal to the length of the element. '

is the effective eccentricity about the principal

axis which is normal to the thickness of the element.

141 1 of 7

A138
5A/43

cont

.

12A. 6.2(B) Cont.

87 Mod. cont

.

i is the effective length of the element,

t is the effective thickness of the element.

When R lX equal or less than 1/20 the value of C

0 is 1.0.

When Re exceeds 1/20 but is equal to or less than 1/6, the value of C

e shall be/netermi ned

by use of FormiH^ 12A-5 except that Rg shall be substituted for e/t. /

b. When e/t or Rg, as applicable, exceed 1/3:

For walls and elements subject to bendin^in one direction only

and the ratio e/t exceedKl/3, the maximum tensile and flexural concession stress

in the masonry, assuming irhear stress distribution, shall not exceed the values given in Table 12A-7. Where these van»^s are exceeded, the member shall^tfe redesigned and/or

reinforced.

For waV^s and elements subject to bending in both directions,

hall be redesigned and/or reinf

See Chapter 12 for nKvJi ficatioga under seismic loads.

and the ratio R

e exceeds 1/3, the mentors shall be redesigned and/or reinforced.

2. Bearing Stress. The bea>

and from similar concentrated loads supported,

values set forth in Table 12A-7.

stress under beams, lintels and girders unreinforced masonry shall not exceed the

(C) SHEAR WALLS. Design of/ihear walls Vt^al 1 comply with all applicable

provisions of Sec. 12A.6.4 and Chapter/12. In unreinfohced shear walls, the effective eccentricity ei about the principal Axis which is normal to the length i of the shear wall shall not exceed an amount which wjfl produce tension. In wire in forced shear walls subject

to bending about both principal axes, R

? shall not exceed l/3\ Where the effective eccentricity exceeds the values givjen in this Section, shear walls sH^ll be redesigned or reinforced.

Allowable vertical loads on unreinforced shear walls^^hall be determined

in accordance with Sec/12A.6.2(B) except that the value of h used in determining C

s may be taken as the minimum/vertical or horizontal distance between lateral supports.

fhe allowable shear stresses in unreinforced shear walls shaNbe taken as the allowable stresses given in Table 12A-7. The allowable shear stress may be\ncreased

by 1/5 of tharaverage compressive stress due to dead load at the level being analysed for

all loadings combinations except those including seismic loadings. In no case, howe^r,

shall thpiallowable shear stresses exceed the limiting values given in Table 12A-7.

(D) CONSTRUCTION. Masonry designed in accordance with this Section shall ha$

head" and bed joints with an average thickness not over 1/2 inch. All interior joints

iall be sol idly filled.

12A. 6.2

(Replace Sec. 12A.6.2 with the following:) ALTERNATE DESIGN PROCEDURES FOR UNREINFORCED MASONRY

Unreinforced brick masonry using solid clay units and unremfcrced concrete masonry may be designed by the alternate provisions

following. The requirements of Sec. 12A.6.1 shall apply except as specifically modified.

(A) UNREINFORCED BRICK MASONRY USING SOLID CLAY UNITS.

Unreinforced brick masonry using solid clay units may be designed under the applicable cited provisions of the "Building Code

Requirements for Engineered Brick Masonry", Brick Institute of America,

1969 (B1A-1969) subject to the design and construction limitations listed.

141 2 of 7

A139
4.7.12

1. Design shall conform to excluding Sec. 4.7.9, 4.7.10 and

2. Materials shall conform

B1A-1969 Sec. 4.7.1 through

4.7.12.5.

to B1A-1969 Sec. 2.2.1 and

2 . 2 . 2 . 1 .

3. Mortar joints shall conform to B1A-1969 Sec. 5.2

5A/43

cont

.

87 Mod.

cont

.

5A/44

Jr

9-0-1

4. Construction shall be solid masonry, cavity wall or grouted masonry - multiple wythe.

5. Allowable stresses shall conform to B1A—1969 .able 3 with the following modifications:

a. The words "without inspection" of B1A-1969 Table 3 shall mean "without special inspection". The words "with inspection

shall mean "with special inspection".

b. Allowable compressive and bearing stresses without

special inspection shall be 2/3 of those with special inspection.

c. Allowable flexural tension stresses without special

inspection shall be 1/2 of those with special inspection.

d. Allowable shear stresses without special inspection

shall be 60% of those with special inspection. _ 6. Modulii of Elasticity shall conform to Table 12A-5, this chapter

.

Brick ultimate this

7. ^.MasonryAcompressive strength f' for use ir.A-ehe alternate

procedure shall be 73% of the valuoc—obtai ned b y she a row i s

'

. -nf—Seir li A . a. a (A )—nf th] i. fliaptac which otherwise-are appln rar.la. taken from Table 12A-4, or shall be 82% of the

values obtained by prism testing according to section 12A.8 (h/t =2)

5A/45

8. References to 31A-1969 Sec. 4.7.9 and 4.7.10 shall rear, reinforced masonry conforming to the provisions for s me of this

chapter

.

9. Footnote 4 to Table 12A-4 is applicable.

10. The Slenderness requirements of Sec. 12A.4.2 this chapter

shall be satisfied; however these requirements and the slenderness limits

of the alternate procedure may be waived in accordance with Sec. 1.5 of Chap. 1. Particular care shall be paid to requirements for stress and stability under reduced vertical loads.

11. For walls and elements subject to bending in one directio

only, where the ratio e/t exceeds 1/3, the maximum tension and flexural compression stresses, assuming linear stress distribution, shall not be exceeded

.

12.

Design of shear walls shall comply with all applicable

provisions of this chapter. Loading combinations shall include reduced

vertical loads in combination with seismic loads, where applicaole. The allowable shear stress increase shall consider this vertical load reduction.

I

141 3 of 7

A140
r (B) UNREINFORCED CONCRETE MASONRY

.

5A/46

5A/47

87 Mod. cont

.

8- 1-1

Unreinforced concrete masonry using solid or hollow units and grouted or ungrouted construction, may be designed using the applicable

cited supplemental provisions of the "Specification for the Design and Construction of Load-Bearing Concrete Masonry", National Concrete Masonry

Assoc. , 1979 (NCMA - 1979) subject to the design and construction

limitations listed.

I ,3.3.2

1. Design shall conform to NCMA - 1979 Sec. 3.3.1„and

Sec. 3. 8. 6 through 3.8.8 except that allowable stresses and resistances

therein are for work only with special inspection; for work without

special inspection t he y shall b e ecd u eed 8 0% ** ' compressive stresses shall br reduced by 1/3, other stresses shall

be reduced bv 1/2.

_ . , , , 2 - Allowable shear and tension stresses shall conform to Table 12A-3, this chapter.

3. Mortar shall conform to NCMA-1979 Sec. 2. 2. 2. 2.

4. Joints shall conform to NCMA-1979 Sec. 4. 2. 3. 2.

5A/48

5. GEARING STRESS (f^)

On full area, ^ * - 25 i

' m

On coe-third area or less, • .30 f

’ m

87/7

( 9 -0

- 1 )

This increase shall be permitted only when the least

distance bet^en the edges of the loaded and unloaded

area is a mininun of 1/4 of the parallel side dbiEnsion

of the loaded area. The allowable bearing stress oc a reasonably concentric area greater than one-third, but

less than the full area shall be interpolated between

the values given.

141 4 of 7

A141
(O EESIGN, INREINKUCID HOLLO* CLAY MA33NKX

5A/49

87/1

(9-0-1)

C3*JNERAL

Ohreinforced masonry using hoi lew clay units may be used when

designed in accordance with the provisions of this section.

Hie allowable stresses shown herein are for work only with

special inspection, for work without special inspection these

allowable stresses shall be reduced by 1/3 for compressive stress,

other stresses shall be reduced by 1/2-

(Oi OOgRESSIOK IN WALLS AND COLONS

A. AXIAL IDADS

5A/50

Stresses due to compressive forces applied at the centroid of

the member may be ccnputed assuning uniform distribution over

the effective area. The allowable axial compressive stress is

given by:

F * .225 f’ [l-(h‘ /40t)

3

] waiis Eq. 12A-1

2L ID = 0.18 f^Q-(h/30t 3)J columns

in which:

87/4

(9-0-1)

5A/51

f

1 = ultimate compressive strength of masonry. m

Fbr assured values of f ' use Table 12A-1. m

h = (same as p. 14?)

t effective thickness (the m-in-imTM effective

thickness in the case of colums

ASSLMED VALUES OF f ' for use in Eq. 12A-1. m

The design ultimate ccnpressive stress of masonry,

f' m

> aY assured based ip»n the ccnpressive strength

of the units and mortar to be used. Values of f

m

which may be assuned are presented in Tables 12A-1.

141 5 of 7

A142
5A/51

cont

.

F, - .25 r Eq. 12A-2

br m

F

br .30 f ’m

Bq. 12A-3

87/6

(9-0-1)

87/8

(9-0-1)

87/10

(6-3-1)

B. BEARING STRESS (f^.)

On full area.

On one-third area or less, F

t This increase shall be permitted only when the least

distance between the edges of the loaded and unloaded

area is a minirmn of 1/4 of the parallel side dimension

of the loaded area. The alienable bearing stress on a

reasonably concentric area greater than one-third, but

less than the full area shall be interpolated between

the values given.

fto FFNmrr, HR (TWINED EENDING AND AXIAL IPADS

Stresses due to combined bending and centreidally applied axial

load shall satisfy the requirements of Section 12A.6.3(b) where

F

&

is given by Equation 12A-1 (A) and (B)

.

(03 FLEXURAL DESI(3J

A. Tensile stresses due to flexural shall not exceed the values

given in Section 12A.6.2. (c)^ where:

fh * Me/ 1 Eq. 12A.4

and:

f

fe * copyuted flexural stress due to bending loads only.

M = design ament on a section,

c = distance from neutral axis to extreme fiber.

I = moment of inertia of the section considered.

B. TENSILE STRESS - FLEXURAL (F

t

>

With no tensile reinforcement in masonry

Values for tension normal to head joints are for running

bond; no tension is allowed across joints in stack

bond masonry.

141 6 of 7

A143
87-10

cont

.

Tension Normal to Bed Joints (net bedded area)

Clay Dblts

24

5A/51

cont

.

87/12

(9-0-1)

5A/52 87/15

(no vote)

Hollow Obits, *

Tension Normal to Head Joints

Hollow Units, F = 48 psi

bedded

Stresses are calculated °n netwareas

Ccnpression stresses due to flexural (F, ) shall not exceed 0.33 f ' . D ll

(C)4. SHEAR IN FLEXURAL IffMTffTiS AND SHEAR WALLS

A. SHEAR IN FLEXUtAL MEMEEHS

m

= V/A Eq. 12A-5

where:

v = design shear stress with no shear reinforcement . The m

allcwable shear stresses, may be equal to

i.o>T7L but not to exceed 50 psi. m

= total design force

= effective area

Where vmas confuted by the foregoing equation exceeds the allowable

shear stress, V , web reinforcsnent shall be provided and designed to m

carry the total shear force in accordance with the requiranents of

A

reinforced masonry in Section 12.6.3. (c).

B. SHEAR WALLS WITH NO SHEAR REINFORCEMENT SHAJL BE DESIGNED USING

THE FOLLOWING EQUATIONS:

No shear reinforcement

a/L<l. V

m

= i- [4-f] £' m

. *>“*•

A/L>1, Vm

- 1.0 35 max. Eq. 12A-7

1A1 7 of 7

A144
it

87/15

5A/52 cont.

cont.

a = height of wall or segrent for cantilevered condition,

1/2 height of wall or segnent for fixed conditions

top and bottan.

L = length of wall or segnent.

The allowable shear stress in masonry may be increased by

0.2 f^j, where f^ is the caqpressive stress in masonry

due to dead load only.

C. SHEAR WALL OVERTURNING

87/13

(9-0-1)

5A/53

Not more than 2/3 of the dead load shall be used to resist overturning

due to horizontal forces. Any resultant tensile stresses shall be

resisted by reinforcing in accordance with the recyiirements of

Section. 12A.6*3.

(0 5. QQRBEIfi

87/14

(9-0-1)

5A/54

V

The slope of corbelling (angle measured fran the horizontal to the

face of the corbelled surface) shall not be less than 60°.

The maxinam horizontal projection of corbelling fran the plane of

the wall shall not exceed one-half the wythe thickness for cavity

walls or one-half the wall thickness for other walls.

12A.6.3 DESIGN PROCEDURE FOR REINFORCED MASONRY

The design of reinforced masonry shall comply with this Section and be based on accepted engineering practice for the "working stress" theory which incorporates the following principal assumptions:

• A section that is plane before bending remains plane after bending,

t Moduli of elasticity of the masonry and of the reinforcement remain constant.

-142-

A145
12A.6.3 Cont.

• Tensile forces are resisted only by the tensile reinforcement.

• Reinforcement is completely surrounded by and bonded to masonry material so that they will work together as a homogenous material within the range of working stresses.

Stresses shall not exceed those given in Sec. 12A.5 and this Section.

(A) FLEXURAL COMPUTATIONS. All members shall be designed to resist at all sections the maximum bending moment and shears produced by dead load, live load, and other forces as determined by the principles of continuity and relative rigidity. The clear distance between lateral supports of a beam shall not exceed 32 times the least width of the compressive flange or face.

In computing flexural stresses for masonry wall elements the effective

length tributary to a reinforcing bar shall be limited to: 88 1 . Running Bond. tne (10-0-0)

89(10-0-0) masonry units

2. Stacked Bond,

for construction using Three times the wall thickness or the stacked bond, whichever is less. length of the

(B) COMBINED AXIAL AND FLEXURAL STRESSES. Members subject to combined axial and flexural stresses shall be proportioned, except as modified by Chapter 12, so that

the following formula is satisfied:

90(7-1-2)

where

f = Computed axial unit stresses, determined from total axial load and effective area.

F

fl = Axial unit stress permitted by this Chapter if member

were carrying axial load only.

f

b

= Computed flexural unit stress.

F. = Flexural unit stress permitted by this Chapter if member were carrying bending load only.

Other interaction equations based on elastic

methods and design assumptions may be used.

(C) SHEAR AND DIAGONAL TENSION. The shearing unit stress, v, in reinforced masonry flexural members shall be computed by:

where:

b = The net effective width of a rectangular section or stem

of I- or T-sections. The value of bd shall not exceed

the net vertical shear area, net bedded area, nor the net cross-sectional area in hollow unit construction.

d = The effective depth.

-143-

A146
12A.6. 3(C) Cont. may be assumed as 0.85-t

5A/54

cont

.

91

( 10- 0-0 )

92

( 10- 0-0 )

93

( 10- 0- 0 )

94

( 10- 0- 0 )

j = Ratio of distance between centroid of compression and centriod of tension to depth, d. j = ^r&jpr j may be determined by a strain compatibility analysis.

the vertical joints

In vertical joints cf stacked bond construction, t he maoonryAShall not be assumed to resist shearing stresses. Where the shear reinforcement is parallel to the vertical joints, reinforcement equal to the required shear reinforcement shall be provided

perpendicular to the vertical joints at a spacing not to exceed 16 inches. B on d beam u n its

s h all bo used foi ho llow - mnit conotnu e tiow i

Where the values of the shearing unit stress computed by Formula 12A-8 exceeds the shearing unit stress, vm , masanmy wafe

J(remtorcement snail be provided to carry

the entire stress. Web fein Wo noomanfr -i h a il snots ttaekobAond jtiintt . shear shear

1. 44ob Reinforcement. Web' reinforcement shall consist of: Shear

a. Bt-i nnups - oe wofe reinforcement bars perpendicular to longitudinal

steel , or Shear

b. S ti neupG o r we b reinforcement bars archored around or beyond the longitudinal steel and making an angle of 30 degrees or more thereto, or

c. Longitudinal bars bent so that the axis of the inclined portion of the bar makes an angle of 15 degrees or more with the axis of the longitudinal portion of

the bar, or

95(9-0-1)

98

( 10- 0 - 0 )

100

( 10- 0- 0 )

d. Special arrangements of bars with adequate provisions to prevent

slip of bars or splitting of masonry by the reinforcement. shear

Sti rr ups oi 1 other• Bars to be considered effective as^-web reinforce96

( 10-0- 0 )

ment shall be anchored at both ends. Required Area.

2.U • JStiU I rr1 I u pg^A. The I nc UlareaCU ofI steel, J UGG I , A , required 1 I I TT1 J iI rrI I up s placed I UUUU perpendicular to the longitudinal reinforcement shall be computed by the following formula:

A = (12A-9)

v

Vs

97

( 10- 0- 0 )

99

( 10-0 -0 )

where V is the total shear, in pounds.

s is the spacing of st i rru p a -'W b e n t bars in a direction

parallel to that of the main reinforcement, inches. shear

:he allowable unit stress in thi psi,

bars

Inclined stirrups shall be proportioned in accordance with the provi- sions of paragraph 3 of this Subsection.

3. Bent Bars. Only the center 3/4 of the inclined portion of any longi- tudinal bar that is bent up for «eb reinforcement shall be considered effective for that purpose, and such bars shall beTbent around a pin having a diameter not less than six times the bar size. shear

-144-

shear

A147
12A.6. 3(C) Cont.

5A/54

cone

.

101

( 10-0-0 )

shear

When the -wete- reinforcement consists of a single bent bar or of a single group of parallel bars all bent at the same distance form the support, the required

area, Av , of such bars shall be computed by the following formula: \

" V Vin (12A-9a)

where a is the angle between inclined web bars and the axis of the beam.

Where there is a series of parallel bars or groups bent up at different distances from the support, the required area shall be determined by the following formula:

A =

v

Vs (12A-9b)

102

( 10-0 -0 )

103

(9-0-1)

105

( 10- 0-0 )

fvjd (sin a + cosa)

- shear shear

4. Spacing ofyrWefr Reinforcement. Where^we^ reinforcement is required it shall be so spaced that every 45 degree line extending from the mid-depth of the beam to the longitudinal tension bars shall be crossed by at least one line of»4*«U reinforcement.

> shear

(D) REINFORCEMENT DEVELOPMENT, ANCHORAGE, AND SPLICES. Reinforcement shall be arranged, placed, spliced, and anchored to develop design stresses therein and as specified

in this Subsection and Chapter 12.

1. General Development Requirements. The calculated tension or compression in the reinforcement at each section shall be developed on each side of that section

by embedment length or end anchorage or a combination thereof. For bars in tension, hooks

may be used in developing the bars. Plain bars in tension shall terminate in standard

hooks. Tension reinforcement may be anchored by bending it ac eeae t h e we b and making it continuous with the reinforcement on the opposite face of the member, or anchoring it the re

.

104

( 10 -0 - 0 )

The critical sections for development of reinforcement in flexural members are at points of maximum stress and at points within the span where adjacent rein- forcement terminates, or Reinforcement shall extend beyond the point at which it is no longer required to aociGt flexure for a minimum distance equal to the effective

depth of the member or 12 bar diameters, whichever is greater, except at supports of simple

spans and at the free end of cantilevers. Continuing reinforcement shall have an embedment

length not less than the development length 1^ beyond the point where bent or terminated

tension reinforcement is no longer required to resist flexure.

Flexural reinforcement shall not be terminated in a tension zone unless one of the following conditions is satisfied:

that permitted, or

a. Allowable shear stresses at the cutoff point do not exceed 2/3 of Area of shear reinforcement

b. a woaAi n excess of that required is provided along each terminated bar over a distan ce from the termination point eoual to 3/4 the effective depth of the member. The stWirup^shal 1 be proportioned to provide 50 percent of the allowable

shear capacity of the member based on the allowable shear stresses of Table 12A-5 for rein- forcement taking no shear. The resulting spacing s shall not exceed d/86b where 3^ is the ratio of the area of bars cut off to the total area of bars at the section, or snear reinforcement

- 145-

A148

I

I

I

I

I

J

I

R

R
1 2A. 6.3(D) Cont.

V

5A/55

i

5A/56

i

c. The continuing bars provide double the area required for flexure

at the cutoff point and shear stresses do not exceed 3/4 of that permitted.

2. Positive Moment Reinforcement. At least 1/3 of the positive moment reinforcement in simple members and 1/4 the positive moment reinforcement in continuous

members shall extend along the same face of the member into the support, and in beams at least 6 inches.

i When a flexural member is part of the primary lateral load resisting

system, the positive reinforcement required above to be extended into the support shall 106 be anchored for its tension development length, l d

, or if the support is not of masonry (6-4-0) construction, the reinforcement shall be anchored to develop its yiol d s tren g th at the face of the support. calculated stress

At simple supports and at points of inflection, positive moment

tension reinforcement shall be limited to a diameter such that the required development

length, 1 d , determined in this Section does not exceed:

M

V

c + ( 1 2 A— 10)

Where M

c is the lesser moment capacity of the member, based on allowable stresses, deter- mined from both the masonry and the reinforcement, and V is the maximum applied shear

at the section. At the point of support, l a shall be the sum of the embedment length

supplied beyond the center of the support and the equivalent embedment length of any furnished hook or mechanical anchorage. At the point of inflection 1= shall be limited

to the effective depth of the member or'12db, whichever is greater, where db is the diameter of the reinforcement.

3. Negative Moment Reinforcement. Tension reinforcement in a continuous,

restrained, or cantilever member, or in any member of the primary lateral force resisting

system, shall be anchored in or through the supporting member by embedment length, hooks,

or mechanical anchorage.

Negative moment reinforcement shall be developed into the span as required by Sec. 1 2A. 6.3 ( D )

1

.

At least 1/3 of the total reinforcement provided for negative moment

at the support shall have an embedment length beyond the point of inflection not less than the effective depth of the member, 1 2db , or 1/16 of the clear span, whichever is greater.

4. Special Members. Adequate end anchorage shall be provided for tension reinforcement in flexural members where reinforcement stress is not directly proportional

to moment; such as: sloped, stepped, or tapered members; brackets; deep beams; or members

in which the tension reinforcement is not parallel to the compression face.

107

( 8-0- 2 )

5. Development Lengths. The basic development length, l d> f0r deformed reinforcement shall be at least CIS do fy./Obut not less than 24 d h for reinforcement of 40,000 psi yield strength nor 36d d for reinforcement over 40,000 psi yield strength, nor

less than 12 inches for reinforcing bars and 6 inches for masonry joint reinforcement

where

0.0015d,f — db

= the diameter of the smaller bar spliced, inches. b s 4- = the specified bar yiel d stre ngth , psi.

£ calculated stress

s

-146-

A149
1 2A. 6.3(D) Cont.

>

5A/56

cont

.

107 cont

.

1

for deformed reinforcement but not less than 12 inches.

EXCEPTIONS:

1. For deformed main compression reinforcement in columns that

are not part of the seismic system, these values may be reduced to 18d(j for bars of 40,000 psi yield strength and and 27dfc for bars over 40,000 psi yield strength.

2. In flexural members that are not part of the primary lateral load resisting system the development lengths may be reduced where excess reinforcement is provided. For these cases, the previously determined development lengths may be multiplied

by the ratio of the area of reinforcement required by design

to that provided. *

6. Hooks. The term “hook" or "standard hook" as used herein shall mean:

a. A complete semicircular turn plus an extension of at least 4 bar diameters at the free end of the bar but not less than 2-1/2 inches, or

b. A 90-degree bend having a radius of not less than 4 bar diameters

plus an extension of 12 bar diameters, or

c. For stirrup anchorage only, a 135-degree turn with a radius on the axis of the bar of 3 diameters, plus ah extension of at least 6 bar diameters at the free end of the bar.

f = 1-hpsTyPn i i> 4>~af fhp mnrfar or grout , ,1 i II III li

, 9 ifimediately cnrrT i in i irrampnt but not more

Sm strength , psi

,

Development lengths for plain reinforcing shall be twice that required

EXCEPTIONS:

1. The hook for ties placed in the horizontal bed joints, where permitted, shall consist of a 90-degree bend plus an extension of 32 bar

diameters.

2. The hook for ties in the form of crossties as described in this Subsection may have a 90-degree

hook at one end provided the 90-degree hooks are alternated with the 135-degree hooks along the bar.

Inside diameter bends shall be as required for concrete reinforcement.

Hooks having a radius of bend of more than 6 bar diameters shall be considered merely as extensions to the bars. In general, hooks shall not be permitted in the tension portion of

any beam except at the ends of simple or cantilever beams or at the freely supported ends of continuous or restrained beams.

For tension bars, the hook at its start (point of tangency) may be considered as developing not more than 3/8 of the allowable tensile stress or the develop- ment length, lj, for reinforcement of 40,000 psi yield strength and not more than 5/16 of

the allowable tensile stress of the development length for reinforcement over 40,000 psi yield strength.

Hooks shall not be considered effective in adding to the compressive resistance of bars.

-147-

A150
1 2A .6.3(D) Cont.

5A/56

cont.

Any mechanical device capable of developing the strength of the bar without damage to the masonry may be used in lieu of a hook. Tests must be presented to show the adequacy of such devices.

7. Splices. Splices shall be made only at such point and in such manner

that the strength of the member will not be reduced. Splices shall be made by lapping the bars, by welding, or by mechanical connections. Lapped splices shall not be used for tension tie members. T °* 002i

b F

s _ Lengths of laps, in inches, for deformed reinforcement shall be at least but not less than 40dt, for reinforcement of 40,000 psi yield strength

nor less than 60 d

b for reinforcement over 40,000 psi yield strength, nor less than 12 inches 107^ for reinforcing bars and 9 inches for masonry joint reinforcement. Lap lengths for plain

(10-0-0) reinforcing shall be twice that required for deformed bars but not less than 12 inches. The terms \ w and ^ shall be as defined in Sec. 12A.6.3(D)5. F

s EXCEPTION:

For deformed main compression reinforcement in columns

that are not part of the seismic system, the lap length may be reduced to 30db for bars of 40,000 psi yield strength

and 45db for bars over 40,000 psi yield strength.

Welded or mechanical connections shall develop the yield strength of

the bar in tension.

EXCEPTION:

For compression bars in columns that are not part of the seismic system and are not subject to flexure the compressive strength need only be developed.

Shear Shear

8. Anchorage of Reinforcement. -wee reinforcement shall be placed

as close to the compression and tension surfaces of the member as cover requirements,

practicability, and the proximity of other steel will permit, and in any case the ends of single-leg, simple- or multiple-U stirrups shall be anchored by one of the following means:

a. A standard hook plus an effective embedment of 5/8 l b for rein- forcement of 40,000 psi yield strength or 11/16 1 ^ for reinforcement over 40,000 psi yield

strength. The effective embedment of a stirrup leg shall be taken as the distance between

the mid-depth of the member, d/2, and the start of the hook (point of tangency), or

b. Embedment above or below the mid-depth, d/2, of the compression

side of members that are not part of the seismic system for a full development length l d , or

108

( 10- 0- 0 )

c. Bending around the longitudinal reinforcement through at least 180 degrees. Hooking or bending stirrups around the longitudinal reinforcement shall be con- sidered effective anchorage only when the stirrups make an angle of at least 45 degrees with deformed longitudinal bars not less in diameter than the stirrup bars.

Between the anchored ends, each bend in the continuous portion of a transverse simple- or multiple U-stirrup shall enclose a longitudinal bar, not less in diameter than the stirrup bars. , shear

109

( 10 - 0- 0 )

Longitudinal bars bent to act as -we^ reinforcement shall, in a region of tension, be continuous with the longitudinal reinforcement and in a compression zone

shall be anchored, above or below the mid-depth, d/2, as specified for development length

in this Subsection.

- 148 -

A151
1 2A .6.3(D) Cont.

5A/56

cont

.

Pairs of U-stirrups or ties so placed as to form a closed unit shall

be considered properly spliced when the laps satisfy the requirements of this Subsection.

9. Flexural Compression Reinforcement. Required flexural compression

steel in members that are not part of the seismic system shall be anchored (enclosed) by ties or stirrups not less than 1/4 inch in diameter, spaced not further apart than 16 bar diameters or 48 tie diameters. Such ties or stirrups shall be used throughout the distance where compression steel is required.

Required flexural compression reinforcement in members that are part of the seismic system shall be anchored as required for column longitudinal reinforcement.

5A/57

5A/58

110

( 8- 0-2 )

111

( 8- 2 -0 )

(E) REINFORCED MASONRY WALLS. Beinfoneod masonry b earing wa ll thi Gk. n e*s«< oho 1

1

eew fo wn to See* 12A 1 4 1 2 cmd- to the noquiromonts of thi'S.-S ofesoction and Chapter 1 2 *

1. Stresses. The axial stress in reinforced masonry bearing walls shall not exceed the value determined by the following formula:

h 0. 225

f; o - <*>’] (i2A-i i

;

where:

5A/59

112 (9-0-1)

5A/60

113

(9-1-0)

fm

= Compressive unit axial stress in masonry wall.

f

1 = Masonry compressive strength as determined by Sec. 12A.5.1

.

The value of f' shall not exceed 6000 psi. m

t = Thickness of wall in inches.

JEffective height or width,

plear distance in inches, between supporting or stiffening elements (vertical or horizontal ). Effective height or length different from clear distance mav be jised if

_

justified.

71 Reinforcement. Reinforcement of walls and wall elements shal vided for aTT nrarho^s ^pri nther requirements of these Regulations^___£jLC*pt—WFThe more stringent requirements ofTiTrple; 12 and this Chapter^js^ap^^WraETeTthe minimum reinforcenent ratio in each direction shall be J^n02^a»t4«tflSII|um^of the ratios for each direction

shall not be less than nn?

, Ma»a<mrn-T;gTrv^rrpmerrr7pa7mTTTv-ci^ l not exceed 4 feet on center. n"1/ wbi ch is continuous in thewaT

in computi ng the minimum area of rei nforcement.

2. Reinforcement. Reinforcement of walls and wall elements shall be provided for all loadings as required by design. Where reinforcement ratios ar« less than: A. 0.0007 in any direction, B. 0.002 or the sum of the ratios in each direction then; permissible stresses for unreinforced masonry must be used.

If reinforcement ratios are equal to or greater than these ratios, the stresses

of table 12A-5 may be used.

5A/61

If th e woll ic s true tod of th an two . units in thi c kn e ss , the

urn are-a- "Of requino^nea-ftSoncemont sh a ll bo equally di v ided into tw o lavenci o weeot des igned as nota-wii ng- wa4-Tfr»—Whene reinforcement is a dded above the mi n

t

ww»-

n

whet og ui

114

( 8 -1 - 1 )

wants tush, additional rainfnrrpmpnf need nnf he sn-.ftiuirifth. J'lhen using the stresses in Table 12. 5A, iHon zontai reinforcement shall be provided at the top of footings,

at the top of wall openings, at roof and floor levels and at the top of parapet walls. If continuous, these special bars may be considered in satisfying the minimum horizonal rein- forcement ratios of Sec. 12.7. ,0

^There shall not be less than one No. 4 or two No. 3 bars on all sides of, and adjacent to, every opening which exceeds 24 inches in either direction, and such bars shall extend not less than the development length, but in no case less than 24 inches,

beyond the comers of the opening. The ba re required by this para g raph s hall bo in aadiuior

tfr the min imum reinforcement requ ired el sewhere. .

-149-

A152
1 2A . 6 . 3 ( E ) Cont.

3. Columns Constructed Within Walls. When the reinforcement in bearing

walls is designed, placed, and anchored in position as for columns, the allowable stresses

shall be as for columns. The length of the wall to be considered effective shall not exceed the center-to-center distance between concentrated loads nor shall it exceed the width of the bearing plus 4 times the wall thickness.

4. Shear Walls. Shear walls shall, additionally, comply with the provisions of Sec. 12A.6.4.

(F) REINFORCED MASONRY COLUWS. The least dimension of every reinforced masonry column shall be not less than 12 inches.

5A/62

EXCEPTION:

The minimum column dimension may be reduced to not less than

8 inches provided the design is based upon 1/2 the allowable

stresses for axial load. Bending stresses need not be so reduced.

The axial load on columns shall not exceed: 0.20 F

h

P = A

g (-&T+& f; + 0.65 p

g «4) [(1 - ^) 3 ] (12A-12)

where:

P = Maximum concentric column axial load.

A = The gross area of the columns with deductions for

9 rakes and similar joint treatments.

116

( 10-0- 0 )

5A/63

117

(9-0-1)

f

1 = Compresssive masonry strength as determined by m

Sec. 12A.5.1 . The value of f^ shall not exceed

6000 psi.

p

P = Ratio of the effective cross-sectional area of g

a vertical reinforcement to A

g

.

f = Allowable stress in reinforcement; see Sec. 12A.5.2.

t = Least thickness of column in inches.

h = Cl e a t* he ight i n i w ohoc . Effective height-Clear distance in inches

between supporting or stiffening elements.

Effective height different from clear

distance may be used if justified

1. Vertical Reinforcement. The ratio pg shall not be less than 0.5 118 percent nor more than 4 percent. The number of bars shall not be less than four, nor the CIO n~m s ^ 2e ^ ess than No * ^-lExcept as provided in Sec. 12A.2.4(D), the maximum bar size shall be u J No. 10. Splices shal 1 1 conform to Sec. 12A.6.3(D)7.

3

2. Ties. All longitudinal bars for columns shall be enclosed by lateral ties. Lateral support shall be provided to the longitudinal bars, as specified

below, by the corner of a complete tie having an included angle of not more than 135 degrees or by a hook at the end of a tie. The corner longitudinal bars shall have lateral support provided by a complete tie enclosing the longitudinal bars.

Lateral ties shall be placed not less than 1.5 inches and not more than 5 inches from the surface of the column, and may be against the vertical bars or placed in the rizontal bed joints where permitted by Sec. 12A.3.5(C).

-150-

A153
1 2A .6.3(F) Cont.

5A/63

5A/64

5A/65

The spacing shall not be greater than 16 bar diameters, 48 tie diameters, or the least coluirr dimension, but not more than 18 inches.

Ties shall be at least No. 2 in size for No. 7 or smaller longitudinal

bars and No. 3 in size for No. 8 or larger longitudinal bars except that when No. 11 bars are allowed under the exceptions to Sec. 12A.2.4(D) the minimum tie size shall be No. 4.

EXCEPTION:

Ties placed in horizontal bed joints, where permitted by Sec. 12A.3.5(C) may be smaller in size than required

above but not less than No. 2 in size, provided that the total cross-sectional area of such smaller ties crossing

a vertical plane is equal to the area of the larger ties

at their required spacing.

See Chapter.. 12 for additiona l requi reme n ts, where app l icab le. -

12A.6.4

3. Y

G routi n g»—All columns shall bo grouted oolid . All column or longitudinal reinforcing shall

MASONRY SHEAR WALLS be solidly embedded in grout.

124

( 10- 0-0 )

The design of masonry shear walls and wall elements for in-plane shears shall conform to this Section, Chapter 12 , and all applicable provisions of these Regulations.

See Chapter 12 for stacked bond construction limitations based on construction categories.

(E) BOUNDARY ELEMENTS. Boundary elements are members at the ends of shear walls whichvresist overturning effects,

help

Unit compressive stresses in the masonry at wall openings shall conform

to the requirements of this Chapter unless boundary elements conforming to the provisions

of Sec. 12.7.2 are provided.

Reinforcement required to resist wall shear shall be terminated with a standard hook whieh-eBel-eses-the-beHBdary-peiRfeFeiBg at the end of the

wa ' ,! e

5

t -° nS ' The hook may be turned up, down, or horizontal and shall be nr

b hofm

d 1 u

lT°r

)bar °!” 9fout. Wall reinforcement terminating in boundry columns

or beams shall be fully anchored into the boundary elements.

^I-ALLS-CTING '..'ALLS AND MASONRY COLUMNS.

(A) I nte rsecting Walls and Masonry- Columns. Where shear walls intersect

a wall or walls to form symmetrical T- or I-sections, the effective flange width shall not exceed 1/6 of the total wall height above the level being analyzed, and its overhanging width on either side of the shear wall shall not exceed six times the nominal thickness of

the intersected wall for unreinforced masonry nor eight times the nominal thickness of the intersected wall for reinforced masonry.

Where shear walls intersect a wall or walls to form L or C sections,

the effective overhanging flange width shall not exceed 1/16 of the total wall height above

the level being analyzed nor six times the nominal thickness of the intersected wall for unreinforced masonry nor eight times the nominal thickness of the intersected wall for reinforced masonry.

Limits on effective flange width may be waived when approved after a review of a written justification.

The vertical shear at the intersection of shear wall web and flange

shall be considered in design.

(B) VERTICAL TENSION AND COMPRESSION STRESSES. Except as provided for masonry designed under the alternate design procedure of Sec.y iaA. 6 .2 as modifi ed by Chapte r 1 2, vertical stresses in shear walls shall be determined from the combined effects of vertical loadSand from tho- overturning effects of - lateral loade?—

M

inimum verti ca l loada

--ohal1 b e »4dered .

Formul a 3-2 a- s ha ll be u sed fa r u nra inforsed ma s onry d e sign

12A. 6.2 (A) •

-151-

A154
5A/65

cont

,

125

( 8- 2- 0 )

126

(9-0-1)

5A/66

127

(9-1-0)

128

( 10-0-0 )

1 2A .6.4(B) Cont. Ancnor3£6

i Allowable tension stresses for unreinforced masonry shall not be exceeded.

ne i n fa noonan t 55565558^0 the foundation shall be provided to resistvtension in unreinforced walls. calculated

(C) HORIZONTAL ELEMENTS. Provisions shall be made for shear and flexural effects in horizontal elements of shear wall systems, such as beams that coupleJfjSws-. Per

i atroooes oholl not be exceeded;—Tcnsi4e

forc in g conforming tft See. 1 2A. 6.3 (C) ,

(D) WALL SHEAR. In computing the shear resistance of the wall, only the web

shall be considered. Por uw rei w^o weed maoon wy The depth of the web may be considered out

to out of flanges. minimum

Shear resistance of masonry shall be based on^net areas parallel to the shear. Both vertical and horizontal shear shall be considered. includin g tho not socdo e area, the net cnasi.iactional area af hoi Law uni.ti , and tha net- w«.rvi.sc3- thee r area. Where

only partial mortar coverage is provided, such, as. in. aollow ufoA. santtructian wnara only

the fata shells ia.itha bad, joints and partial head joint .sovaraga imsually specified,

only tho-aotMat " t pooifiod ' mo i» ljan coverage shall -fe e eews i feewefe e ffective . However, Continuous vertical and horizontal grout elements may be considered as part of the net areas.

For reinforced masonry, the shear stress shall be computed by Formula

12A-8. Horizontal shear reinforcing, when required, shall be provided with that portion

required to resist shear uniformly distributed and spaced out not more than 1/3 the wall depth or as required by Sec. 12.7, whichever is less.

Reinforcement req uired to rac i s t w a ll s hea r sh a ll bo t e rmina t ed with a sections.

fully'

e l emontc

12A.6.5 SCREEN WALLS 5A/67 Masonry units may be used in nonbearing decorative screen walls. Units may be laid up in panels with units on edge with the open pattern of the unit exposed in the completed wall. 129

(10-0-0)

The panels shall be capable of spanning between supports to resist horizontal

forces. Wind loads shall be based on gross projected area of the feloelii panel.

130

(10-0-0)

—~ fhr maximum size ot panels shall be 144 square feet witn tne mi

in pithnrTTTynr'+irin nf is foot Each panel shall be supported rm j1

1

i member of concrete, n 1 u|'l 1

i at thp t M |i m n| the panel shall be by means of confinement of the masonry**IIV~*'ia»lM' i

| 1.'. inrh into and between the flanges of

a steel channel. The ^narp i

|

M i mi M | thp niiii'l I thp wph of the channel shall

be at li i 1 1, , mull mill hill In void of mortar. The use ofeqiTrTaiTn^-auifim^ation in othau- u Lull 1 aLLlions or in masonry or concrete is acceptable.

131

(10-0-0)

(A) UNREINFORCED PANELS. Unreinforced panels are allowed only in Category A construction provided allowable stresses are not exceeded. Otherwise the panels shall be reinforced as provided in Sec. 12A.6.5(B).

-1 52-

A155

walls
12A.6.5 Cont.

(B) REINFORCED PANELS,

be reinforced per Sec. 12.4.1(D).

All panels in Categories 8, C, or D construction shall

132

(9-0-1)

133

(9-0-1)

134

(9-0-1)

Sec. 12A.7 SK-6W4C"I N0PECTI0N0i CPEEIAL INSPECTIONS. AND TESTS

S pea ifi a and S p«e i»l Inspections shall be provided and Tests shall be made in accordance with the requirements of this Section. The Regulatory Agency may for masonry

work which it determines to be minor in nature waive requirements for certifications,

Spee4*4^ Inspections, Tests, Spee4 al-I es peef i en, or some items of Special Inspection.

The Spec i a l -

I

nspecti on s an d Tet ' tf . of. 13A i / . 3 , whewo a pp li e ab l ei o h all b e p we *4dee-*o^

all pa nts o f roas on icy' oon s tnuoti oou -' Tte"Sp«oi a l Inspection ne q ui wewcnto of S oc i

l .ci addition te - S oo . 12A . 7 . 2 and

apply . only to tho des ignated s oi s mio syc-tew..

Spooifi s a n d S p oo i a l Inspection shall be done to an extent that the Inspector(s) or testing agency can certify to the requirements of Sec. 1.6.4. I n go w e w ad r

1 l a ng e j efe o or fo r mode r a t e size jnhs , this will req u ire contin uous, ob s e rv a tion during th e masonry *end, Nw«eve i* | inGpeot i may be done -pe r iod ic ' basis pnev idod t h ey sati s fy the «ee u ments of thi s Chap ter and p rov ided thi s pe riodic sehedoted-anepeotion i s performed as- ect- linod in the project des i gn document. a or tho app roved Qua lity As s urawoo B l. avu r frequency of

12A.7.1 GPCCino jLlNSPECTlONS AND TESTS

5A/67

135

(9-0-1)

For all masonry construction, Spee i fi

o

Inspection, Certifications, or Tests

shall be provided when required by one or more of the following:

• When required by provisions of Chapter 12 and this Chapter.

• When in the opinion of the Regulatory Agency work involves unusual hazards.

o Where required by the approved Quality Assurance Plan or design documents.

The tpooifio Inspections, Certifications, or Tests may consist of one or more of those listed in Sec. 1 2A. 7.2(A) and 1 2A. 7.2(B) , however in order to qualify as Special

Inspection all the applicable Certifications, Inspections, and Tests of Sec. 12A.7.2 shall

be provided.

12A.7.2 SPECIAL INSPECTION AND TESTS

All applicable Special Inspections and Tests designated in Sec. 1 2A. 7.2(A) and

1 2A. 7.2(B) shall be provided when stresses entitled "Special Inspection" are used for design, when required by the items listed in Sec. 12A.7.1, and when Special Inspection is otherwise

required.

(A) SPECIAL INSPECTION. Special Inspection shall be provided as follows:

• For the examination of materials and/or certifications of materials for compliance.

• For the observation of measurement and mixing of field-mixed mortar and grout including checks on consistency.

• For the determination of the moisture conditions of the masonry units at the time of laying.

• For periodic observation of the laying of masonry units with

special attention to joints including preparations prior to buttering, portions to be filled, shoving, etc.

-153-

A156
12A.7.2 Cont.

t For observation of the bonding of units in the walls between wythes and at corners and intersections.

• For the proper placement of reinforcement including splices,

clearances, and support.

5A/G7

cont

.

• For observation of the construction of chases, recesses,

and the placement of pipes, conduits, and other weakening

elements.

• For inspection of grout spaces inmediately prior to grouting

including the removal of mortar fins as required, removal of dirt and debris, and the conditions at the bottom of the grout

space. For high lift work this shall be done prior to the closing of cleanouts and shall also include the proper

sealing of cleanouts.

r Ur Lmc pi Spot QtiUrif or bupcrVlaiun UT pr cpor Qt I on j ut rspuir fc samples such as mortar, grout and prisms.

For the observation of grout placement with special attention

to procedures to obtain filling of required spaces, the avoidance of segregation, and proper consolidation and reconsol idation.

5A/68

(B) TESTS ANWSft CERTIFICATIONS, andfw* supplied as follows. Tests andjtax certifications shall be performed

5A/69

5A/70

137

(9-0-1)

138

( 8 - 2- 0 )

• Foe mo eto>*T- 9i»»tit'j and pmiomoi. j[one prism test series shall be made for each 5000 square feet of wall. Alte rn ati v ely a geri e fl

' D* both me rt ar-^ nd ' grout' tiOGS6-<h aiM^Mli)»wnado on the - wwt"' tl w>ee

joouti v o ' dayO ' - of tho- work a nd on each thi rd day t’he reahte

In addition^

fill i o to be when fi | Dta b lic h od by tocto oqual to or a re a tor than 2 6 00 po of three pniorr scried ohall bo ma flo durin g tho p

rog rocs of-the- When fm

to be established by tests there shall be an initial prism test series prior to the start of construction.

The requirements for numbers of test series apply separately

for each variation or type of masonry construction. ewoept for

the bo *o4-

numbe r for a buildin g.

For masonry units. When shipments of masonry units are not identified and accompanied by certification acceptable be the Bogul a tar it Agency, one series of tests for strength, absorption, saturation, moisture content, shrinkage, and modulus of rupture shall be made for each 5000 square feet of wall or equivalent. When the reference document or standard for the units has no acceptance or rejection limits for a test, the test need not be made. Seismic Performance Category D,-

Fer u nr ei et o re e o 0 " rmance " 1 caceguty u,—

wf0*1000 grouted masonry^ one series of core tests for shear bond shall be made for each 5000 square

feet of wall or equivalent.

Move to

Ch. 12

- 154 -

A157
12A.7.2 Cont.

5A/71

;) • For cement used for mortar and grout, certification acceptable

to tile Regulatory Agency shall accompany the cement when the required volume of cement exceeds 500 sacks.

• For reinforcement. One tensile and bend test shall be made for each 2-1/2 tons or fraction thereof of each size of reinforcing.

Testing is not required if the reinforcement is identified by heat number and is accompanied with a certified report of the mill analysis.

• For plant mix ("transit mix") grout a certificate conforming

to both Sections 14.1 and 14.2 of ASTM C-94 shall accompany the plant mix. Substitute "grout" for ‘’concrete" in ASTM C-94, The requirements for the testing of groat shall also apply.

• For other tests performance shall be as indicated in the Approved Quality Assurance Plan.

Where the nunber of tests or test series is not defined, one test or test series, as applicable, shall be made for each 5000 square feet of wall or equivalent.

12A.7.3 LOAD TESTS

When a load test is required the member or portion of the structure under consideration shall be subject to a superimposed load equal to twice the specified live

load plus 1/2 of the dead load. This load shall be left in position for a period of 24 hours before removal. If, during the test or upon removal of the load, the member or portion of the structure shows evidence of failure, such changes or modifications as are necessary to make the structure adequate for the rated capacity shall be made; or, where

lawful, a lower rating shall be established. A flexural member shall be considered to have passed the test if the maximum deflection "D" at the end of the 24-hour period neither exceeds

nor D = Wrt

and the beams and slabs show a recovery of at least 75 percent of the observed deflection within 24 hours after removal of the load where:

L = span of the member in feet

t = thickness or depth of the member in feet.

12A.7.4 REPORTING

Reporting and compliance procedures shall conform to Sec. 1.6.4.

Sec. 12A.8 TEST CRITERIA

Masonry prisms, mortar and grout samples, and masonry cores shall be prepared and tested in accordance with the procedures in this Section.

12A.8.1 MASONRY PRISMS

Requirements for prisms shall be those of ASTM E447, except as modified by this Section.

-155-

A158
12A.8.1 Cont.

Prisms shall be built of the same materials, under the same conditions, and, insofar as possible, with tne same bonding arrangements as for the structure including the lapping of units except that for prisms which are one masonry unit in length, the units may

be laid in stacked bond. The moisture content of the units at time of laying, consistency

of mortar, and workmanship shall be the same as will be used in the structure for each type of construction.

Prisms shall be not less than 12 inches high and shall have a height to minimum

thickness dimension ratio of not less than 2.0 nor more than 5.0. Ungrouted hollow masonry

unit prisms shall be not less than one masonry unit in length. Solid grouted prisms of hollow units shall have a minimum length of one complete cell with cross webs. Solid masonry unit prisms or solid filled prisms shall be not less than 4 inches in length. The thickness and type of construction of the specimen shall be representative of the masonry

element under consideration.

Cores for hollow unit masonry shall not be filled. All cores for solidly

grouted reinforced hollow unit masonry shall be filled with grout. For prisms representing

partially grouted hollow unit masonry both unfilled and completely filled samples shall be taken and the value of fm used for design shall be a weighted average of both as estab- lished by the design authority and approved by the Regulatory Agency. The strength of f^ of each sample shall be taken as the compressive strength of the specimens multiplied by the following correction factor:

Ratio of H/d 2.0 3.0 4.0 5.0 Correction Factor 1.00 1.20 1.30 1.37

where

5A/71

cont

.

H = height of specimen in Tnches

d = minimum dimension of specimen in inches Intermediate values may be interpolated.

447 (A) STORAGE OF TEST PRISMS. For storage of test prisms follow Method B of ASTM C477 except as modified herein. Test prisms made in the laboratory shall be stored

for seven days in air, at a temperature of 70 degrees plus or minus 5 degrees, in a relative humidity exceeding 90 percent; and then in air at a temperature of 70 degrees plus or minus

5 degrees, at a relative humidity of 30 percent to 50 percent until tested. and protected from freezing and excessive drying-.

Test prisms made in the field shall be stored undisturbed|for 48 to 96 hours in the field under the same conditions, insofar as possible, and adjacent to the work 139 they are to represent. They ma y . be .^oworod w ith weed dawe . ouch oovomiwq- (8-0-2) •shall nuf thada the tidat from, tha twt. After field storage, they shall be transported to the laboratory for continued curing as specified for laboratory constructed prisms, r ie la-

•euring ma y sontirw e 'Spec ifi ed fa r tho initial sovon d ayo .

Test prisms and cores cut from the work shall not be taken before the work

is seven days old. Prisms cut from the work shall be stored as required for prisms made in the field.

(B) SAMPLING, TEST SERIES, AND COMPRESSION TESTS. Not less than five specimens

shall be made for each initial preliminary test series required to establish f^. Not less than three specimens shall be made for each field test series required to confirm that the materials are as specified in the design.

Priemr eh al 1 be 'c a pped a nd teated-iw eompr c s siew .—The ota wd oH ago of 140 test opocimonc shall bo 2 8- da ys » but 7 - day

- tes ts ma y bo used' provided the- rel ation botwoa n (10-0-0) 7 day a nd 2 8-day s trength s of.. tho mas onry iG oGtaoli 6hed by adequ a te frosts d a t a nwtori i l s used.

-156-

A159
12A.8.1 Cont.

(C) DETERMINATION OF f^. The value of frfi shall be the average value of all specimens tested but shall not be more than 125 percent of the minimum value determined by tests, whichever is less.

When approved by the Regulatory Agency, tests may be analyzed statistically

considering the variability of test results.

140A-New 12A.8.2 FE5-TS -TOO GftWT AND MOflTAR GROUT TEST AND FIELD MORTAR TESTS

(8-2-0) field

s Tests for grout and^mortar shall conform to this Section.

5A/71

cont.

(A) GROUT SAMPLES FOR COMPRESSION TESTS. On a flat, nonabsorbent base form a space approximately 3 inches by 3 inches by 6 inches high, i.e., twice as high as it is wide, using masonry units having the same moisture conditions as those being laid. Line

the space with a permeable paper or porous separator so that water may pass through the liner into the masonry units. Thoroughly mix or agitate grout to obtain a fully

representative mix and place into molds in two layers, and puddle each layer with a 1-inch

by 2-inch puddling stick to eliminate air bubbles. Level off and immediately cover molds

and keep them damp until taken to the laboratory. After 48 hours set, have the laboratory

carefully remove the masonry unit mold and place the grout samples in the fog room until tested in the damp condition.

141-Mod

(7-3-0)

MORTAR SAMPLES FOR COMPRESSION TESTS. Unread mnrfar nn rhc macnnii, HIT

t/2-inch I ii

'

' hull I li ji I PI n i a masonry unit on top of the mortal- and iiTfow to stand

for two minutes. in»nn<TTaro~n ftar anri place ij~a--?gTncTrbv 4-inch cylinder in two layers, compressing the mortar into i lllili i H

1 friT* stick or fingers. Lightly

tap mold on opposite s ides, lew ! uffTand iranediateTvTmiM Ids and keep them damp until

taken to thr lifinritr— After 48-hours set, have the 1 In ~ I'mrim m I place them—w—UlU I uqroom until tested in the damp condition.

(&; FIELD MORTAR SAMPLES FOR COMPRESSION TESTS. Spread a » ir.cn layer of mortar on masonry units having the same moisture conditions as those being laid. Place a masonry unit on top of the mortar and press

to achieve a 3/8 inch mortar joint. After pressing let stand fcr 2 minutes if the mortar contains 5/8 parts of lime to cement by vol me or less; let stand 3 minutes if the mix containes more lime. Immediately

xsnove mortar and place in a 2 inch round by 4 inch high cylinder mold

(or a 2 inch cube mold) , compressing the mortar using a flat stick or fingers. Lightly tap mold and level off. Immediately cover mold on opposite sides and keep it damp until taken to the laboratory. After

48 hours, the laboratory shall remove the mortar specimen fror the meld

and place it in a fog room until tested in the damp condition.

(C) SLUMP TESTS FOR GROUT. Slump tests for grout shall conform to ASTM Cl 43. Substitute the word "grout" for "concrete" in ASTM C143.

141A-New

( 8-2 -0 )

5A/72

141B -New

(6-4-0)

(D) COMPRESSION TESTS . Excluding curing, storage, and test age requirements

,

compression testing procedures for^mortar cubes shall conform to Sec. 8.6.2, 8.6.3, ana 9 of ASTM Cl 09 . Procedures for^mortar cylinders and tor grout shall conform to iec. flb.i.i through A. 6. 3. 6, A. 6. 4, and A. 6. 5 of ASTM C780.

FB4 REQUIRED S TRENGTH S , Urv4.-e

-ce higher otrongths-we

raquuad by th e

:onttry i;UMi-Ja&i»«ntt , minimum required—otrona cr-s—oh a I 1 tee

20 Oh—

geou-t-i

1 8 00 poi—feefield mortar cylinders—-see2 0 00 po ; fee

field nortat eub e a) .

12A.8.3 CORE TESTS FOR SHEAR 80ND

field

field

5A/73

1

Core tests for shear bond between grout and masonry units used in unreinforced

and reinforced grouted masonry construction shall conform to the provisions of this Subsection.

(A) SAMPLES. Samples shall be cores drilled from the wall with axes perpen- dicular to the face of the wall and diameters approximately 2/3 the wall thickness. These

shall contain no reinforcing and shall be taken from locations selected by the design engineer who shall also specify the procedure for repair of the holes in the wall.

(B) NUMBER OF TESTS. A test series shall comprise one test between grout and masonry unit for each combination of different grout type and/or masonry unit type. One test series shall be made for each 5,000 square feet of wall or equivalent but not less than one series for any building.

-157-

A160
12A.8.3 Cont.

5A/73

cont.

.

\

142

(7-1-2)

(C) PROCEDURES. The wall shall be at least 14-days old before cores are taken. Cores shall be tested at appwmima t a l y 28 days of age. Storage shall be as required for prisms. a minimum of

The apparatus shall be of an approved design, similar to a guillotine,

designed to shear only one wythe of masonry units from the grout. The shear force and its reaction shall be capable of being applied as close to the bond lines between units and grout as is practicable, one on one side of the plane and the other on the opposite side. Uniform bedding for the shearing force and the reaction shall be provided, both symnetric

about a plane which contains the axis of the core. No forces external to the core and per- pendicular to the shear plane shall be applied.

Core samples shall not be soaked before testing. The apparatus shall be placed and loaded in a testing machine as required for prisms.

The unit shear strength shall be calculated and reported as the maximum

load divided by the shear area. Visual examination of all cores shall be made to ascertain

if the joints are filled. The report shall include the results of these examinations and

the condition of all cores cut on each project regardless of whether or not the core specimens failed during the cutting operation. «w143

(7-1-2)

jhe a e otnongth sh a ll ne t be l ess tha n 100 p s i. Where an unusual number of cores fail during the cutting operation, the design authority shall determine if the test program is extensive enough to satisfy the requirements of Sec. 12A.1.5.

n>i

fj

clove to

Ch. 12

-158-

A161
5A/73

cont

.

-159-

A162
TABLE 1 2A—

2

5A/74

5A/75

5A/76

5A/77

147 (7-1-2)

MAXIMUM HEIGHT 'TO THICKNESS RATIOS

\ NOMINAL MINIMUM THICKNESS (INCHES)

3

/ \ Other Structural Uses /

TYPE OF MASONRY

—' ~

Maximum on

Maiehweea ratio*

unsupported

height or

length to Thickness 1

Hal\

whose\nly

structural function \s

exterior \

enclosure, \

nonstructural \

walls, and partitions

Thickness

for the uppermost

35 6 foot /

\high portioy V wall /

Thickne^

increyfe for

eachyflS feet

or faction

tj&reof Jte low the /uppermost

35 6 foot high portion

of wall

STRUCTURAL MALLS: Unbumed Clay Masonry 10 16 Stone Masonry 14 16 / 16\ 4 Cavity Hall Masonry 20 s 3 / 12 7 \ 4 Hollow Unit Masonry 20 8 / 12’ \ 4 Solid Masonry 20 3 /

' 12 7,e \ 4 Grouted Masonry 20 2 ,,2 6 / 10 7 .« \. 4 Reinforced Grouted Masonry

Reinforced Hollow Unit

05 1 » 36

36

2

6 /

6 \

Masonry

NONSTRUCTURAL AND PARTITIONS

6 / 6

Unreinforced 36 s / 2 __ \

Reinforced 46 / 4 -- ” \

‘For cantilever walls, the actual height or length, as applicable

thickness ratio shall be doubled.

used to compute the actual

2 If the only structural function of the wall is the enclosure of a building's exterior, the /

maximum thickness ratio may be increased to 22 for groutea masonry and 36 for reinforced walls.

‘ Thu mu 'Jnim ieea 1 wequ iw eMW M i. Cu e, lih .i o > a 1 ple a > 0 qj ,,,..., . u The thickness of plaster coatings may be considered in satisfying thickness ratios and minimum

thickness requirements but shall not be used to take stresses.

5 In determining the thickness ratio for cavity walls, an effective thickness shall be used.

For cavity walls loaded on both wythes the effective thickness for thickness ratio determination only shall be determined from the following formula:

150A -New

(7-2-1)

•Sfi (Tn

where In a ll th k ehweea a» wa ll i -* T = Vtf +

ua> » f

151

( 8-0- 2 ) 152

( 8 -0- 2 ) l

153

( 8-0- 2 ) 154

(7-1-2)

i =

C 1 =

C 2 h =

For cavity walls loaded on one wythe only, the effective thickness shall be taken for that loaded wythe only.

See Sec. 12A.6.KB) for the definition of effective thickness to be used for masonry design. See Sec. 12A.6.1 (e) for applicable cross-sectional areas for masonry design.

4 Gewe«<r feet

7Thee j be r e duc ed to 8 ine hea far heigh t in b u i I dingt *re3 Thee a thi c k net ft a

wall i i w aw a t awy aw il d i wga when th»

|-T -a x Vnr grn, .tan n ii i inn ft inrna t feu:. B f ee l in tot a l n e i ijnu,.. al-d maw nnM '«a<

whew gable i ex trut ti aw. i t Mtad- haignt u pimnrrertfr,f p^^i^iij, fhw imumnm rhirknass ranns fnr nfi ea fThru

<11 1)111 at «aep ie—a may m iwemtt ed tn 16

- 160-

A163
TABLE 1 2 A3

ALLOWABLE WORKING STRESSES IN UNREINFORCED MASONRY

5A/77

cont.

MORTAR TYPE

H —frnn n

Shear or Shear or Tension in Tensioni in Tension in MATERIAL 6 Compression 1 Compress ion 1 Flexure 2 ’ 3 » 9 Flexure, 3 , 4,8 Compression 1 Flexure*- 3 - 5

Special Inspection required NO No Yes No Yes NO NO Yes No

Solid Brick Masonry

>4501 psi 7 250 225 20 10 40 20 200 15 7.5 2501-4 500 psi 7 175 160 20 10 40 20 140 15 7.5 1500-2500 psi 125 115 20 10 40 20 100 15 7.5

Solid Concrete

Masonry

Grade N 175 160 12 6 24 12 140 12 6 Grade S 125 115 12 6 24 12 100 12 6

Grouted Masonry Multiwythe with Solid Units

>4501 psi 7 350 275 25 12.5 50 25 2501-4500 psi 7 275 215 25 12.5 50 25 1500-2500 psi 225 175 25 12.5 50 25

Hollow Uni

t

Masonry 5 170 150 12 6 24 12 140 10 5

Cavity Wall Masonry

k

Solid Units 5 >2501 psi 140 130 12 6 30 15 110 10 5 1500-2500 psi Hoi low Units100 90 12 6 30 15 30 10 5 70 60 12 6 30 15 SO 10 5

Stone Masonry

Cast Stone 400 360 a 4 — — 320 3 4 Natural Stone 140 120 8 4 — 100 8 4

Unbumed Clay Masonry 30 30 8 4 -- .

Allowable axial or flexural compressive stresses in psi gross on cross-sectional area (except as noted). The allowable working stresses in bearing directly under concentrated loads may be SO percent greater than these values. Allowable axial stresses are only applicable if the maximum

thickness ratios of Table 12A-2 are not exceeded. Reduce these values by 20 percent >Wien designing columns.

2 This value of tension is based on tension across a bed joint, i.e., vertically in the normal masonry work.

3 No tension allowed in stacked bond across head joints. “The values shown here are for tension in masonry in the direction of the bond, i.e., horizontally

between supports.

5Net bedded area or net cross-sectional area, whichever is more critical. Strengths listed in this column are those of masonry units.

7When the required strengths of the units exceed 2500 psi, compression tests of the units conforming to the applicable reference documents and Sec. 12A.7 shall be made. This shall not be required if certifications acceptable to the Regulatory Agency accompany the units. Allowable shear and tension stresses where lightweight concrete units are used are limited to 85 percent of the tabulated values.

- 161 -

A164
5A/ 7 7 cont.

87/2

( 9 - 0

- 1 )

TABLE 12A-4

ASSUMED COMPRESSIVE STRENGTH OF MASONRY

fm' PS'

TYPE OF UNIT

COMPRESSIVE

STRENGTH OF UNITS, psi OR GRADE

Solid Clay 4 and

Net Area of

Hollow Clay

14.000 psi 12.000 psi 10.000 psi 8.000 psi 6.000 psi 4.000 psi 2.000 psi Solid Unit s e thew 6,000 psi w»a« i

'.ay and Net Area4,ooo psi of Hollow Concrete PS1

1 ,600 ps

l

Concrete

gross 1 gross 1 gross 1 gross ! gross 1 gross 1 gross 1

gross4*’ gross'

gross'

gross

TYPE N MORTAR

4300 2,s 3800 :,s 3300 2 > 5 2700 2 • - 2200 s 1600 1100

1350

1250

1100

875

TYPE S MORTAR

5300 2

• 5 4600 4 • - 4000 2 » s 3300- • - 2600-

1900

1200

TYPE M MORTAR

6300-

5 5500-

5 4600- > - 3800- »

3000-

5 2200 5 1300 t»©2 4 0 0 2400 000 2000 HW155O'550

WMH5CH50

Concrete Gu . (i " 13b0 ~"TT55

3

Hoi low Co?te<ete - Grouted Solio''*^ Gd. N — 1500

Hoi low Clay Gd . LB wi th Min face Sh&VL

1350 1350

Hollow Clay - Grouted SolidGd. LB w^XT

1-V^Mfn face^"\- 5M^Tl - 1500 1500

Hollow Clay Brick 5,000 psi net 1 2500 s 2500 s

Hollow Clay^ffrick - GrouteO-'tfr RfPflforced Type I .. 2000

s When the required strength of the units exceeds 3000 psi, compression tests of ti.e units conforming to the applicable reference documents and Sec. 12A.7 shall be made. These tests shall not be required if certifications conforming to Sec. 12A.7 and Sec. 12A.8 and acceptable to the Regulatory Agency are provided during construction.

2 When the assumed f^ exceeds 2600 psi, prism tests conforming to Sec. 12A.7 and Sec. 12A.S shall be provided during construction. Certification of the units is not acceptable in lieu of tests. intermediate values may be interpolated.

'•When the alternate design procedure for unreinforced brick masonry of Sec. 12A.6.2 is used for design the units shall comply with the dimension and distortion tolerances specified for type FBS. 'Where such brick do not comply with these requirements, the compressive strength of brick masonry shall be determined by prism tests as required

by Sec. 12A.5.1 (A)l

.

sWhere grouted construction is used, the value of f^ shall not exceed the compressive

strength of the grout unless prism tests conforming to Sec. 12A.7 and 12A.8 are pro- vided during construction. As an alternative, the grout strength may be specified

at not less than the value of fm with grout tests conforming to Sec. 12A.7 and 12A.8 provided during construction for verification.

-162-

A165
TABLE 12A-5

ALLOWABLE WORKING STRESSES (PSI) FOR REINFORCED MASONRY

REINFORCED GROUTED

5A/78

5A/79

AND HOLLOW UNIT MASONRY

SPECIAL INSPECTION REQUIRED

TYPE OF STRESS YES NO 155A-New ' (6-4-0)

^Compression-Axial

,

Walls

See Section 1 2A . 6 . 3 (

E

) 2/3 , permitted under Section

1 2A .6.3(E) 155B -New

(6-4-0)

Compression-Axial

,

Columns

See Section 1 2A . 6 .

3

( F 2/3

) wi i of the values permitted under Section

1 2A .6.3(E) 156- Mod

(8-1-1) , Compress lon-Flexural 0.33 f^ but not to exceed’ *ee- 2000

0.166 f^ but not to exceed 1000

Shear:

Reinforcement

taking no shear 2 FlexuralShear wal Is 3 *** M/VD > l 6

1.1 ,71 50 Max.

.9 /F 40 Max. m

25

20 157 M/Vd = 0

6 2.0 , 7^

50 Max. 25 (void) Reinforcing

taking all shear

Flexural Shear walls 4 M/Vd 3 l 6

3.0 150 flax.

1.5 vTJ 75 Max.

75

35

M/Vd = 0

6 2.0 ,% 120 Max. 60

Modulus of Elasticity

600 Put not to exceed 3,000,000

500 ffj, but not to exceed 1,500,000

Modulus of Rigidity

240 fm but not to exceed 1,200,000

200 f' but not to exceed 600,000

158- Mod

Bearing on full Area 5 0.25 f,;, but not to exceed 300 1500

0.125 fm but not to exceed *00 750

(9-0-1) Bearing on 1/3 or

less of area 5 0.30 f,!, but not to exceed +S«»-1800

0.15 f^ but not to exceed wwfr 9QO

159 “1 (10-0-0)j

'Stresses for hollow unit masonry are based on net section.

r?l • shall be provided to carry the entire shear in excess of 20 pounds

psi whenever there is required negative reinforcement for a distance of 1/16 the clear

. span beyond the point of inflection. Allowable shear resisted by the masonry where lightweight concrete units are used is limited to B5 percent of the tabulated values.

11 Interpol ate by straight line for M/Vd values between 0 and 1.

5This i ncrease shall be permitted only where the least distance between the eages of

the loaded and unloaded areas is a minimum of of the parallel side dimension of the loaded area. The allowable bearing stress on a reasonable concentric area greater

than 1/3, but less than the full area, shall be interpolated between the values given.

is the maximum bending moment occurring simultaneously with the shear load V at the section under consideration.

-163-

A166
TABLE 12A-6

ALLOWABLE SHEAR ON BOLTS 1 »4

UNBURNED CLAY UNITS ALL OTHER MASONRY

DI/VCTER MINIMUM MINIMUM

SHEAR

SOLID "SWJUTED

OF BOLTS EMBEDMENT SHEAR EMBEDMENT MASONRY CONSTRUCTION

(Inches

)

(Inches) (Pounds) 2 (Inches

)

(Pounds) 2 (Founds) 2

1/4 -- - 4 — 180

3/8 — — 4 — 270

1/2 — - 4 230 370

5/8 12 130 4 330 500

3/4 15 200 5 500 730

7/8 18 270 6 670 1000

1 21 330 7 830 1 230 3

1-1/8 24 400 8 1000 1500 3

5A/80

160

( 8-1 - 1 )

5A/81

161

( 8- 0- 2 )

a Edge distance shall be not less than 2 inches nor 5 bolt diameters for edges

parallel to the direction of stress. Edge distances shall be not less than

3 inches nor 6 bolt diameters for edges perpendicular to the direction of stress. Center to center spacings shall be not less than 12 bolt diameters.

2 The tabulated values are for construction where Special Inspection is not provided. Where Special Inspection is provided 150 percent of these values .are permitted. -.net area

3 These values are permitted only with units having a minimumjfompressive

strength of 2500 pounds per square inch or more.

4An anchor bolt is a bolt that has a right angle extension of at least

3 diameters. A standard machine bolt is acceptable.

-164-

A167
162 - New

(9-0-1)

TABLE 12A-7

ALLOWABLE STRESSES TO BE USED WITH THE ALTERNATE DESIGN PROCEDURE FOR UNREINFORCED BRICK MASONRY 1

CooRjressive. «ial 2 Walls

Columns

Compressive, Flexural

Walls

Columns

Tensile. Flexural s - 6 Normal to bed joints 2 M or S mortar

N mortar

Paral lei to bed joints 3 M or S mortor

ALLOWABLE STRESSES, PSI without Special with spec/al INSPECTION INSPECTION

0.13 0.17 ^rnt>

0.10 f mb /l6

0.21 f

rrt> / 0.32 ^mb

0.17 fmb / 0.26 ^mb

Shear 7 M or S mortar But not eed 35

0.3» f ' Out not to exceeco

but not to 28 0.3'f,^ but not to exceed 56

Bearing

On full area

On one-third area or

less"

Modulus of Elasticity

Modulus of Rigidity

0.17 f

mb

°- 21 fmb

500 f^o but not tfc exceed 1,500, MO

psi

200 f' b but not to exceeo°600,000 psi

0.25 fL,

0.375 mb

600 f^D but not to exceeo 3,000,000

psi

240 f^b but not to exceeo 1,200,000 psi

JSee Section I 2A . 6/

2 Direction of stras is normal to bed joints; vertically in normal construction. direction of sRress is parallel to bed joints; horizontally in normal masonry construction. If rasrfnry is laid in stacked bond, tensile stresses in the horizontal direction

shall not bar permitted in the masonry.

“This increase shall be permitted only wnen the least distance between the ed^es of the loaded and unloaded areas is a minimum of one-fourtn of the parallel side dimension of the loaded area. The allowable bearing stress on a reasonably concentric area\reater

than o^e-third but less than the full area shall be interpolated between the vaia given

5 For/tomputing the flexural resistance of cavity walls, the lateral load shall oe di/xributed to the wythes according to their respective flexural rigidities.

the use of these allowable stresses, consideration shall be given to the influence'

6f unusual vibration and impact forces.

’’See Section 1 2A . 6 . 3 (c )

.

-165-

A168
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vr\ in sn in in\ JO 1 JO

A173
Chapter

12A

Page

A174

I

I
Cluster

1

2A

Page

A175
Chapter

12A

COV

30*X

A176
A177
CHAPTER i:

'iASONRv

3AC.<GRCU.N0 provide seismic

5/1 12-1/M-1

( 10 - 0 - 0 )

"he masonry ces ; gn ana construction orocsa-res ^iven i n crt s Cnao ter arc Dnapcer j ~ r- - ' ~ r- - -

9

in* H ' n

*0 r the seismic forces exclusively for the purpose of

this document.

12.1 REFERENCE OCCLMS.’ITS

sna, i oe as

'He quality and testing of masonry ana steel mater’als ana the design arc construe

tion of masonry ana '•einforoea masonry tomoonents .»nio.n '•es'st seismic ’orcas s r.a" ::"'o

r

to the reoui remen ts of Chapter 12A ar.c the 'eferences listed tne-'e

- '' except as mcc---ec o

y

trie provisions of this Chapter. For definitions, see Sec. 12A.1.1.

12.2 STRENGTH DF -'EMBERS AND CONNECTIONS

'he strength of memoers and connections suDjected to seismic "orces acting alcne : in comoination with otner orescrioed loads snail be determined -sing a capacity -ecucfcn

factor, o, ana 2.5 times tne allowaole wort<ing__i^rgiigs jf Chapter 12A, 'he /a „e of :

•‘o 1 1 ows : /or as tnese allowables are further modified by^

\this chapter

When considering axial or -lexural compression ana oear*ng

stresses in tne masonry. : 3 ' S

For reinforcement stresses except wnen considering s.near. ; - C.5

when considering snear carried by snear reinforcement anc oolts. : * C.5

when considering masonry tens’on caral'el to tne oec joints,

i.e., noricontally in noma; construction. o = C.5

when considering snear car-'aa by the masonry. : = S

.

When considering masonry tens'on perpendicular to tne oec joints, i.e., vertically in noma! construction. : 1 Zero

Stresses entitled "special inspection" in Chapter I2A shall

only be used wnen the work is fully inspected oer Sec. 1.5.2, 1.6.4 anc 12A.7. If fjJ, is to be established by test, a minimum of three orism

test series (as defined in 1 2A .3.1(3)) shall be made during the progress

of the work.

12.2.1 SPECIAL DESIGN PROCEDURES FDR j.NhlIN.'D'.CEj HASCNRY SUBJECTED "0 SEI 5” ID -DRCE5

.

j wwe i n fane q a llfcsonry snail be designed in accoroance with t.nis Section. UNREINFORCED

(A) Dari £ DAL DESIGN PROCEDURE. :Jnrei nforcea masonry cesignec in aooorcarce

with Sec. 12A.5.1 snail oe assumed to oe cracxeo in the tension zone, 'he 'es-ltant

linear distribution of compressive stresses must oe

- n eauiliprium wi tn tne aool'ec -‘c'tes ana the maximum comoressive stress must not exceed the val-es of 'ao'e 1ZA-3.

EXCEPTION

Sea joints of unrei iri'cac vertical comoor.encs constructed -si-c stacvec

bond, whic.n are suojactea to bending in cne oiane of tne pomponem , sna'

remain uncracxed.

12-1

A178
m

5/3

cont

.

12-3N

M-4

(9-1-0

M-5

(9-0-131

(3) REINFORCED MASONRY DESIGN. Reinforced masonry shall

be designed and constructed in accordance with one of the following

procedures and the provisions of other Sections of this Chapter.

1. Masonry designed and reinforced as required.

2. Masonry designed and reinforced as required

and containing nominal prescribed reinforcing. Construction shall

be grouted masonry — multi wythe or hollow unit masonry containing

reinforcement as specified below. Masonry joint reinforcement

shall be, and ties may be, embedded in the mortar in the bed

joints. All other rei nforcement shall be embedded in grout.

Minimum masonry, mortar, and grout coverages applicable to reinforced masonry shall be provided. Only type M or S mortar shall be used . Unreinforced masonry design procedures shall be used except that reinforced

masonry areas or elements may be considered as resisting stresses in

accordance with design criteria for reinforced masonry. The width of these

elements, tributary to the reinforcement, must meet the requirement of

effective width of masonry given in Section 12A.6. 3(A). Permissible shear stresses shall be determined in accordance with Section 12A.6.3(E). Per- missible axial loads shall be determined in accordance with 12A.6.1. The

R factor of Table 3-B shall be as required for unreinforced masonry unless

all masonrv structural elements are reinforced in accordance with Section

12. 2. 1(B) 3

.

Reinforcing for columns snail conform to the

requirement of Sec. 12A. 6.3(F). For walls the maximum spacing of

vertical reinforcement shall be 3 feet wnere the nominal thickness

is 3 inches or greater and 5 feet where the nominal thickness is less than 3 inches. Vertical reinforcement shall also be provided

each side of each opening and at each corner of all walls, horizontal reinforcement not less than 0.2 square inch in area shall be

provided at the top of footings, at the bottom and top of wall

openings, near roof and floor levels, and at the top of parapet

walls and, wnere distributed joint reinforcement is not provided,

at a maximum spacing of 12 feet where the nominal masonry thickness

is 3 inches or greater and 9 feet where the nominal thickness is less than 8 inches. The vertical reinforcement ratio and the

horizontal reinforcement ratio shall each be not less than 0.3002X.

Where not prohibited by Chapter 1 2A or this Chapter, stacked bond

construction may be used. When stacked bond is used the minimum

12-2

A179
5/3 cone

5/i

M-5

cont

.

12-4N

( 10- 0- 0 )

5/5

5/6

12-4-1

( 10- 0-0 )

12-4-2/M-6

( 10- 0- 0 )

horizontal reinforcement ratio shall be increased to 0.0007. This

ratio shall be satisfied by masonry joint reinforcement spaced not over 16 inches or by rei nforcement embedded in grout spaced not over

4 *eet. Reinforcement shall be continuous at wall corner's ana intersections

.

Splices for reinforcement shall conform to all requirements for splices in reinforced masonry.

These types of masonry walls shall be considered

12 49

l

n(G?

rCSd masonry for the ? urP°se of applying Table 12A-2. and section

3. Masonry designed and reinforced with prescrioea

. . .-in addition to the requirements of 12.2.1(B)(2). minimum areas? This additional reinforcement shall be in both

horizontal and vertical directions. The sum of the areas of reinforcement in both directions shall be at least equal to 0.002 times

the gross cross-section of the masonry with at least 0.0007 times

the gross cross-sectional area of the masonry in each direction.

12.2 SEISMIC ?ERrOR.“ANCE CA~EGCR V A

3uilaings assigned to Category A -.ay be of any construction oemttac •- C.oacte- 12A.

’2.4 SEISMIC 3 E-"RMA,NCS 2R V 3 3uildmgs ass’gneo to Category nail conform to ail the -ecu: -“rents ‘‘or Citato - A ano to the accitional rsgui rements ano 'imitations of this Section.

12.4.1 CONSTRUCTION .CMI rATCCNS

Masonry components snail oe constructeo to conform to the limitations

Section.

. ,n . ..we e n;

0»nc

ni-H os.--

.

1 i m;r ; —

jowq .—C

'j wieen grre* reinforce s

i.n e seism;

i an a « ;her so onen

;

(A) DESIGN. Structural and nonstructural comconents

of the building snail be designed and rsinforesa as specified in TaDle 12.1. The numbers desianated 1, 2 and 3 in the Table r»far- subsections

to Seefc4®tw (1), (2) and (3) of 4-g-. 12.2.1(B).

13) TIES. In aaoition to the -ecu; rements of Sec. '2A.5.C. r

, snail oe orovioec around anchor oolts *nicn are set in the too of a ool-.mn : Suc.n ties shall engage the oclts ana at 'east four vent’cal tol-mn oa-s *or masonry. 3ucn ties snail oe 1 oca tea witnin the too - ' tones of one -erce r a consist of not less tnan two No. 4 or three No. 3 ties.

12-3

A180
*

n

m

m

m

<;

:')

5/6 cone

.

12-4-3/M7

( 10-0- 0 )

12-4-4

( 10- 0 - 0 )

H

m

m

m

0

0

5/7

(C) SHEAR WALLS,

of Sec. 12.7.

applicable

Shear walls- shall conform to theT*requirements

iMQ rg ; ; jco i j wea ac

(D) SCREEN wALLS . All screen walls shall be reinforced. Join: r9

^ -forcer., shall be considered affective in resisting stresses. The -nits of a panel snail ce so arranged that either the Horizontal or the vertical joint containing reinforcing is con tinuous without offset. This continuous joint shall oe reinforcea with a minimum steel area of 0.33 square inch. Reinforcement shall be emoeedea in mortar or grout.

Joint rei nrorcing may be conoosec or two wires race wi oh «e i oac trussao wire cross ties. In calculating tne resisting capacity of tr.e system,

and tension in the spaced wires nay be utilized. Ladder wire reinforcing snail spliced and shall oe tne widest that the mortar joint will accommodate allowing

of mortar cover.

The maximum sire

1 of pane l s sha ll be 1 4* squa r e fes c

empress

rQ *

2

~ i nc

with LtlU IlldX illlUlIl ’Jlllimiis tun m either direction o P

1 1 ‘5 feet.—tacn

pa rreA shall b e su pport e d aft -all gag e a by a a t ru e tu r a 1 mem be r

g enerate, mas onry, o r steal. —Supports at the too and anas of the

,ea n<e4

-s-ho 11 be by means of con finemen t of the mason ry by a * l eaat

h^SHneh into a nd b e tween th e fla nges a rs stee l c ha nnel. The

; a pac e between the ond of the panel an d the web or th e c h a n n e l sh atH

I be- at l e a s t 1/2 i n c h a nd 3hal 1 be--

v

-o fd of mo rta n .—The use of ooui -

I /d' Tdii t. configu i anrr g n in other stee l secti on s a r i n maoo nny or

c on ene te ia a eceptabhe.

i te ri z en tai and vo rtical joinee- snail bo not l eas

th a n 1/ 4 inert thick.—All joints shall b e- qoraa lotoly fill ad i k .1 th

, wopi;an and 3 ha 11 b e shav e d j ennas

.

(E) NONSTRUCTURAL COMPONENTS. Nonstructural walls,

partitions, and components shall be designed to support themselves

and to resist seismic forces induced by their own weight. Holes

and openings shall be suitably stiffened and strengthened. Non- structural walls and partitions shall be anchored in accordance

with the requirements of Sec. 12A.2.6.

(F) CONSTRUCTION TYPE. Cavity wall construction

shall not be used £or any structural masonry.

12-4

A181
12-4-5 Committee voted to modify the table and move to seismic performance category C.

Table 12.2

CSJ .NOMINAL MINIMUM THICKNESS OF WALLS.

TYPE OF MASONRY

STRUCTURAL WALLS

Reinforced Hoi

Masonry

ow Uni

t

NONSTRUCTURAL AND PARTITIONS: 1

Urn e i rmrr n fa i u sd Reinforced

Wat'S. whose cJivW structure

function is .XTni ckness

exterior XT for the

enclosure, ^Sapper-most

nonstructi^T 3?Jssfoot

walls^tfnd high paQtion

partitions of wall

HjTrbwcQed C 1 ay Masonry

Stone MaStrmcy^^

^

16 Cavity Wall Maso7Tr>>^ '**' 8 Hollow Unit 3 So 1 idJjiierrTy 8 J>otrfea Masonry

& 6

"

for walls that are net

at are not over three stories

over

thickness of plaster coatings may oe considered in satisi ness rj-eios ana minimum chickness requirements but snail not take stressed

2 Seventy feet for stcTre<^asonry

.

3These thicknesses may be rec 35 feet in total height in buildfn

high

‘These thicknesses ma^£e"reduced to 5 inches for^sc^uted walls and 3 inches for so 1 i^sratonry walls in one-story bui ldings''wta£n the wall i not over ^fe^tin total height, provided that when gab! ectm&£ructi<

is additional 5 feet in height is permitted to the peak

_w?*cTe.

rt£ALt!pi

Nominal 4-inch-thick load-bearing reinforced hollow clay unit masonry

walls with a maximum unsupported height or length to thickness of 27 may be permitted, provided net area unit strength exceeds 8000 psi , units

are laid in running bond, bar sizes do not exceed 1/2 inch with no more

than two bars or one splice in a cell, and joints are flush cut, concave

or a protruaing V-section. Minimum bar coverage where exoosea to weat.ner

ia.v be 1 1/2 inches.

Modify as shown and move K Committee preference

B - Modify as shown but keep in this location

C - Do not modify but move.

D - Do not modify and keep in this location

12-5

A182
4

*

4

n

m

m

N

m

m

m

m

m

G

(/) .MASONRY WALLS . Masonry b e aring wa l l thickn ess s h a ll conform tio (G) wish a maximum h/ 1 ratio of 2 & :

/ Except for walls designed under the provisions of Sections 12A.6.1

land 12A.6.2CA)

e axiai stress

sot exceec the value determined oy the following formula: masonry Searing I S.'.al

f 3 G .20 f n - '-r^-l 3

' n m - 'At'

wnere

f

ffl 3 Compressive unit axial stress in masonry wall.

f* - Masonry compressive strength as determined py Sec. 12A.5.1. The value of f' shall not exceeo 5000 os*.

t = Thickness of wall in inches.

h = Clear distance in inches, oetween sucoortmc or stiffening elements ( vertical or horizontal,.

Effective height different from clear

distance may be used if justified.

Other i '’qu i rcwa n ts a p e opoeifiod in 13Ai

6

. 3(g) .

tf) REINFORCED MASONRY COLUMNS. Every structural wall

o p pio r whose horizontal length is less than two times its thickness shall be designed and constructed as required for columns.

The least dimension of every reinforced masonry column shall not

be less than 12 inches and the maximum h/t ratio snail be 20.

EXCEPTION

"he minimum column dimension may ce reduced to rot less than

3 incnes provided t.ne design is oased .ocn :/2 the allowable

stresses for axial lead. Sending stresses need not oe sc reduced.

The axiai load on columns snail not exceed:

? 3 A 1C. 13 f * 0.55 p f I g

- m

• H

g s' ^ ‘ 13c —

wnere

P 3 Maximum concentric column axial load.

A = ”he gross area of one columns with ceduccicns -or

’ rakes and similar joint treatments.

f^ 3 Compresssive masonry strength as determined oy Sec. 12A.5.1. "he /alue of fC, shall not exceed

5000 psi.

P 3 Patio of the effective cross-sectional area of

y vertical reinforcement to A,.

3

f 3 Allowable stress in reinforcement ; see Sec. '2A.5.2.

t 3 Least thickness of column in incnes.

n = Clear reign: in -Irenes.

Other requirements are specified in 12A.6.3(F).

12-6

A183
12-4-8

(9-0-1)

5/10

cone

.

12-4-9/

M-16

(9-1-0)

5/11

5/12 12-4-10

( 8 - 2 - 0 )

[/) GROUTED MASONRY --MULTIWYTHE. Grouted masonry is that form of construction made with brick or solid concrete units

in which interior joints of masonry are filled by pouring grout

therein as the work progresses. Only Type M or Type S mortar shall

be used.

Toothing of masonry walls is permitted only wnen designed and detailed by the design engineer or architect and only

at approved locations. Racking is to be held to a minimum.

When reinforced in accordance with the following

requirements it shall be classified as reinforced grouted masonry

--mul tiwythe . All required reinforcement except masonry joint

reinforcement and column ties to the- aaiaaqpapB aoiaw shall be embedded in grout. All other reinforcement shall be embedded in mortar or grout. All vertical reinforcement shall be

held firmly in place during grouting by a frame or suitable equivalent

devices. All horizontal reinforcement in the grout space shall oe tied to the vertical reinforcement or held in place during grouting

by equivalent means.

(jO high LIFT GROUTED CONSTRUCTION. For grouted masonry

-mul tiwythe Construction cleanouts shall be provided for each pour

third

by leaving out every QtnO'P unit in the bottom tier of the section

being poured. Other requirements are specified in 1 2A .3.4(3)

.

For hollow unit masonry construction cleanouts snail

be provided for each pour by omitting face shells in the oottom

pour course of each cell to be grouted. The grout shall not^ exceed

16 feet for walls 8 inches or more in nominal thickness nor *S* feet

for thinner walls. A

Other requirements are specified in 12A.3. 6(3).

Cleaning shall be accomplished by means of a high-pressure jet "N

stream of water, air jets, or other approved equivalent procedures.!

REQUIRED STRENGTHS MORTAR iROUT

of Sec. 1 ZA . 8 . 2^_jwwrmom required

500 psi for field mortar

d mortar cubes) un i ess—fcififter strengt.ns

red bv the construction documents.

Note: Item (K) becomes

Item (0) on p. 12-]

by a later ballot.

addition to the

strengths shall be 2000 psi

samples (2000

12-7

A184
12- 4-11

( 10 - 0 -0 )

5/13 12-4-12

( 10- 0- 0 )

K

(X) JOINTS. All hollow units shall be laid with -ace

shell bed joints and head joints filled solidly with mortar for a distance in from the face of the unit not less than the thickness

of the face snells unless more stringent construction is required

by this Chapter, Chapter 12A, or by design. Cross webs and end

shells of all starter courses shall be bedded on mortar. This

applies to units laid on foundations or floor slabs, and all courses

of piers, columns, and pilasters.

Concrete abutting structural masonry such as at starter courses or at wall intersections not designed as true separation joints, shall be roughened to a full amplitude of 1/S

inch, and shall be bonded to the masonry per the requirements of

this Chapter as if it were masonry. Unless keys are provided,

vertical joints shall be considered to be stacked bond.

L (X) GLASS MASONRY. Glass block shall be laid in Types

M, S or N mortar. Both vertical and horizontal mortar joints snail

be at least 1/4 inch and not more than 3/8 inch thick and snail be completely filled.

|

5/14

12 -4-13

( 10- 0- 0 )

Glass block panels snail have reinforcement in the

horizontal mortar joints, extending from end to end of mortar

joints, but not across expansion joints, with any unavoidable

joints spliced by lapping the reinforcement not less than six ,5)

inches. The reinforcement shall be spaced not more than two (2)

feet apart vertically. In addition, reinforcements snail be

i placed in the joint immediately below and above any openings within

a panel. The reinforcement shall consist of two (2) parallel,

longitudinal, galvanized steel wires. No. 9 gage or larger,

spaced two (2) inches apart, and having welded thereto No. U or heavier gage cross wires at intervals not exceeding eight (3)

, inches, or the equivalent approved by the Regulatory Authority. ” $0 REINFORCEMENT DEVELOPMENT, ANCHORAGE ANO SPLICES.

; The requirements of 1 2A .6.3(0) are applicable except that calculated

! stress shall be replaced with yield strength. The following suo-

| sections 1 and 2 replace subsections 5 ano 7, respectively, in

|

1 2A .5.3(D)

.

12-3

A185
5/14

cone

.

-ei r-'oroareno of 4G,2CG os: 'ass onan 12 wn = ra

i • lave looker's .argons* Jjle ^asio oe .a ' oo.-«-o ‘argon, -c- oa*:—sc snail oe a: 'aaso .25 05 -///f. ou: -ot lass o.nan 24 c* -or -e:

- -o.-esra 0 yield stnengtn ncr 260* -'or -elnfcrcerano over 4C,2CC ?S ' y

' a 1 c so-enco -

, -prc.nas -or reinforcing oars ana 5 inenas -or masonry ;oint - ei "-orcer-e-d

a ciamacar of one smaller oar spl'oad,

-.a soacif’lac oar yalo so'angon, ps'.

•n.c.nas.

~sciaoaly s-r-cundi ~g ora 'e’r-'oroe a- •nan one prism sorengo.n, os:

'eve'e pre.ro ’argons “'or p’ain - -ore: rg ;*al ’ oa :.. :a o*ao .

1 -ec

-n- defo'-eo -einforoare.no o.o no: lass or. an ’2 inenas.

12-4-14

( 10 - 0 - 0 )

12-4-15

( 10- 0- 0 )

rcr ae-or—ed -lain oorcress'or -e-r-crcs-sro •- 00 ' . —

are rco oaro of one seismic sysoe'-

, o-asa -a'. as -a,

-e-cocad 00 15c = *or oars o

r' 42,222 os; y‘a’o sore-go - arc 2'd 0 -or oars over 40,222 osi ye': so-ergo-.

In -l e/ oral ner;a-s or at are -00 oaro 0* o*e or: ary lose resisto.ng sysoar o

- a o. .-el opme-o ’argons -a, oa

..rare excess -9 m -ores rare 's o-cveec. r c- onasa oa

2 r^'/ CoS I '/ decani nec csvs : cp.Tgrs 'er~zr.i **/ is *.*s

1 r. w 1 ” 1 C zf T, 0 2 rO £ -7 'Ol - **-**3-3n» C -

** - :c :rac provicea.

1 aaso C .OS 05 - ,•/ . - nor less onar 50 c-

:

-'or -einforoing oars reinforcing snail oa oer-s 5k, f , arc

- y ;

.argons of laps, •> .o noo less o.ra.r -2o 0

r rei nfoncarer 0 o.er

no ? i-cres *or -aso.r

:vcice on at required *o nal 1 oa as oaf ; nao : -

-or oero r~ec oororess'o- -eior'crce'

zr.az are rep :ar:

*ay oe - ecucac 0 : 3Cc- -or pars :f -G,"

arc -5 g

3 *or oars ova- 4Q, 202 os 1 yield

one par

.aided or ~ecrani< :or-aco ; ors snail oa/alo:

rcr oororessicn oars

• sa i s - ’ . sys oar arc a-e sive sorengo.n -eea o

-

’

12-9

A186
5/15

12-4-17/^"

M-18

(9-1-0)

5/16

12-5N /~f

M-19

( 10- 0-0 )

12-6-N T

( 10- 0-0 )

N

(/) DISTRIBUTION OF CONCENTRATED LOADS. Concentrated

loaas shall not be considered to be distributed by metal ties in

stacked bond construction, nor to be distributed across continuous

vertical joints. This provision snail apply when considering

overturning effects in shear walls if stacked bond is not prohibited.

12.4.2 MATERIAL LIMITATIONS.

The following materials shall not be used for any

structural masonry:

Unburned Clay Masonry

Structural Clay Load Bearing Tile

Mortar with Air Cpntents Greater than 15 % Masonry Cement (

' Mortal 1 a n d u es utj «cr yp w t* ei* 5 .

12.5 SEISMIC 3 ERFCRMANCE CATEGORY C

Buildings assigned tc Category C snail conform to all of toe -ecv -•ererts -'or Category 3 and to one additional reauirgnents and limitations of tms Sect'on.

12.5.1 CDNSTRUCTICN uIMITATIDNS

Masonry components snail oe constructed to conform to One limitations of tms

Section.

(A) REINFORCEMENT. All masonry snail oe reinforced masonry conforming to section 12.2.1(B) except for one-storv residences of

running bond construction located in map area 5 shall conform to section 12.2.1(B)2.

(8) TIE ANCHORAGES. In aaoition to t.ne requ’ -ements of Sec. ’2A.5.C C ‘‘or tie ancnoraces , a minimum turn of 135 oegrees 3 1 us an extension of at 'east 5 tie oia.-eta'S out not less than a incnes at t.ne free enc of the tie shall oe creviced.

(C) REINFORCED COLUMNS. In adcition to t.ne reou i rements of Sec. '2.5.C. r -or reinforced masonry columns, no longitudinal oar snal’ oe fart.ner t.nar 5 '"c~es -*-p.m a laterally supportea oar. Except at cprner oars, ties orpvici.ng lateral s-pocrt may oe

•- the form of cross-ties engaging oars at opposite sices of the column.

The tie spacing for the full neignt of masonry s near wall ocuncar cc'.mns

and all other columns stressed by tensile or compressive axial overturning -proas :„e to seismic effects and for the tops and oottoms of all otn.er columns "'or a oistanca of '.5 of clear column neignt but not less than 13 incnes no r t.ne maximum column dimension in" oe not greater than IS oar diameters nor 3 inches. Tie spacing -'or t.ne -emaim-g oo" neignt snail oe not greater than IS oar diameters, AS tie diamete r s, or the ’east oc'.mr dimension, out .not more than '5 incnes.

(D) SHEAR wAlu BOUNDARY ELEMENTS. 3ou;iaary memoers Shall conform to one c* the following:

1. Sec. 11. 3. A wnen of reinforcaa concrete or structural steel.

2. Sec. 12.5.1(C) when of masonry.

.E, JOINT REINFORCEMENT, .ongituoinal masonry jo’ro 'jin fore ament na.. oa uSec

in rgi n fo rc eo grouted masonry ana reinforcec no i low .n:t rasonry only to fu'-'l’ -einforcement ratios but snail not be considered in t.ne determination of theystrangtn of the member. shear

IF) STACKED 30ND CONSTRUCTION. The minimum rjcis of rpr-zontal •'*crce~e ,'0 snail oe D.DC15 for all structural walls of stacked ocnc construction, "'a -aximum spacing

of horizontal reinforcing snail not exceed 2A inches, where -em-orcac no 1 low .r'

t

construction for— s cant of tn.e seismic -es is ting system, t.ne construction s-al' oe crc.te:

solid ana all "ead joints snail oe ,:aae solid through tne use of open e

n o units.

12-10

A187
WALLS

(G) fr iCRG . Every structural wall e* eier in reinforced

,2

masonry construction whose horizontal length is between > and o times its thickness or less than 1/2 the height of adjacent open’ogs

shall have all horizontal steel in the form of ties except that in walls less than 12 inches in nominal thickness and in reinforced

» multi -wyr.h&> u , u , _ , grou ted Tcohst ruction sucn steel may be in one layer in the form of

hairpins

.

(H) HOLLOW UNIT MASONRY. Hollow unit masonry construction, where certain cells are continuously filled with conc-ete or

l grout, and reinforcement, in accordance with 12.2-2* (B) (3) , is embedded therein shall be classified as reinforced hollow unit

masonry. Reinforced hollow unit masonry shall generally be one wythe in thickness. If constructed of more than one wythe, each

wythe snail be designed as a separate element or wall or the wythes

shall be bonded together by means approved by the Regulatory Agency.

This bonding shall be designed so the wythes snail act as a unit.

Vertical cells to be filled snail have vertical

alignment sufficient to maintain a dear, unobstructed continuous

vertical cell measuring not less than 2 inches by 3 inc.nes. If walls are battered or if alignment is offset, the 2 inch by 3 inch clear opening shall be maintained as measured *rcm course to course.

(I) BOLT PLACEMENT. 3olts shall be accurately set wie fi te»p lateO' "»p ey >p?foveq oq w4-»aiQf>t moano and neid in place to prevent movement.

Vertical bolts at the top of and near the ends of

reinforced masonry walls shall be set within hairpins or ties located

within 2.5 inches from the top of the wall. See Sec. 12A.5.3(F1

and 12.4.1(3) for bolts at the top of -awt, pilasters and co’umns.

^4jjSHRINKAGE OF CONCRETE UNITS. Concrete mascxu^---—

units used for strucTTraf---aui^oses snalJ_JiauMH-ff'TflSximum linear

shrinkage of 3.065 percejU^-?«3Tir^TiesTLtmii^ to the oven-dry

rnntti f "

Mores: Item I, unchanged, also

becomes Item D on p. 12-14. Item J becomes Item E on

p. 12-14.

12-11

A188
(K) GROUT. Grout shall have a consistency, considering

the .methods of consolidation to be utilized, to completely fill all spaces to be grouted without segregation except that slumps shall

not be less than <1.5 inches for all grout, we* mono t h an m3 in s h a t

ft. f. II n m n inr^f -nar-cn gyrMif

Mixing equipment and procedures shall produce grout

with the uniformity required for concrete by ASTM C94.

SPECIAL

(L) ALLOWABLE STRESSES WITHOUTA INSPECTION . The allowable

work without special inspection

stresses for tfe i n o p eofro d nainfa nsed r nnrf rurtiQn shall be those

given in Table 12A.5 except that the factor of 2/3 for axial compression in walls and columns shall be reduced to 1/2.

(M) CORE TESTS FOR SHEAR BOND IN GROUTED MASONRYMULTI WYTHE. In addition to the requirements of Sec. 12A.3.3 the

core tests for

following provisions must be met for grouted masonry-mu 1 tiwythe

construction when such tests are required.

The unit shear strength shall not be less than 100

psi. Where an unusual number of cores fail during the cutting

operation, the design authority shall determine if the test program

is extensive enough to satisfy the requirements of Sec. 12A.1.5.

One test series shall be made for each 5,000

square feet of wall or equivalent but not less than one series for

any building.

(N) MASONRY WALLS. Masonry wall thickness shall conform

Co table 12-2. The ratio of height or length to thickness of reinforced

, structural walls shall not exceed 25.

(O) Insert Item (K) from p. 12-7.

12.5.2 MATERIAL LIMITATIONS.

structural

The following materials shall not be used for any

purpose

Bu i ldi n g QH c fc and Hollo w Bri c k maaa fram Cl ay ar Shale a f Gnado MW Sane re de Building Bwok a n d S a il'd L a i r3 «daa r.i nc

G enerate -Haswy’-Uni to oth e r th aa . ir adftN

Hollow Load-bearing Concrete Masonry Units

other than Grade N Ba n d

- li me Bu i l ding Sr i ok other tha n .jr aaas iU a fta-aw

Type N Mortar

Masonry Cement

12-12

A189
5/25

( 10- 0- 0 ) z

The following materials snail not be used for any

nonstructural puroose:

-Q 1 ass ^Jrrfts- '

! Unourned Clay Masonry

Structural Clay Load-bearing and Nonl oao-bearing

(9-0-1) T

( 10- 0- 0 )

12.5

Wall Tile

Masonry Cament (Mortar with Air Content Greater than 15%)

W&r~.-drr- Types-^r -Q-*ad—)C

3uiidings assigned to Category C snail conform to all of sne requirements -or Category C and to tne aacitional requi regents and 1 imitations of t.n : s Section.

12.5.1 CONSTRUCTION LIMITATIONS

Materials for mortar and grout for structural masonry snail oe measured in suitable calibrated devices. Shovel measurements are not acceptable. An approved ad- mixture of a type that reduces early water ioss and produces a net expansion action snail

. be used for grout for structural masonry unless it can be demonstrated that shrinkage

cracks will not develop in the grout. The thickness of the grout between .masonry units

and reinforcing shall be a minimum of 1/2 inch for structural masonry.

(A) MINIMUM 3R0UT SPACE FOR 3RCUTE3 MASONRY. 'he rir-num grout soace 4:r

structural reinforced grcutec masonry snail oe 2-1,2 mc.nes for 'ow--*t cons t.-.ct' cr. arc 3-1/2 inches for nigh-lift construction.

5/26 (a) REINFORCED nOLLOW UNIT MASONRY. Structural -ei--'orcec -c"ow .nt -asor-y

shall conform to -equi remerts telow:

1. Wythes ana elements shall oe at 'east 3 Irenes nominal : with clear, unobstructed continuous vertical cel’s, wit.-.out of*se:s, 'a-ge ere.g enclose a circle of at least 3-1/2 inc.nes in diameter arc »itn a ni n '.mum area of

i nc.nes

.

2. All grout snail oe coarse grout. Srout consol idat'on $~a' oe :/ .mechanical vibration only. All grout snail oe raconsol 1 catec after excess cst.-e -as been absoroed but before workaoility nas oeen lost.

3. Vertical reinforcement snail oe securely neid *n oosition a: :o:s. bottoms, splices, and at intervals not exceeding '12 bar diameters. Aoproved "te — ecate

centering clips or caging devices snail oe -sec in nig,n-’ 1ft construction, as -eo-nec. :o hold the vertical Oars, horizontal wall -ei nforcement snail oe securely vac to on €--

tical reinforcement or neid in olace during grouting Ov equivalent means.

A. In wytnes of less than 10-incn nominal tni excess , > ary ercica’

cell, there snail Oe a maximum of one No. 1C oar or two No. 3 oars wit- soloes stagce-ec

for the two-oar situation.

5. 'he first exceotion of Sec. 1 ZA .5.3(F) snail not as sly; minimu.m i nominal column dimension snail oe 12 inenes. i

cx-ess

12-13

A190 I

I
'0 STACKED 3CN0 CC.’iSTRUCTI C.N . All stacked bend construction snail

to tne following r=cu ; rsnents :

1. The minimum ratio of horizontal -91 nforcement snail oe D.CC13 far roni;,} structural masonry and 3.0025 for structural nasonry. The Maximum spacing of Horizontal reinforcing snail not exceed 24 inc.nes for nonstructural nasonry nor 16 inc.nes for structural nasonry.

2. Reinforced nollow unit construction wnicn is part of one seismic resisting system snail (1) be grouted solid, (2) use oouOie open end ,H plocx, -nits so that all head joints are made solid, and (3) use bond oeam units to facilitate tr.e flow of grout.

5/26

3. Other reinforced nollow -nit construction used structurally, Put not part of the se made solid cy smic resisting system, snal 1 the -se of open end units.

pe grouted solid ana al 1 read joints snal 1 :e

(10-0-0) (D) Insert Item (I) from p. 12-11 reinserting the phrase "with templates

(7-1-2)

, (E) Insert Item (J) from p. 12-11.

(10-0-0) (F) Insert Item (K) from p. than 10 inches for fine

12-12 reinserting

grout or 9 inches

the phrase "not more

for coarse grout."

12 - 8-1

M-28

( 10- 0- 0 )

12.5.2 iAl cAIAL LuMI irti i-ilS cada i'i

, a

-- - - -- -- -sec. Sans- 1 ire J as®."-- *£ui Idir.g £rick and

, o f. h a r 4n a n gr ade .M , Hollow nonload-oear-nc concrete nasonry units sn a_il not oe ouilding orick^ sn*!! r e t :a .i»a ;ny itr- Hollow Brick made from Clay or Shale of Grade MW and Building 3rick and

Solid Load-bearing Concrete Masonry Units other than Grade N snail not

be used for any structural masonry.

12.5.3 SPECIAL INSPECTION

Special inspection snail oe provided for ail structural nasonry.

12.7 SHEAR WALL REQUIREMENTS

Shear walls shall comply with the requirements of tnis Section.

5/27

12-9 (

( 10-0- 0 )

;

12-10

( 10-0-0 ) _1

12.7.1 REINFORCEMENT The following reinforcement requirements apply to snear walls required to comply with the provisions of 1 2. 2. 1 (3 ) ( 3 )

.

The minimum ratio of reinforcement *or snear walls snail oe 0.CC15 ! n eacn direction. The maximum spacing of reinforcement in eacn direction snail oe tr.e smaller of the following dimensions: one-third tne length and heignc of the element out net more than 48 mcnes. The area and spacing of reinforcement perpendicular to tne snear reinforcement

snail oe at least equal to that of the -equired snear reinforcement. The portion of tr.e rei nforcement -equired to resist snear snail be uniformly distributed.

5/27

cone.

EXCEPTION:

For snear walls constructed using running oona, the -at! a of -em-'orcenerc

may oe aecreasea to 0.0007 provided that ail shear is -esistec oy tne reinforcement. The sum of tne ratios of horizontal ana /erticai •_ ein- forcement shail not Pe 'ess tnan 0.002.

12-14

A191
12 - 10-1

( 10- 0- 0 )

M-29

( 10-0-0 )

Reinforcement required to resist wall shear snal 1

be terminated with a standard hook which terminates beyona the

boundary reinforcing at tne end of the wall sections. T he nook

may be turned up, down or horizontally and shall be embeodeo in mortar or grout. Wall rei nforcement terminating in ooundary

columns or beams shall be fully anchored into the boundary elements.

Vertical stresses in shear walls shall be dete rmined

from the combined effects of vertical load and from the overturning

effects of lateral loads. Minimum vertical loads shall be consioereo.

Formula 3-2a shall be used for unreinforced masonry design.

In computing the shear resistance of the wal’, only

the web shall be considered. For unreinforced masonry tne aepth

of the web may be considered out to out of flanges.

12.7.2 BOUNOARY MEMBERS

Where cross walls or boundary members form a part of :.-e snear wa' s./scer. one intersections snail oe constructed as reouired £ or tne walls chemsel/es. Connections to concrete shall conform to Sec. 12A.2.1. Where the oouncary nemoers are of struct-ra"

steel, the shear transfer between the wall and the boundary nemce- snal' oe ceve : ocec :

y

fully encasing the element in grout, by dowels, bolts, or snear lugs, or oy similar approved methods.

When the structural system, as described in Chapter 3 and ~aple 2-5, tens - cos of substantially complete /ertical loao-carryi ng frame, ooundary memoers snal ' :e provided

at each ana of the wall. The members snail oe of tne same constrjct'on as the ‘-ame columns. Where the frame is a special moment frame, those columns sra" conform to ere requirements for suen memoers in Chapters 10 and 11. Also see Sec. '2.5.' C *or Saceocr.- CiO.

The required vertical boundary memoers and suc.m other similar vertical e' e^e^ts

as may be required shall be designed to carry all tne /ertical 'trees -“suiting *-ox tre

wall loads, the tributary dead and live loads, ana tne seismic 'trees prescn'tec - n these provisions

.

Horizontal reinforcing in the walls shall oe anchored to the /e-tica' e'enerts Where the boundary element is structural steel this snail be accompl •' snec oy welding or oy extension , with bends if required, into grout fully surrounding tne column.

>*-30 12.7.3 SOHPRCODIVC STRESSES

( 10- 0- 0 )

,

For loading combinations including in-plane seismic 'trees, allowaole compression stresses at any point snail not exceed those allowed *cr ax

- a' cc-oress'c-.

For unreinforced .masonry designed by Sec. 12A.S.1, the allowable worx-ng st-ess -a'-es are given in Table 12A-3. The allowable working stress values for reinforced -asonry sna'" ce the allowable working stresses given in Table 12A-5 ano aoplicaole -educt'c-s *cr slenderness effects snail apply. The minimum horizontal distance between 'ate-a' s.ooc-ts

may be considered for walls as well as the minimum vertical distance. ror-ula 'LA-t cr.a" not be used.

12-15

A192
EXCEPTION:

For pier type wall elements that do not extena From floor to floor compression stresses under combined loading at any point may be limited to those alloweo for flexural compression provided that Formula 12A-7 is also satisfied.

12.7.4 HORIZONTAL COMPONENTS 5/27 When shear reinforcing is required for loads that include seismic effects ana diagonal bars conforming to Sec. 12.4.6.4(0) are not provided, reinforcement approximately

perpendicular to the required shear reinforcement shall be provided equal in amount and soaced not furtner apart than is required for the shear reinforcing. Horizontal rein- forcing snail ancnor into or be continuous through the pier elements. Horizontal components

may De separated from the shear wall system by means of joints. The joints shall provide for building movement determined in accorcance with Sec. 3.3. The Horizontal components snail be anchored to the building and designed as otherwise required by these provisions.

12-16

A193
TABLE 12. DESIGN AND REINFORCEMENT

REQUIREMENTS FOR SEISMIC

PERFORMANCE CATEGORY B.

Map Area 2 Map Area 3 Map Area 4

Type of Construction

Buildings

under 35 ft Bui ldings over 35 ft Buildingsunder 35 ft Buildings over 35 ft Buildingsunder 35 ft

Bui ldings over 35 ft

Structural Components

Running Bond 1 /' 2 2 2 3 Stacked Bond 2 2 3 3 3 3

Nonstructural Components

Running Bond 1 1 1 1 2 2 Stacked Bond 1 1 1 2 2 2

Note: 12-11-1 F

(9-0-0)

1 Abstain

1. The numbers 1, 2 and 3 refer to subsections (1) , (2) and (3) of 12.2.1(B)

2. Map areas refer to figure 1.2.

12-17

A194
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age 2-

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"33 • > CQ O I a cj

0) Qu3

"333 3 *3 O C

£3 II I<I 3

00

-3 "3 5 3 X

“Ti-3 3 —

'.0 3 —

-* 3

00 3 —• 00 3 2 3 "UC 3 — S — 5 3 C

CO 3 J ^ ^ “3 | -3 i

CO -3 3 ^ - 3 3 3 —• O 3 M

a. 3 3 —»

'J JO 3 3 3 t- 1 X

U 3 3 — c • a.

“3 -3

C 3 3 3 m 333 — — 3 3 <r 3 cnj

AI96
u

V

a.

to

cj

i

V

"jC jo a-
Page

4

-

Chapter

12

A198
BB’ B’ BB1IBI0

MS000 i
Page

6

-

Chapter

12

(

A200
COMMITTEE 6
JOINT BALLOT NUMBER 6/1

PROPOSED CHAN(17

TECHNICAL COMMITTEE: #6 - —Steel

COMMITTEE

ATC-3-06 SECTION REFERENCE: 10.2

Change the seventh and eighth line to read as follows:

"...members or structural systems."

ITEM NUMBER: P

B

"Connections which do

structural systems..."

not develop the strength of the member or

FINAL BALLOT:

Q ABSTAIN

1 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

These changes reflect the

the full capacity of their

cas es where members

cross section.

need not develop

P

P

P

P

A202
—' IEW AND REFINEMENT q F TEXT attit

PROPOSED CHANnr

JOINT BALLOT NUMBER 6/2

1LISMIC PROUT^mvc

TECHNICAL COMMITTEE: #6 . Sfao , ATC-3-06 SECTION REFERENCE: 10.2.1

Delete 10,2.1 (B)

10 ' 2a (C) “«* “.2.1 ») to 10.2.1

Add new 10.2.1 (D)

In AISC specifications 2.5, substitut

COMMITTEE ITEM NUMBER

(B) and 10.2.1 (C)

,

e V

u 1 0-68 in lieu of V < r0.55.

PINAL BALLOT: .5 YES

Q NO

0__AB STAIN

I DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

^-“-^Plon of sec. 10 2 l /'T3\ AISC Specs, which i , 1S Prevent the use of Ea (7 s i \ The committee record* “It'STM all0Wable “

to‘(0.55 F )1d (0.68 F ) td.

th3C Ch£ ““TM» ^IT-able shear be leased Addition - ox sec in ? i is also to-be

A203
JOINT BALLOT NUMBER 6/3 —IEW

^

REFINEMENT OF TENTATIVE SETCMTC PROVTSTn-.-s

PROPOSED CHA.NCF

TECHNICAL COMMITTEE: //6 , Steel

AT C- 3 -06 SECTION REFERENCE: 10.4

COMMITTEE ITEM N"M3ER

Delete sec. 10.4.1

frames ,

S

space^frames°in

ebui lding "frame "s

read “ follows: "Ordinary moment

in bearing wall systems shall be designed^H

3 ’ “d SPaCe frames incorporated

Ref- 10.1, Part 1 or Ref. 10.2 or Ref 10.“" COnStructed in eccordance with

FINAL BALLOT : 5 YES

0 NO

0 ABSTAIN

1 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

Combine two separately stated requirements into one

A204
APPENDIX B

m

m

n

m

*

a

INSTRUCTIONS FOR THE

JOINT COMMITTEE BALLOT

The Joint Committee ballot was conducted in two stages. The instructions

for these two ballots were conveyed in two letters from the chairman,

E. 0. Pfrang, dated July 18 and July 24, 1980. These two letters and

their attachments (exclusive of the actual ballot sheets and ballot items) are included in this appendix.

*

M

II

*

«

JOINT BALLOT NUMBER 6/4

MVIHU^MFINEMENT OF TENT4TT„t 5EISMT C PPnuTcTAnn

PROPOSED CHANOr

TECHNICAL COMMITTEE; »6 , Steel

ATC-3-06 SECTION REFERENCE: 10.5.1

COMMITTEE ITEM NUMBER;

Change the "exception" to reed as follows:

1

2.

Performance ^tego^'c^y ^'^dTna^^ent “ SeiSmiC “ —Performance

Ri-NAL ballot : 5 yes

0 NO

0 ABSTAIN

1 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

une-si

Addition of

t "Lcep“on

b

2"

1

refl«trther

f°raed

h

WeU dUrlDg earr hquakes of sec. 3.3.4 and 3.3.5.

reIleCtS these oase histories, and the intent

A205
JOINT BALLOT NUMBER 6/5

PROPOSED CHAMnr

TECHNICAL COMMITTEE: jf 6 . SteM

ATC-3-06 SECTION REFERENCE: 1 0 . 6 . 3

COMMITTEE ITEM NUMBER;

Change the third line to read "ay-fa 1 f not exceed 0.75 P

" 3X131 force m the columns shall

y

’

FINAL BALLOT: 3 YES

2 NO

0 ABSTAIN

.1 DID NOT VOTE

COMMENT ON PROPOSED CHANCE:

Modifying the 0.6 factor tn n if

specifications (1979). Since ' the^^^AIS^

16 ^

the change in che AISC

sr ffssr

evaluate its impact by trial designs.

* 1S ~ ac " 0r De keP c as °-6 and

I

A206
J U liN i OALi

HlIj^LAND REFINFMFM-^t OF

^

TENTATTvp £NTATI,1L-SEISMIC PROVTqrnvc

PROPOSED CHanct

TECHNICAL COMMITTEE: #6, Step!

AT C- 3-0 6 SECTION REFERENCE: 10.6.5

COMMITTEE ITEM NUMBER;

T"

the first line ai

- £er che equation to read ^

foiiows;

m place of Equation 1; 15-2 of Ref. lo.l."

FINAL BALLOT: 5 YES

0_NO

0 abstain

. ^ DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The committee felt that- „ a siller form is desired. However IhTTM^ C °° '-P^-c-d. and

Che equation in its present fn- . 'a ” c0TM

lctee agreed to retain

trial design phase. Because the Lay'^r^ch th“

durin S Che

with

^^1011 Sh°Uld re P lace only AISC Eq 1 15-7*

equ

J

tion derived uckmg of the column "web.

q ' 1 * 15 " 2 Which is concerned

A207
COMMITTEE 7

A208
JOINT BALLOT NUMBER 7/1

B|

m

m

it

m

m

RZVIEU AND REFINEMENT OF TENTATIVE SEISMIC PROVT e IOVS

PROPOSED CR.-'' ; ~ r

technical cocmttee: #7, wood committee item nipze?.:

Add new references:

9.15 Plywood Design Specifications, APA, 1978

9.16 Plywood Diaphragm Construction, APA, 1978

FINAL BALLOT: 5 YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

Plywood working stresses are included in the Plywood Design Specification

It will be necessary in some cases to check the shear strength of plywood

in order to design a plywood diaphragm by the principles of mechanics.

This information is not contained in any of the other references in

Chapter 9.

e

A209
JOINT BALLOT NUMBER 7/2

REVIEW ANT REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PRC,T5nc I

r'

1 CHAN

r

TECHNICAL COMMITTEE: »7, Wood committee ITEM NITCSEE: 2

ATC-3-06 SECTION REFERENCE: 9.1

Change Reference 9.12 Co read:

One- and Two-Familv Dwelling Code , 1975*

*One of the affirmative voters made an editorial note that the latest edition

of this code is 1979 .

FINAL BALLOT: _2 YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

As written in 9.12, it appears as though each of the three model codes has

a one- and two-familv code. The One- and Two-Family Dwelling Code is a single document written by the four model code organizations, the three

listed in 9.12 plus the American Insurance Association.

c

A210
JOINT BALLOT NUMBER 7/3

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

TE'rZwCAL CO' TEL :

; *7, Wood COMMITTEE ITEM NV2rr • 3(A)

AT 0-3 -06 SECTION REFERENCE:

Change the capacity reduction factor, p, for shear on diaphragms and shear

walls, from 0,75 to 0.85.

FINAL BALLOT : 5 YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The change was suggested on the basis of the results of a diaphragm test

program conducted by the American Plywood Association. It was found that

the average load factor against failure was 3.65, which exceeds the product

of the multiplying factor, 2, (see Section 9.2) times 0.85 by more than 2.

In light of this comparison, the Committee agreed to increase the value of

6 from 0;75 to 0.85.

A211
JOINT BALLOT NUMBER 7/4

REVIE'.' AN’T RE r INEMEN7 OF TE"TATT VE SET?v'7 r PF""IS7""' C

PROPOSE! CHANCE

tec^ecical co:j::ttee; #7, wood committee itew

AIC-3-0o SECTION REFERENCE: 9.2

Revise the tabulation of strength reduction factors as follows:

All stresses in wood members i = 1.0

Bolts and other timber connectors

not listed below itI-* o Shear on carriage bolts not

having washers under the head 6 = 0.67

Lag screws and wood screws 6 = 0.90

Shear on diaphragms and shear

walls as given in this chapter i - 0.85

7 (

' J \ .

FINAL BALLOT: YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The change deletes the 6 values for nails in shear in plywood diaphragms of

Group III species members («$ = 0.82) and Group IV species members ($ = 0.55'

because these values are included in Tables 9-1 and 9-2 of ATC-3-06. The © value for shear on diaphragms and shear walls was changed from 0.75 to 0.35

per Committee Item No. 3(A).^ The two previous values of 6 (0.90 & 3.6/N)

for lag screws and wood screws were changed to a single value of 6 = 0.90.

A212
JOINT BALLOT NUMBER 7/5

i

»

1

1

1

9

m

m

m

REVIEW ANI REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANGE

ir 7 , Wood

AT 0-3-0- SECTION REFERENCE

Delete this subsection.

9.4.1(c)

FINAL BALLOT : _5 YES

N O

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

This change was approved in view of the fact that the 1577 edition of the

National Design Specification (Reference 9.1) has covered this requirement

tf

*

A213
JOINT 3ALLOT NUMBER 7/6

an: refinement of tentative SEI Sv‘r " °R' rc '’D*'S

p

p; - Dncrj CH.-N-E

CC.'D'.ITTEE

If 7 , Wood \*”A/r TT

ATC-3-0- SECT! ‘N REFERENCE: 9.5.3(A)

Replace the existing language with the following: Reference 9.1 snail be

modified as follows: In 8. 3. 1.4, replace the existing language with

"’When more than one nail or spike is used in a joint of a frame or similar

component, the total design value shall be determined in the same manner

as is done in 8. 3. 2 .3." In 8.8.6, change two -thirds to one-half .

FINAL BALLOT : 4 YES (1 with comment)

1 NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The opinions of the negative voter were that: 1) Section 3.3.2.

3

of the

National Design Specification (NDS) does not apply to nails; thus the

proposed change is inappropriate and is not substantiated, and 2) there

is no justification for the suggested change in NDS 8.3.6 since the twothirds factor has been in the NDS since its inception. The affirmative

voter that had comments was of the opinion that Committee 7 should be

hesitant to reference the NDS and then to suggest changes in the NDS.

He also felt that the modifications suggested for the NDS were based on "gut" feelings rather than fact.

t

A214
4

4

4

4

4

4

4

4

4

4

JOINT BALLOT NUMBER 7/

7

REVIEW AN! REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSED CHANCE

;EE: »i

ltl. Wood COx O

,

'r ^'“ rr I‘'"rv

ATC-3-06 SECTION REFERENCE: 9.5.3(B)

Remove this subsection and transfer it to Section 9.6.3.

FINAL BALLOT : 5 YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The Committee agreed with the imposition of special requirements in Category D

construction in so far as plywood over gypsum sheathing is concerned. It was

felt that prohibiting the use of gypsum sheathing as a part of the seismic

resisting system was not justified for Category C construction. This opinion

was based on the results of some shear tests on walls using plywood applied

over gypsum wallboard. The average load factor obtained in the testing

program was greater than 4.5.

4

4

*

4

4

4

r

A215
JOINT 3ALLOT NUMBER 7/8

review ant refinement OF TENTATIVE SEISMIC provisions

p p.

-

' c tjj r

• 17 , Wood COMMITTEE ITEM NOME

AT C-3-0r SECTION REFERENCE: 9.6.3

The existing sentence in subsection 9.5.3(B), without the heading, shou

become the first sentence in Section 9.6.3.

FINAL BALLOT:

NO

‘abstain

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

A216
JOINT BALLOT NUMBER 7/9

n

*

*

REVIEW ANT RETIREMENT OF TENTATIVE SEISMIC PROVISION?

PRO?OS EE CHANGE

TEE -EC I CAL COM'ITTEE : #7, Wood COMMITTEE ITEM NUMBER

AT C- 3 -06 SECTION REFERENCE: 9.7.1(A)

Section 9.7.1 can be modified as follows: ...provided at not over 6 feet on center for buildings two stories, 2Q': feet, or less in height and at not

over 4 feet on center for buildings over this height but three stories, or

35 feet or less in height . Anchor bolts shall have a minimum embedment of

8 diameters.

FINAL BALLOT : 3 YES

2 N O

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The proposed change was predicated on the fact that the Uniform Building

Code has permitted anchor bolt spacing of 6 feet for many years with no documented detrimental consequences in recent earthquakes including the

1971 San Fernando, California Earthquake. One minority view was that in

the Great Alaska Earthquake there were some sill/ foundation anchorage

failures caused by undefined forces. Until we know what kind of forces

are acting, the anchorage requirements should be more, rather than less,

conservative. A second view was that bolts should not be less than 5/8 in

diameter at 4

? 0" on center with at least 7 in embedment. The need for

strengthening the anchorage provision was also suggested by a member of

Technical Committee #9.

*

m

*

*
JOINT BALLOT NUMBER 7/10

REVIEW ANT REFINEMENT OF TENTATIVE SEISMIC P? r'VI ST°N3

PROPOSE!1 CHANGE

ik 7

,

Wood COMMITTEE ITEM NLT2E?.

ATC-3-06 SECTION REFERENCE: 9.7.1(c)

Delete the word "stud" at the end of the sentence and add the following

" . .

.

studs unless specifically excepted in Section 9.7.3 .

FINAL BALLOT: YES

NO

1 ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

A218
JOINT BALLOT NUMBER 7/11

1

*

*

*

REVIEW ANT REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

PROPOSER CHANGE

~ ~ '-M ~ C AL CC'

^ —TEr * #7 , Wood C

r' vrx'I"i'TEE ITEM \yjMBr ' • 10

ATC-3-06 SECTION REFERENCE: 9.7 .2(B)

Add the sentence: "Blocking need not be provided at horizontal joints."

FINAL BALLOT : YES

NO

1 ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

It was the view of the proponent of this change that for conventional lighttimber construction it is not necessary to block horizontal joints in plywood

sheathing. The primary basis for this opinion was the results of four tests

on walls which were sheathed with 5/16" cedar panels. The minimum ultimate

load obtained for these Group IV species (i.e. the lowest strength group

recognized for sheathing applications) was 4400 lb. It is implied that this

magnitude is sufficiently high to preclude the failure of the plywood bracing

panels

.

m

m

m

m

*

A219
JOINT BALLOT NUMBER 7A2

r-; jrr;|;rvr'7 0r jj"p»*TiT3\'r SEISMIC PR.'

pp.^n-yrp CHANGE

TECHNICAL " ‘ C'""! - ” : # 7 , Wood comm 1 1

ATC-3—06 SEC * ION REFERENCE: Table 9 1

o Change the table heading to read: ALLOWABLE SHEAR IN POUNDS PER FOOT FOR

HORIZONTAL PLYWOOD DIAPHRAGMS WITH FRAMING OF DOUGLAS FIR-LARCH OR

SOUTHERN PINE 1

The entry under lOd nails should be corrected from 3/8" to 5/

8

"

1 Revise Footnote 1 as follows: Space nails 10 inches on center for floors

f c al ono l nformorli afo f ranino momKor-c

Allowable shear values for nails in framing member of other soecies set

forth in Table 8 . 1A NDS (REF. 1) shall be calculated for all grades bv

multiplying the values for nails in STRUCTURAL I bv the foil owing factors

Group III, 0.82 and Group IV, 0.65.

o Change the wording under the column heading "ELOCK DIAPHRAGMS" to read:

Nail spacing at diaphragm boundaries (all cases) , at continuous panel * edges parallel to load (Cases 3 and 4) and at -all panel edges (Cases 5 and 6 .

FINAL BALLOT: _5 YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

This set of editorial changes is necessary to make Table 9-1 agree with

Table No. 25-J of the 1979 Edition of the Uniform Building Code.

c

A220
JOINT BALLOT NUMBER 7/13

4

*

4

4

4

4

4

REVIEW ANT REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

prTT>nqr"i (y-i^ytT

J-.L CO v' rv 'ITTEE : #7, Wood COMMITTEE IT rv L"'v,r ~-

AIC- 3-C~ SECTION REFERENCE: Table 9-2

Revise the table as shown on the attached sheet.

*

*

4

4

FINAL BALLOT: 5 YES

NO

ABSTAIN

D ID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The table was updated to agree with Table No. 25-K of the 1979 Edition of

the Uniform Building Code. This is primarily an editorial change involving

the re-arrangement of columsn with no changes in the numbers in the table.

The previously omitted allowable shear value (200) for siding attached with

8d nails at 4 inches on centers was inserted.

A221
-3w£

a

-3

*3

&

«•u

ra

~ s. w

y =

C 'a

e

3

C

•» -3

w

A222

foi

other

luiulmom

and

plywood

llikkncitri
JOINT BALLOT NUMBER 7/14

*

«

*

«

*

m

m

REVIEW ANT REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

T?T7'~'TT /"'>CV‘'rT C'~L x

' f

TEEM: I CAL COMMITTEE: </7, Wood COMMITTEE ITEM NUMBER:

AIC-3-Oo SECTION REFERENCE: 1.3.1 _ Modify the last line to read ’'conventional light timber construction as permitted in Section 9„.5 "

FINAL BALLOT: 3 YES

1 NO

ABSTAIN

1 DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The revision subjects one- and two-storv wood frame dwellings, not over

35 feet in height and located in areas having Seismicity Index 3 or 4,

to the requirements of Seismic Performance Category C (Section 9.5). As

was indicated by the person not voting, the intent of the change is not

clear. The negative voter was strongly opposed to this change in that

he felt the provisions of Section 9.7 as presently required are more

than adequate to assure a safe building.

A223
JOINT BALLOT NUMBER 7/1

REVIEW ANT REFINEMENT OF TENTATIVE SEISMIC PP^'ISITNS

PROPOSED CHAN ~E

TE 7:2' I CAL COMMITTEE: #7, Wood CC 'ITT EE ITE" NUMBER : 1-

AlC-3-Oo SECTION REFERENCE: 14 • 6

o

.) Add to the reference documents: 1) Plywood Design Specification, 1973, A?

A

and 2) Plywood Diaphragm Construction 1978, APA.

4

FINAL BALLOT: _5 YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

This is an editorial change.

A224
1

COMMITTEE 8

A 225
JOINT BALLOT NUMBER 3/1

2.0 Committee Actions

2.1 Recommendations for Change

TECHNICAL COMMITTEE: //8 ARCHITECTURAL COMMITTEE ITEM NUMBER: 1/1

MECHANICAL & ELECTRICAL

ATC-3-06 SECTION REFERENCE: 8.2.5

First Letter Ballot

Item 1“Section 8.2.5 to read: "Transverse or out-of-plane bending or deformation

of a component or system which is subjected to forces as determined in

Formula 8-1 shall not exceed the deflection capability of the component

or system"

FINAL BALLOT: 8 YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE

The change is suggested as a more performance approach to cover, a broad

range of materials.
JOINT BALLOT NUMBER 8/2

TECHNICAL COMMITTEE: #8 ARCHITECTURAL, COMMITTEE ITEM NUMBER: 1/2

MECHANICAL & ELECTRICAL

ATC-3-06 SECTION REFERENCE: Commentary 8.2.5

First Letter Ballot

Item 2

Commentary 8.2.5, third sentence to read: "This is particularly important

for systems composed of brittle materials and/or low flexural strength

materials .

FINAL BALLOT: 8 YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

This change is editorial and was made for consistency.
JOINT BALLOT NUMBER 3/3

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS PROPOSED CHANGE

TECHNICAL COMMITTEE: #8 ARCHITECTURAL COMMITTEE ITEM NUMBER: 1/2

MECHANICAL & ELECTRICAL

ATC-3-06 SECTION REFERNCE: TABLE 8-B

First Letter Ballot

Item 3“Table 8-B Footnote 4 changed to read: "Shall be raised one performance

level if the area facing the exterior wall is normally accessible within

a distance of 10 feet plus one foot for each floor height."

FINAL BALLOT: 8 YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

Footnote 4 changed to be more specific with regard to appendages and

accessibility to areas near the appendages.

A22S
JOINT BALLOT NUMBER 8/

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS PROPOSED CHANGE

TECHNICAL COMMITTEE: #8 ARCHITECTURAL COMMITTEE ITEM NUMBER: 1/4

MECHANICAL & ELECTRICAL

ATC-3-06 SECTION REFERENCE: TABLE 8-B

First Letter Ballot

Item 4

e Table 8-B: Change entry "Veneers” to ’’Veneer Attachments"

FINAL BALLOT: 8 YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

Editorial change to better reflect the intent of the entry in Table 8-3

which is the "attachments” rather than the vaneer.
JOINT BALLOT NUMBER 8/

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS PROPOSED CHANGE

TECHNICAL COMMITTEE: // 8 ARCHITECTURAL COMMITTEE ITEM NOT: 2/1

MECHANICAL & ELECTRICAL

ATC-3-06 SECTION REFERENCE: 8.1

Seond Letter Ballot

Ballot Item 1

(New exception to be added to Section 8.1)

Exceptions

3. Elevator systems which are in buildings assigned to Seismic Hazard

Exposure Group I and are located in areas with a Seismicity Index of

1 or 2 or which are in buildings assigned to Seismic Hazard Exposure

Group II and are located in areas with Seismicity Index of 1 are not

subject to the provisions of this chapter.

FINAL BALLOT: YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

The additional "exception" was appropriately added to Section 8.1 so that the exceptions would be in one place. This new exception couid have

been placed in the new Section 8.4 but it was decided the better location

would be in Section 8.1.

A2 30
JOINT BALLOT NUMBER 8/6

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS PROPOSED CHANGE

TECHNICAL COMMITTEE : // 8 ARCHITECTURAL, COMMITTEE ITEM NUMBER: 2/2

MECHANICAL & ELECTRICAL

ATC-3-06 SECTION REFERENCE: 8.4 (New Section)

Second Letter Ballot

Ballot Item 2

(New Section to be added to Chapter 8)

8.4 ELEVATOR DESIGN REQUIREMENTS

8.4.1 REFERENCE DOCUMENT

The design and construction of elevators and components shall conform to the

requirements of ANSI A17.1, American National Standard Safety Code for

Elevators, Dumbwaiters, Escalators and Moving Walks, and the Proposed A17

Seismic Regulations, except as modified by provisions of this chapter.

8.4.2 ELEVATOR AND HOISTWAY STRUCTURAL SYSTEM

Elevators and hoistway structural systems shall be designed to resist

seismic forces in accordance with formula 8-1 and Table 8-B.

W is defined as follows:

Element

Traction Car C + .4L

Counterweight w

Hydraulic C + .4L + . 25P

C is weight of car

L is rated capacity

W is weight of counterweight

? is weight of plunger

8.4.3

ELEVATOR MACHINERY AND CONTROLLER ANCHORAGE(S)

Elevator machinery* and controller anchorages shall be designed to resist

seismic forces in accordance with formula 8-2 and Table 8-C

.
8/6 continued

BALLOT ITEM 2 CONTINUED

8.4.4

SEISMIC CONTROLS

All elevators with a speed of 150 fpm or greater shall be furnished jwith

signaling devices as follows:

(a) A seismic switch device to provide an electical alert or command

for the safe automatic emergency operation of the elevator system.

fl (b) A counter weight displacement or derailment device to detect

lateral motion of the counterweight.

a-i

A continuous signal from (£) or a combination of signals from (a) and

(b) will initiate automatic emergency shutdown of the elevator system.

8.4.5 RETAINER PLATES

Retainer plates are required top and bottom of the car and counterweight

except where safety stopping devices are provided. The depth of engagement

with the rail shall not be less than the side running face of the rail.

8.4.6 DEFLECTION CRITERIA

The maximum deflection of guide rails, including supports, shall be limited

to prevent total disengagement of the guiding members of retainer plates

from the guide rails' contact surface. -

FINAL BALLOT: YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

Because

cost impact,

to "Elevator

the existing

designing to

of the significance of elevator performance and potential

it was decided that a new section should be developed specific

Design Requirements." The material has been developed so that

formulas and proposed seismic coefficients can be used in

resist seismic forces.

A 23?
JOINT BALLOT NUMBER 8/7

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS PROPOSED CHANGE

TECHNICAL COMMITTEE: *8 ARCHITECTURAL COMMITTEE ITEM NUMBER: 2/3

MECHANICAL & ELECTRICAL

AXC-3-06 SECTION REFERNCE : TABLE 8-B

Second Letter Ballot

Ballot Item 3

X. Change entry under Partitions - "Elevators and Shafts" to Elevator Shafts.

(Editorial)

2. Add the following new entry:

Architectural Components

C

c Factor

Elevator and Hoistway Structural Systems

- Structural frame providing the 1.25

supports for guide rail brackets

- Guiderails and brackets 1.25

III II I

S G G

S G G

- Car and counterweight guiding 1.25 5 G G

members

FINAL BALLOT: YES

NO

ABSTAIN

DID NOT VOTE

COMMENTS ON PROPOSED CHANGE:

These new entries to Table 8-B allow general usage of equation 8-1.
JOINT BALLOT NUMBER 3/8

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS PROPOSED CHANGE

TECHNICAL COMMITTEE : //8 ARCHITECTURAL COMMITTEE ITEM NUMBER: 2/4

MECHANICAL & ELECTRICAL

ATC-3-06 SECTION REFERENCE : TABLE 8-C

Second Letter Ballot

Ballot Item 4

1. Add the following new entry:

, C

c Mechanical/Electrical Components Factor III II I

Elevator Machinery and Controller 1.25 5 G

Anchorage

FINAL BALLOT: YES

NO

ABSTAIN

DID NOT VOTE

COMMENT ON PROPOSED CHANGE:

This new entry to Table 8-C allows the general usage of equation 8-2.

A 2 3 4
I

I

COMMITTEE 9

o

. A2 3 5
JOINT

BALLOT

NUMBER 2.0 Committee Actions

2.1 Recommended Changes

The following is a compilation of the results of the Committee 9 ba'ilot

issued on April 14, 1980.

Section

Af f irma tive

with

Affirmative Negative Reservations

Did Not

Voce

9/1

9/2

Chapter 1 - Change of title 6 votes 2 votes' 7^

-Ofor Chapter 1 from "Administration" to "General

Provisions

Section 13.1.1 - Change the 7 votes -0- 1 voce"

word "designed" to "with a permit issuance date" in

paragraphs one and two of

Section 13.1.1.

Summary of "Remarks" offered on negative and affirmative with reservations

ballots

^ "The chapter should be titled ’General’. This document is not a code - 'General Provisions' is code language".

2 / n ' "Propose 'Application'".

7 '/ "With regard to seismicity index of 4, Add asterisk and Note:

Local jurisdiction may change this for their location".

2.2 Recommendations for Trial Designs

1. The committee recommends that economic studies be undertaken in conjunction

with the trial designs to determine the economic impact of the provisions

on one- and two-family dwellings in all Seismicity Zones.

2. It was recommended that the seismicity index numbers appear on the map

legends to correspond to the designated map areas.

3. Chapter 13 should be re-written so that it can be comprehended by the

layman. As presented in its current version, the chapter is difficult

to understand and comprehend.

4. Chapter 13 should be reviewed for its applicability to the Eastern part

of the United States. R„ of 1 is for all practical purposes not attainable for most older buildings in the Eastern part of the U.S.
1R

COORDINATING COMMITTEE
Review and Refinement of Tentative Seismic Provisions

Proposed Changes

Coordinating Committee

Joint

Ballot

Number

S/1

S/2

S/3

S/4

S/5

I

Item

Table 1-B:

4 to 3

.

Table 1-B:

3 to 2

.

Table 1-B:

2 to 1.

Table 1-B:

2 to 1

Table 1-B:

1 to 0

.

change the Seismicity Index for Map Area 5 fro

change the Seismicity Index for Map Area - fro

change the Seismicity Index for Map Area 3 fr:

change the Seismicity Index for Map Area 2 fro

change the Seismicity Index for Map Area 1 fro

Comment :

Several of the technical committees balloted various changes of the seismic

index. Because of the intense interest, the Coordinating Committee decided

to pull all these items together for the Joint Committee ballot.

A238
Review and Refinement of Tentative Seismic Provisions

Proposed Changes

Coordinating Committee

Joint

Ballot

Number

S/6

S/7

S/8

Item

Revise Joint ballot number 3/4, as follows:

At the end of paragraph 2 of Section 7.4.4 (before Item A)

the following sentence should be added, "Where special

reinforcement at the top of the pile is required, alternative

measures for containing concrete and maintaining ductility

at the top of the pile will be permitted provided due

considerat ion is given to forcing the hinge to occur in

the contained section."

Revise joint ballot number 4/5 as follows:

Add the following sentence at the end of paragraph

"Pile cap connection may be by means of developing

pile reinforcing strand if a ductile connection is

Add the following sentence to the end of section 7.5.3(C):

’Pile cap connection shall not be made by developing exposed

strand ."

7 . 4 . 4 1 E j : exposed

provided .

Comment :

These revised ballot items resolve conflicts between changes proposed by

Committees 3 and 4.

A 2 3 9
1I
UNITED STATES DEPARTMENT OF COMMERCE

National Bureau of Standards

Washington, D.C. 2Q234

July 18, 1980

MEMORANDUM TO: Participants in the Review and Refinement of the Tentative

Dear Participant,

For those who did not attend the meeting on July 16-17 at NBS, a copy of

the proposals for change is enclosed, along with a ballot to be returned

to NBS, postmarked no later than July 31, 1980. An addressed and franked

envelope is enclosed for your use. Please note: if you were represented

at the meeting by a proxy, this material was given to your proxy.

For all participants , some additional information is enclosed as follows:

a statement from Committee 4 concerning ballot item 4/12

(four pages)

a statement from Committee 8 concerning ballot item 8/6

ATC comment on ballot item 4/12 (two pages)

ATC presentation on Committee 1 by Neville Donovan (three pages)

information summarizing the actions of various Committees on proposals that are the same, or similar to, ballot items

proposed by different committees. These items are 4/3, 4/6,

4/8, 4/9, and S/1 through S/5 (three pages).

In connection with the last item, please note ballot item 2/10 when you

consider ballot item 4/11.

All participants should note : the ballot items proposed by Committee 5

(5/1-13 and 5/A1-A37) should not be balloted at this time. The Committee

has subdivided their ballot, and they are preparing documentation for each

ballot item. This is with intent of facilitating your balloting of their

proposals. The revised material and supplementary ballot will be sent to

you in one week and will be due one week after the basic ballot. This

supplementary ballot will also include proposals from Committee 4, but

you are requested to completely ballot Committee 4's proposals on the

basic ballot and then consider their supplementary proposals in an independent ballot.

Please note that the ballot is a "YES/NO" ballot. This does not mean

that you may not comment. You are encouraged to send comments along

with your ballot. They will be summarized for the BSSC.

If you have any questions regarding these items, please call

Dr. J. R. Harris at (301) 921-2170.

Sincerely

,

Seismic Provisions

Joint Committee on Review and Refinement

B-l
e foso JUL 1

COMMITTEE 4 - CONCRETE

BALLOT ISSUE 4/12 REPORT

1. Committee 4 met four times. From the second meeting onwards the major

issue became a proposal to adopt the latest proposed revision to ACI 318

Appendix A in place of the existing Chapter 11 of ATC 3-06. Initially, the

Committee was reluctant to take that step because of anticipated difficulties

in integrating Appendix A with the remainder of ATC 3-06 and with other

proposals developed by the Committee for revisions to the existing Chapter 11

of ATC 3-06. However, through the dedicated effort of several Committee

members, and particularly the PCA representative, a comprehensive proposal,

ballot item 4/12, was developed that:

(a) provides a substitute Chapter 11 incorporating the 19 March 1980

proposed revision to Appendix A of ACI 318-77,

(b) contains provisions that interface Appendix A with the remainder

of ATC 3-06 while simultaneously incorporating other proposals

accepted by the Committee as desirable revisions to the existing

Chapter 11, and

(c) identifies the changes necessary elsewhere in ATC 3-06 for

incorporation of the substitute Chapter 11.

2. In its deliberations the Committee made an in-depth review of Chapter 11,

compared its design provisions with those of the proposed revision to

Appendix A of ACI 318-77 and realized that numerous changes would be

necessary to upgrade existing Chapter 11 to the latest ACI criteria. Thus,

the majority of Committee 4 is recommending the adoption of the new ACI

provisions, considering this to be the most efficient approach and in the

best national interest for trial designs.

Therefore, with respect to Chapter 11, Committee 4 is recommending

in ballot issue 4/12 that the nationally accepted design standard ACI 318-77

"Building Code Requirements for Reinforced Concrete," including proposed

revision - Appendix A "Requirements for Reinforced Concrete Building

Structures Resisting Forces Induced by Earthquake Motions," dated 19 March 1980,

be adopted by reference into ATC 3-06 for proportioning and detailing concrete

structures. Revised Appendix A is now before the full ACI Building Code

Committee 318. Final Committee action and full ACI consensus balloting is

forthcoming.

3. The vote on ballot issue 4/12 by Committee 4 was 7 in favor and

1 opposed.

4. The reasons advanced by the majority of the Committee for accepting

issue 4/12 are:

(a) Adoption of the total ACI 318 Standard is appropriate because

seismic resistance is considered in the overall development

of the 318 Standard, including Appendix A on special provisions

for earthquake resistance.

B-2
2

(b) Existing ATC 3 Chapter 11 originated from an early draft of a proposal by an ACI 318 Seismic Subcommittee to update the ACI 318

seismic design provisions. The basis of existing Chapter 11 was

work developed under the guidance of Dr. Mete Sozen who served on

the original ATC Concrete Task Group. Dr. Sozen is current

Chairman of the ACI 318 Seismic Subcommittee which has the prime

responsibility for the new proposed Appendix A of ACI 318. The)

ACI 318 Seismic Subcommittee worked towards producing a document

that would be acceptable to the two professional communities

involved—ACI and SEAOC. .Two members of SEAOC, Clarkson Pinkham

and Loring Wyllie serve on the 318 Seismic Subcommittee to

provide SEAOC and ATC technical perspectives to ACI 318.

(c) The ACI 318 Standard is prepared and continuously updated in

accordance with a rigorous consensus procedure approved by the

American National Standards Institute and designated as ANSI/ACI

318-77 (A89.1). The ACI 318 Standard is unique among material

design specifications in this regard. Because of the extensive

review and adoption procedure, ACI 318 represents the state-ofknowledge for reinforced concrete and is widely adopted by model

building code groups to regulate concrete design ^and construction.

(d) Membership of the ACI Building Code Committee has a wide geographical

representation, with input from design professionals (including

prominent engineers from earthquake-prone areas), educators,

researchers, material and construction industries, government

agencies, and building officials. The consensus procedure under

which the document is prepared draws from the best documented

data available.

5. The SEAOC representative on Committee 4, Mr. Wyllie, opposes issue

4/12 because he questions the wisdom of adopting for trial design a new

set of provisions (Appendix A) that are incomplete in certain details,

have not been thoroughly reviewed and adopted by Committee 318 of ACI,

and are unaccompanied by detailed technical justification. He also

believes the proposed change is a technical weakening of the existing

Chapter 11 provisions.

Mr. Wyllie did, however, join with the majority of Committee 4 in

unanimously adopting the following resolution: "Regardless of subsequent

actions, it is the firm intent of Committee 4 that the final version of

ACI 318 Appendix A, with appropriate modifications, be incorporated into

ATC 3-06 aftr trial design."

6. The ATC representative. Dr. Bertero, did an outstanding job of working

with the Committee and assisting it in developing desirable revisions to

the existing Chapter 11. However, from the beginning he adamantly opposed

substituting the proposed revision to ACI 318 Appendix A for the existing

Chapter 11 contending that such an action was not within the scope of the

Committee's mission. Dr. Bertero did not attend- the last meeting of the

Committee at which issue 4/12 was finalized and letter balloted. Instead

B-3
3

he sent in a letter of resignation from the Committee, accompanied by

six pages of detailed comments on the proposed Chapter 11, the changes

necessary to integrate it into the remainder of ATC 3-06, and the changes

desirable in Appendix A. He concluded that:

THE UPDATED DRAFT OF CHAPTER 11 SUBMITTED BY FINTEL ON MAY 29, 1980

AS SUGGESTED BY THE INDUSTRIES, CANNOT BE ACCEPTED FOR INCORPORATION

TOGETHER WITH A NEW APPENDIX A INTO THE ATC 3-06 .

Even if new drafts of this chapter and Appendix A, including all

the corrections, additions and clarifications suggested in the

attached comments, are prepared, it would be a mistake to introduce

them into ATC 3-06 for the TRIAL DESIGN PHASE . The main reason is

that the designers will have to consider two new and very confusing

cross references (Chapter 11 and the new Appendix A) which would

increase the probability of misinterpreting the provisions. Even

if designers are able to interpret correctly the interfacing provisions of the new Chapter 11 and Appendix A, no significant

technical improvement in the design will be obtained.

Dr. Bertero did, however, agree that Chapter 11 of ATC 3-06 needed to be

updated and integrated with the new Appendix A. He recommended that:

A TECHNICAL SUBCOMMITTEE, WITH MEMBERS FROM COMMITTEE 4 AND THE

ACI COMMITTEE THAT HAS PREPARED THE NEW APPENDIX A, BE FORMED

AND CHARGED WITH THE MISSION OF IMPROVING AND INTEGRATING THE

NEW APPENDIX A INTO CHAPTER 11 OF ATC 3-06.

7. At their final meeting, the majority of Committee 4 disagreed with

Dr. Bertero' s conclusion. They feel that significant technical improvements in design will be obtained by using the recommended Chapter 11,

including Appendix A, as compared to the existing Chapter 11. Examples

of technical improvements in Appendix A are the simpler rules for anchorage

of bars, more realistic rules for the design of joints of frames and

recognition that the strong column-weak beam frame is not always practical

and a strong beam-weak column frame is sometimes necessary. In addition,

in the sections of the recommended Chapter 11 providing transition from

the existing ATC 3-06 to Appendix A there are important new concepts,

approved by Dr. Bertero and Mr. Wvllie, and covering:

(1) the use of flat plate framing systems for buildings assigned

to category B,

(2) precast and/or prestressed concrete framing systems for

categories B, C and D, and

(3) the use of precast floors as structural diaphragms.

B-4
4

Failure to utilize the best available state-of-knowledge for trial designs

would not be in the national interest. Given the nature of the differences

between the existing Chapter 11 and the proposed Chapter 11, incorporating

Appendix A, the costs of designs that provide adequate seismic resistance

for large portions of the country would be considerably greater for the

existing than proposed Chapter 11. Action approving ballot issue 4/12 supersedes

actions on issues 4/13 through 4/19.

July 18, 1980
Comment

From: Robert N. Sockwell, AIA

Chairperson: Committee 8, Architectural, Mechanical and Electrical

Re: Clarification of Ballot Item 8/6

Section: 8.4, Elevator Design Requirements

Sub. Sec: 8.4.1, Reference Documents

This is a response to questions raised by members of the Joint Committee

concerning the appropriateness of the wording of 8.4.1. Although it may

appear that ANSI A17.1 (ANSI Safety Code for Elevators) is being selected

as the singular acceptable design standard for elevators, that was not our intent. The committee considered A17.1 to be the most up-to-date and

appropriate standard to reference for the seismic design of elevator systems.

We intend to reword 8.4.1 to clarify its intent before ATC-3 becomes a final document.

I feel that the present wording of 8/6 will not impact the trial design

phase, and ask that you vote affirmative on this issue.

B-6
7

r//Q>/8o

ATC POSITION REGARDING CHANGES TO CHAPTER 11

OF ATC-3-06 AS PROPOSED BY TECHNICAL

COMMITTEE 4, CONCRETE

Technical Committee 4 proposes that a draft of Appendix A, ACI

Standard 318-77 be substituted for Chapter 11 of ATC-3-06. ATC strongly

opposes the proposed change for the following reasons:

1. The objective of the NBS Work Plan for Review and Refinement

of Tentative Seismic Provisions is to review and refine the

ATC-3-06 provisions so that they will be suitable for conduct

of comparative trial designs. As stated in the Work Plan:

" It is important to realize that this activity is neither the

development of a draft standard nor the affirmation of a standard, only a mid-course adjustment thought necessary for

wise expenditure of research funds for the conduct of trial

designs. 11

The purpose of the trial designs is to help make an assessment

of new concepts and new requirements embodied in the Tentative

Provisions. The proposed substitution of a draft document for

Chapter 11 does not fall within the objectives or scope of the

NBS Work Plan. 77to. /fop&nc'i vt A cb&f

2. In carrying out the review and refinement it has been agreed

that changes to the provisions should not be made just for the

sake of changing or because a particular provision(s) is not'

liked. Rather changes are to be made to clarify the intent of

a provision or to make a technical correction. There is no technical justification for making the proposed substitutions

noi- cjajri '/y l 74»W\

Sa o fi 3. Abe draft Appendix A provisions are less restrictive than

those in Chapter 11. No^justifi cation has been presented for

reducing the Chapter 11 requirements.

7Le-cAntcaJl / iv~/3rot/e. #5 S&timiC desert a/? C-ancjr&Ae. bu*uc£y*ufs d

C<r-r\ c e- r-n e<s4

B-7
4.

/^C / Com/m 3/3 dnc/

The proposed Appendix A substitution is still a draft because

it has not been accepted by/the ACI membership. Therefore it

is not a "consensus" document. Therefore, if the proposed

substitution is made, the trial designs would be conducted

using provisions that are still to be finalized.

5. The proposed substitution is premature. After ACI 318-77,

Appendix A is adopted by the ACI membership and thus becomes a "consensus" document, the question of substituting its

provisions for those in Chapter 11, ATC-3-06 can be addressed.

C>. Thg. C^ryyinn^n.-/- J^as bee^, -3 7/ /S

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B-8
Notes of presentation to ATC-3-06 Review / 7

-7

-^y- AJg.J- <3£-?S^ti c 5

NBS July 16, 1980

~ ~ ' “TM '

I appreciate the opportunity of addressing the assembled members of the different project committees and all of the parties interested in seismic design

improvements

.

In responding to the committee decisions and the results of their vote it

should be pointed out that the committee only met once. This was at the organizational session here at NBS last December. It may be presumptuous but

if we had met I believe I could have at least tempered some of the decisions.

The ATC-3 document was the result of many compromise decisions and if neither

the need for compromise nor the results of this compromise are recommended by

all committees then the current NBS effort will ultimately be non-productive. The

primary aim of the review of the ATC-3-06 provisions is to enable trial designs to proceed more efficiently. As the actions of Committee 1 are primarily related to seismic zoning they do not have any influence of the trial designs. However, the committee has raised several issues and voted on them

so as a major ATC-3 participant they should be responded to.

The major thrust of actions presented to the committee for consideration were

suggestions, possibly by those with vested interests, for lowering the criteria. The only unanimity appears to be for less. The committee voted not

to approve the suggested change in the Seismic Performance Category Table,

Table 1-A and voted against most of the changes suggested for Table 1-B

except those relating to areas of lower seismicity (Map Areas 1 and 2). In

this regard, a misconception was circulated that the seismicity in zone 1 was

zero and that the effective peak acceleration values in Map Area 2 are actually less than 0.05g. The contours are given in Appendix Cl-3 and all areas

B-9
in Map 2 lie within a contour value of 0.05g or greater. The misconception

regarding areas of zero seismicity was one that our ATC-3 Task Group battled

with even to the point of unsuccessfully recommending that the number sequence

of the map areas be reversed so that zero was not even available. From purely

seismological terms there is no state among the 50 in the Union in which earthquakes have not been recorded. Low seismicity we can agree with but not zero

seismicity

.

Two additional changes apart from alterations to the Tables on page 35 of

ATC-3-06 were made and voted upon. The first of these was to base the zoning

map directly on contours rather than the present county-by-county procedure.

This same recommendation was made to the full ATC-3 group when the maps were

first developed but despite diligent effort they were not accepted. The primary reasons are procedural. Contours would have to be extended outside the

United States and closed to allow interpolation to be performed in border

areas. Some forms of construction are only permitted below certain design

levels. These zonations are not distinct when contours are used. The ATC-3-06

report recognized the difficulties with a county-by-county basis and on page 29

of the recommended procedures gave an alternate version which does not require

any direct application of a map. Human nature being what it is, and as has

been demonstrated by this present review, effort will be spent lobbying for

lower, not higher numbers so if ATC-3 were adopted the alternate procedure

could be invoked to reduce discrepancies.

The second request was to include in the guidelines a definition of an active

fault. I am inalterably apposed to this suggestion. The question of what

constitutes an active fault is not one upon which there is broad professional

B-10
agreement so it should not be "defined" within a code. The suggested definition is inadequate for another fundamental reason,

frequency of movement and the amount of movement are

which may move by an inch or two is certainly not as

may move several feet.

Thank you for your attention.

Consideration of the

not considered. A fault

hazardous as one which

AJ&//L.L£ /fT^
Ballot item 4/3 : Committee considered a similar proposal to change the vertical

toad requirement {on horizontal pn.e4tn.ei> ted members. The minutes o{ that discs

'•'Is cusston follow:

Section 3.7.12 , Vertical Seismic Motions: The proposed modification submitted

by Professor Hawkins through committee 4 was considered. Harris questioned

whether the proposed really stated what Hawkins really meant. Holmes

speculated that the intent was to apply an upward seismic force of 0.2Q^,

not an upward net force of 0.2Q^. Iyengar pointed out that the stated

reason did not correspond to the recommended change. The proposal was tabled and Fintel was charged with contacing Hawkins prior to the Thursday

session. Fintel was unable to contact Hawkins, and the proposal received

no further consideration.

Ballot Itm 4/6: Committee 3 considered a very similar proposal, l.e. to make

the Category V requirements faor piles the same <xi f\or Category C. Their actr^~ :

lid Discussion

The committee considered the comments that were received, but decided

that additional conservatism was required for Category D structures.

Therefore, Section 7.6.1 should not be modified.

lie Recommendat ion

The committee recommended not to change or delete Section 7.6.1

B-12
Ballot itern^ 4/8 and 4/9.: Committee contldeAed the. &ame pAopot>aJU>. This Aheet

AummaAlze* thelA action. flA6t, the. original text o{) the. pAoposalt,

:

SEC. 8.2.3 Add the following sentence at the end of this section.

"Connector fasteners shall develop elastic forces

resulting from twice the loads determined- from

Section 8.2.2 above."

SEC. 8.2.2

BASIS : Current practice as outlined in UBC-79.

Add the following sentence at the end of this section:

"The force Fp shall be applied in the vertical direcion, as well as longitudinally and laterally, in

ombination with the static load of the element. ti

co

BASIS: UBC-79; The effect of vertical acceleration

should be included in design of non-structural components and systems.

Ex.zeA.pt ^Aom the AetponAe to the pAopotal by the ATC AepAe^entatlve oa Committee 8

. Section 8.2.2 FORCES

I disagree with this comment. The Fp , on parts of structures, is normally

considered as a horizontal force, from any direction.

. Section 8.2.3 EXTERIOR WALL PANEL ATTACHMENT

I disagree with this comment. C^ value for wall attachment is already

high and beyond this, detailing ductility is the important requirement.

- ztlon taken by Committee 8:

Issue 1 Section 8.2.3 Exterior Wall Panel Attachment

A motion was made by Swatta, seconded by Wintz that the ATC recommendation

for no changes be accepted. Motion passed 5-0.

Issue 2 Section 8.2.2 Forces

Mo tion made by Swatta and seconded by Wintz, passed 5-0, to accept ATC

recommendation for no changes. The argument was nonpersuasive as no specific

reference was given for UBC-79 practice.

B-13
BALLOT ITEMS S/1 thn.oo.gh S/5: Committee^c.onAi.deAed each o{) thebe pnopobaLb . The

ioltoDJlng i'hom thz nzsuJLU of, thztn baLtot and li ZKC.zn.ptzd iym thz mtnatzi

theJji thijid meeting. Item 2 beZou) conAebponcU to baLtot item S. 1 , -item 3 eowie

6pond6 to baLtot item S/2, etc.:

jji

Ballot I tern Initial

yes

Tally*

no Final

yes

Tally*

no Remarks

Following

1. S. Perf. Category 5 3 0 8 a

2. s. Index, Area 5 3 5 2 6 a

3. s. Index, Area 4 2 6 2 6 a

4. s. Index, Area 3 2 6 2 6 a

5. s. Index, Area 2 4 4 2 6 a

6. s. Index, Area 1 2 5 0 7 a

Notes on the ballot items:

a. Harris pointed out that further consideration of the discussion

in Phoenix convinced him that item 1 should have been contingent

on item 6 alone. The committee agreed. None of the changes

proposed for the seismicity index carried on the initial tally,

and the sentiment of the committee shifted somewhat towards

recommending no change for the purpose of trial design. Iyengar

felt that item 5, changing the seismicity index for map area 2 from a 2 to a 1 was quite important; he felt that many locations

in that map area would unilaterally decide to ignore seismic

provisions such as those included for seismicity index 2.

B-14
UNITED STATES DEPARTMENT OF COMMERCE

National Bureau of Standards

Washington, D C, 20234

July 24, 1980

MEMORANDUM TO: Participants in the Review and Refinement of the

Tentative Seismic Provisions

Dear Participant:

This package allows you to complete balloting the proposed refinements to

the ATC- 3-06 provisions. Recall that Committee 5 (Masonry) has reformated

their ballot items and documented each proposed change so that your task

of completing the ballot will be easier. Also recall that Committee 4

(Concrete) has proposed seven supplementary ballot items for proposed

changes in Chapter 11 of ATC-3-06. These supplementary items each passed

Committee 4 but were not included in the joint ballot because they were

supplanted by joint ballot item 4/12 (the direct reference to Appendix A

of ACI 318). You are requested to ballot on these supplementary items

with the understanding that they will be counted only if item 4/12 does

not pass.

Attached to this letter are:

- A summary of the actions of Committee 5 (Masonry), written by

the secretary of the committee.

- A general comment from ATC on the Committee 5 ballot.

- A comment from ATC on the supplementary items from Committee 4 (Concrete).

Enclosed in this package are:

- Two ballot tally sheets, one to be returned to NBS in the attached

return envelope.

- The supplementary ballot items from Committee 4.

- The version of Chapter 12 marked with Committee 5's ballot items 5/1

through 5/28.

- A tabulation of the Committee 5 comments and the ATC comments on the

ballot items in Chapter 12.

- The version of Chapter 12A marked with Committee 5

? s ballot items

5A/1 through 5A/81.

- A tabulation of the Committee 5 comments and the ATC comments on the

ballot items in Chapter 12A.

Please complete and return this ballot as soon as possible. It must be postmarked

no later than August 8, 1980, to be counted. Once again, comments are welcome.

If you have any questions, please call Dr. J. R. Harris at (301) 921-2170.

Joint Cofomittee on Review and Refinement

Enclosures B-15
Record of Ballot History of Committee 5

The following is an abbreviated record of how Committee 5 arrived at the

enclosed ballot document.

• At the initial December II meeting of Committee 5, two

points were agreed upon by the Committee. These are:

1. It is invalid to use ultimate strength design

for masonry.

2. Chapter I2A is not an acceptable document for

masonry design in nonseismic areas.

• On January 4 a task group met in Northbrook, IL to further study

the points described in the December II meeting of Committee 5.

The task group made the major decision that they would rework

Chapters 12 and I2A even though that meant using the ultimate

strength concept. The task group had reservat ions, but they

did agree to move in that direction. At the task group meeting, it was still agreed that Chapter I2A, as it existed, was

not a workable document. The task group, however, was divided

into two equal groups that each wanted to go their own direction.

These two groups agreed to prepare proposals for the next

committee meeting.

• At the February 21 and 22 meeting, two presentations were

made to the committee with regard to Chapter I2A. One

proposal involved modifying AC I 531 on masonry design so that it would include both clay and concrete products and

substituting that for Chapter I2A. The second proposal

was presented by a group that had carefully examined

Chapter I2A and concluded that it was possible to modify

it for use in trial designs. That group proved its point

by presenting a detailed examination of Chapter I2A and

the needed revisions. After much discussion, Committee 5 agreed unanimously to proceed with the Droposal to moai^y

Chapter I2A.

• The committee next met in Denver on March 21 and 22. At

this meeting Chapter I2A was finished and Chapter 12 was examined in some detail and prepared for ballot. At the

conclusion of this meeting, both Chapters 12 and I2A were

in the committee’s hands for ballot.

It 'should be noted at this point that the committee discussed

all items in Chapters 12 and I2A at the Arlington, TX and

Denver, CO meetings to determine changes that should be

balloted in written form. Thus, prior to written ballot,

each item was voted on i n a committee meeting. The next

stage was to collect written ballots with written comments.

B-16
• The next meeting of the committee was held in Chicago on May 16. The committee held an 18 hour session in Chicago

and completed discussion and reballoting of all items of

Chapter I2A. At that point, the ATC representat i ve asked

that the committee set aside its prior ballots on Chapter 12

and give ATC the opportunity to prepare a new Chapter 12

which considered changes the committee had made in Chapter I2A.

The committee agreed to do this and set the next meeting

for Washington, DC to discuss the ATC proposals.

• The committee next met in Washington, DC on June 5 and 6.

Prior to taking up Chapter 12, the committee concluded its

discussions of Chapter I2A by i ncorporat i ng design guidelines for hollow clay masonry. The committee then took up

the ATC proposal for Chapter 12. The committee went through,

item by item, all proposals for Chapter 12 that were presented

by the ATC representat i ves to the committee.

• The enclosed ballot document indicates every item that was balloted in written form by the committee and the resulting

vote count. At the July 16 and 17 meeting of the full Joint

Committee, a ballot was presented and discussed in limited

detail by the committee and by the ATC representat i ve. At

that meeting, it was made clear by the attendees that the

ballot document that had been put together grouped too many

individual changes into each ballot item. The full Joint

Committee indicated that it would prefer to ballot on a larger set of items, each with a small number of changes,

so that the work of the committee could be considered -in more detail. Committee 5 then held an evening session on July 16 and a session on July 17 and reported back to the

Joint Committee that they could indeed provide the material

requested. The enclosed ballot document is the result of

the efforts of Committee 5 and the ATC representat i ves to

prepare the requested material.
APPLIED TECHNOLOGY COUNCIL'S COMMENTS

ON COMMITTEE 4 BALLOT ITEMS

ITEM 4/15: The new section 11.9 as worded would apply to all categories of

buildings, A through D, which would make the new section applicable to high

seismic risk areas. This is a sweeping change and is going too far too fast.

For applications in high seismic risk areas, such as California, these

provisions should be carefully reviewed and studied by professional

committees, such as the SEAOC Seismology Committee. ATC therefore strongly

recommends that the new section 11.9 not be adopted as written, but that

it be modified to apply only to category A and B buildings until more

study can be given. This recommendation has resulted from further consideration by the ATC representatives.

•

ITEM 4/19: The wording of the proposed addition to the commentary should be

modified as follows to make it clearer: in the second line change "will"

to "should," and in the third line, insert "are" before "greater." The

reason for changing "will" to "should" is that the drift limits of

Table 3-C would be changed if ballot item 2/22 is adopted. ATC concurs

with the proposed addition to the commentary as modified above.
APPLIED TECHNOLOGY COUNCIL'S COMMENTS

ON COMMITTEE 5 BALLOT ITEMS

INTRODUCTION

Chapter 12A was included in the ATC-3-06 report because a nationally

applicable design standard for masonry was and is still not available.

Thus Chapters 12 and 12A were developed as complementary documents. Some

seismic provisions were included in Chapter 12A and thus many of the

bollot items involve a transfer of these items to appropriate Sections of

Chapter 12.

Many of the other ballot items involve minor and editorial changes

and ATC concurs with most of these. However, there are a number of other

ballot items that ATC believes are substantive changes to the document.

Comments on these items are in the accompanying tabulation of comments.

There are two important items that have not received 'adequate consideration by the committee at this time. These are the allowable stresses

for unreinforced masonry and the design requirements for hollow unit masonry.

ATC therefore strongly recommends that Committee 5 continues its

deliberations beyond the meeting of July 16th and 17th. This will ensure

that consistency, cross-referencing and definitions have been adequately

covered as a result of the large number of changes and that the two items

referred to above can be adequately addressed.

B-19

APPENDIX C

NEW PROPOSALS RECEIVED

AT THE FINAL MEETING

OF THE JOINT COMMITTEE

Two proposals for change to the Tentative Provisions were received by the

Joint Committee at their final meeting on July 16-17, 1980. They are:

1. "Proposed Revisions to Chapter 7 Foundations" submitted by

Frank M. Fuller of Raymond International Builders.

2. "Recommendations to Incorporate Provisions for the Eccentric

Braced Frame in ATC 3-06 Tentative Provisions for the Development

of Seismic Design for Buildings, June 1978," submitted by

William Smith of the American Iron and Steel Institute.

These two proposals are included in this appendix.

Because these proposals were not acted upon by any of the technical committees,

the Joint Committee did not ballot them. They are included here for future

consideration.

Proposed Revisions to Chapter 7 Foundations

ATC-3-06 Report

Submitted by

F. M. Fuller

Raymond International Builders Inc.

(1) Section 7.4.4 (A) UNCASED CONCRETE PILES: Revised to

read as follows:

(A) UNCASED CONCRETE PILES: Reinforcing steel

shall be provided for uncased cast-in-place concrete

piles, drilled piers or caissons with a minimum of

four No. 5 bars with a minimum steel ratio of 0.005

for pile diameters up to 24 inches and 0.0025 for

diameters of 24 inches or greater. Such steel shall

be enclosed in a steel spiral of minimum No. 2 bar

and a maximum 6-inch pitch except the maximum pitch

for the top two feet shall be 3 inches.

COMMENT: Seismic reinforcing should be full length

for concrete piles not enclosed in a steel casing.

If ground motions starts from below the pile tip,*

any unreinforced lower portion of the pile will

readily crack and may be displaced resulting in possible foundation failure.

The current requirements for minimum steel ratio in

the ATC Report were based on the assumption that uncased piles would be of relatively large diameter.

Inasmuch 'as the eventual seismic regulations will

apply nation wide, it must be recognized that uncased cast-in-place concrete piles are being installed

with conventional diameters comparable to metal cased

piles. Therefore, the minimum steel requirements

have been increased for piles less than 24 inches

in diameter.

The above revision permits only the use of a steel

spiral for lateral steel and specifies a minimum

bar diameter which is not in the current wording.

Also, the maximum pitch has been decreased for both

the body of the pile and the top two feet. The

main purpose of the spiral steel under seismic loading is to confine the core concrete and provide a measure of ductility to the pile. This acts to

some degree like the metal casing although it is

not as efficient or effective.

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Page 2 - Proposed Revision to Chapter 7 ATC-3-06 Report

The maximum 6 inch pitch is necessary to get a reasonable degree of confinment of the core concrete

The 6 inch spacing makes the use of a spiral much

more practical than individual hoops. Square ties

should not be permitted because they offer no

conf inment

.

(2) Section 7.4.4 (B) METAL CASED C 9NCRETE PILES: In the

last line change "3 inches" to "4 inches".

COMMENT: The steel casing provides full confinment

and therefore the 3-inch spacing is unnecessary.

(3) Section 7.5.3 (A) UNCASED CONCRETE PILES: Revise to

read as follows:

(A) UNCASED CONCRETE PILES. Reinforcing steel shall

be provided for uncased cast -in-p lace concrete piles

drilled piers or caissons with a minimum of four

No. 6 bars with a minimum steel ratio of 0.0075

for pile diameters up to 24 inches and 0.005 for

diameters of 24 inches or greater. Such steel shall

be enclosed in a steel spiral of minimum No. 3 bar

for pile diameters up to 24 inches and No. 4 bar for

piles of 24-inch diameter or greater. Spiral steel

shall have a maximum pitch of 6 inches except that

the maximum pitch for the top four feet shall be

3 inches.

COMMENT: The same basic comments as stated above

under Item 1 apply to this Item. The increase in

steel ratio for piles less than 24 inches in diamete

recognizes the use of small diameter uncased concret

pi les

.

(4) Section 7.5.3 (B) METAL CASED CONCRETE PILES: In the

last line change "3 inches” to "4 inches”.

COMMENT: See comment for Item 2 above.

C-2
American Iron and Steel Institute

lOOO 10TH OTREtfT, n. w. WASHINGTON. D. C. 20039

RECOMMENDATIONS TO INCORPORATE PROVISIONS FOR THE

ECCENTRIC BRACED FRAME IN ATC-3-06 TENTATIVE PROVISIONS

FOR THE DEVELOPMENT OF SEISMIC DESIGN FOR BUILDINGS, JUNE 1978

The very worthy, steel eccentric frame does not appear to be classifiable

anywhere under the systems described on page 52, This is unfortunate since

ATC-3-06 is purported to represent the state-of-the-art. It should also be

recognized that extensive analytical studies coupled with cyclic testing of

large-sized subassemblages was thoroughly reported on by the University of

California as far back as 1977. Several papers have since been published.

The system is presently being used in construction of hospitals, banks,

hotels and office buildings in areas of high seismicity.

The following recommendations are those presently being proposed for incorporation in the Recommended Lateral Force Requirements of the Structural

Engineers Association of California and the City of San Francisco Building

Code now undergoing updating.

Tabl e 3-B, Response Mod ification Coefficients, To accommodate the eccentric

braced frame, the following additional entries are recommended for Table 3-B:

TABLE 3-B

RESPONSE MODIFICATION COEFFICIENTS1

Type of Structural System

BEARING WALL SYSTEM: A structural system

with bearing walls providing support for

all, or major portions of, the vertical

loads

.

Seismic force resistance is provided

by shear walls or braced frames.

BUILDING FRAME SYSTEM: A structural system

with anessentially complete Space Frame

providing support for vertical loads.

Seismic force resistance is provided

by shear walls or braced frames.

Vertical Seismic Coefficients

Resisting System R

; C ^

Light f ram ? d wa ] Is

with shear panels 6% 4

Shear v/all s Reinforced cone re t'.e 4

Reinforced masonry 3

Braced frames 4 3^2 Unreinforced and

partially reinforced masonry

shear walls0 lk Ik

Light framed walls

with shear panels 1 4'i Shear walls

Reinforced concrete 5% 5 Reinforced masonry 44 4

Braced frames 5 4 %
ATC-3-06 - Eccentric Braced Frames Page 2

Vertical Seismic Coefficients

Type of Structural System Resisting System R

7 C^ '

BUILDING FRAME SYSTEM (con't) Eccentric braced

frames designed

in accordance with

the provisions in

Section 10,7, 6 5

MOMENT RESISTING FRAME SYSTEM: A structural system with an essentially complete

Space Frame providing support for vertical

loads ,Seismic force resistance is provided

by Ordinary or Special Moment Frames capable of resisting the total prescribed

forces o DUAL SYSTEM: A structural system with an essentially complete Space Frame providing

support for vertical loads,

A Special Moment Frame shall be provided which shall be capable of resisting

at least 25 percent of the prescribed seismic forces. The total seismic force resistance is provided by the combination of the

Special Moment Frame and shear walls or braced frames in proportion to their relative rigidities.

INVERTED PENDULUM STRUCTURES. Structures Special Moment Frames

wh ere the framing resisting the total Structural steel" 0 ^ prescribed seismic forces acts essentially Reinforced concrete4

2-h as isolated cantilevers and

port for vertical load.

provides sup- Ordinary Moment Frai

Structural steel“

ns

, i n

^These values are based on best judgement and data available at time of writing

and need to be reviewed periodically,

“As defined in Sec. 10.4,1,

As defined m Sec. 10,6,

4 As defined in Sec. 11,7,

5 As defined in Sec, 11,4.1,

^Unreinforcea masonry is not permitted for portions of buiodings assigned to

Category B, Unreinforced or partially reinforced masonry is not permitted

_for buildings assigned to Categories C and D; see Chapter 12,

'Coefficient for use in Formula 4-2, 4-3, and 5-3.

Coefficient for use in Formula 4-9,

Shear walls

Reinforced concrete 8 6%

Reinforced masonry 6^

Wood sheathed shear

panel s S 5 Braced frames . 6

Eccentric braced

frames designed w-. accor da nce wi th th e prow' s i onsspe

c

i Tie d

in Secti n 10.7 8

Special moment

Frames

Steel 3 8 5h

Reinforced concrete4

7 6

Ordinary moment frames

Steel 2 4% 4

Reinforced concrete' 2 2

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ATC-3-06 - Eccentric Braced Frames Page 3

Add the following change to Section 3.3.4(A), which sets forth the types of

framing systems that may be used:

3.3.4 SEISMIC PERFORMANCE CATEGORY C

Buildings assigned to Category C shall conform to the framing system

requirements for Category B and to the additional requirements and limitations

of this Section.

(A) SEISMIC RESISTING SYSTEMS. Seismic resisting systems in buildings

over 160 feet in height shall be one of the following:

1. Moment resisting frame system with Special Moment Frames.

2. A Dual System.

3. A system with structural steel or cast-in-place concrete braced

frames or shear walls in which there are braced frames or walls so arranged

that braced frames or walls in any plane resist no more than 33 percent of

the seismic design force including torsional effects; this system is limited

to buildings not over 240 feet in height.

4. A buildi n g frame system in which the seismic design lateral,

fo rce including torsional effects is resi sted by eccentric braced fr ames.

Add a new Section 10.7 to provide design criteria for the eccentric braced

frame referenced in Table 3-B.

10.7 STEEL ECCENTRIC BRACED FRAMES

Eccen tri c braced frames shall be de signed in accordance with all

the provisions of Section 1 0.6, in addition to the re q uirements which fo 11 ow

:

1. Definitions.

in shear.

LlNK BEiAM is that part of the beam which is dcs i gned to yield

2. Design Criteria.

a) The link beam should be des igned to yield in shear at

a force not less than that obtained from an elastic, analy si s of the frame.

using the laterial forc es as prescribed by these provisions . The s hear

yield shall occur prior to b ending y leld. The link beam web shoe i -i b a a single thickness, without doublers.

b ) Ecc ent

r

ic Br a ced Frames u t llizing bending yielding of the

link beam may utilize the "R" values as described in Table 3-B if energy

absorption and due tilitv equiva 1 en t_ to that obta i ae d from the shear vi e i ding

systems cart be demonstrat ed. Othe rwise they shall be assigned "R" values the same as concentric braced frames.

C-5
ATC-3-06 - Eccentric Braced Frames Page 4

c ) Brace membe rs shall be designed for at least 1.5 times

the axi al forces and moments which occur at onset of link beam yieldin g

,

d) C o lumns shall be design ed using the "strong column. - weak

bean" concept, with the beam plastic moment capacity limited to a reduced

consistent with tha t allowed by the yielded web.

e) All of the requirements of Part 2 of Ref. 10,1 (Plasti c Design) shall be adherred to. Particular attention should be given to lateral

bracing of the beams and to the d/ t ratio of the link beam web. The need f or

v?eb stiffeners in the link beam web shall be considered. A lateral brace must

be placed at the. point of intersection of the eccentric brace with the beam

unless adequate bracing by some other svs tern can he properly substantiated.

f ) Ax ial forces, when occ u rring in th e link b eam., shall b e considered in the. design.

g) Ap propriat e cons iderati o n shou ld be given to the ccl lapse

mechanism for extreme loading conditions.

h) B eam to c olumn c onnectio ns shall d evelop the full r> 1 a s t i.

c

moment capacity of the hern an d the, full sh nr yield capacity of the web

.

Column flange and web stif feners should '

. e sinned according to the usual

me tiled s .

chosen. Pr

i) Brace to beam connections will depend on the brace sect;

imary requirements are than a pair of stiffener:; be orov : and in

the occa at the si.de of the connection. Ref ini i.g the end of the 1 ink bee.:., ?•; that brace force; transferred direc :.y to these stiffeners bv a f l:.'..?e (either a 1 Mange . the brace or the flange f a tee-shaped gusset). In no case should : uv com- on sent of the connection end into the link beam cone. The connect: ica shoal d be designed with the ad nitional factor of safety reThe foregoing recommended additions to ATC-3-C6 are based

now being considered by the Seismology Committee of the S

Association of California. Every effort has been made to

conform in all respects to those recommendations

on the recommendations

tructur.il Engineers

make these additions

Committee on Construction Codes and Standards

AMERICAN IRON AND STEEL INSTITUTE

July 11, 1980

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REFERENCES ON THE ECCENTRIC BRACED FRAME

C 0 W. Roeder and E. P. Popov. "Inelastic Behavior of Eccentrically braced

Steel Frames Under Cyclic Loading," EERC Report 77-18 , University of

California, Berkeley, August 1977.

C. W. Roeder„ "inelastic Behavior of Eccentrically Braced Frames Under

Cyclic Loadings," Ph.D. Thesis, University of California, Berkeley,

1977

.

C. W. Roeder and E. P. Popov. "Eccentrically Braced Steel Frames for Earthquakes," ASCE Fall Convention Preprint 2924 , San Francisco, CA,

October 17-21, 1977.

C. W. Roeder and E. P. Popov. "Eccentrically Braced Steel Frames for Earthquakes," Journal of the Structural Division , ASCE, Vol . 104, No. ST3,

March 1978.

Ashok K. Jain, Subhash C. Goel, Robert D* Hanson, Discussion of "Eccentrically Braced Steel Frames for Ear thquakes , " Journal o f the Structural

Pi vis ion, ASCE, Vol* 104, No. ST3, March 1978.

E. P. Popov and C. W. Roeder. "Design of Eccentrially Braced Frames,'.'

Engineering Journal, American I nstitu te of Steel Construc tio n, 2nd

Quarter, 1978*

C. W. Roeder and E. P. Popov. "Cyclic Shear Yielding of Wide Flange Beams,"

Journal of Engi neering Mechanics , ASCE, Vol. 104, No. EM4, August 1978.

Edward J. Teal. Practic a l Des ign of Eccentric Br aced Frames to Re sist

Seismic Forces . Structural Steel Educational Council, California Field

Ironworkers Administrative Trust, 1980,

Wo H. Smith, July 11, 1980 -bC-7
STRUCTURAL ENGINEERS ASSOCIATION

OF NORTHERN CALIFORNIA

PRESIDENT

ERIC ELSESSER

VICE PRESIDENT

JOSEPH P. NICOLETTI SECRETARY

MICHAEL A. JORDAN

TREASURER

TEO J. CANON

CONTROLLER

GEORGES E. BASSETT

DIRECTORS

TED J. CANON

LAWRENCE H. DANIELS

ERIC ELSESSER

PAUL F. FRATESSA

EPHRAIM G. HIRSCH

WILUAM T. HOLMES

MICHAEL A. JORDAN

JOSEPH P. NICOLETTI* EDWIN G. ZACHER

AST PRESIDENT

EDWIN G. ZACHER

2 June 1980

To Fritz Matthieson, Chairman Seismology Committee

From: Mark Saunders, Chairman Eccentric Braced Frame

Subcommittee

ECCENTRIC BRACED FRAME SUBCOMMITTEE

FINAL REPORT

HISTORY

This Subcommittee was formed as an ad hoc committee under

the Ductile Frame Subcommittee in March 1979. The original

and primary charge of the committee was to develop a "K"

factor for eccentric braced frames (EBF's). The Ad Hoc

Committee met in March and May of 1979 and in June drafted

preliminary recommendations which were presented briefly

to the State Seismology Committee. For the 1979-80 year,

the Ad Hoc Committee became a full subcommittee of the

Seismology Committee. We have met three times during the

year (November 1979, and February and April 1980), have

completed our recommendations for "K" factors, and have

drafted recommended code modifications and additions.

APPROACH

*

According to the Blue Book, the purpose of the "K" factor

"... is to give all types of structural systems an equal

probability of performance under a designated earthquake."

Thus, it is a relative factor and our approach was to

place the EBF in its appropriate relative position in the

,! K" factor table. In order to do this, we mainly considered

ductility; however, considerations of redundancy and the

effect of the "K" factor on overturning and diaphragms were

also incorporated.

171 SECOND STREET SAN FRANCISCO, CALIFORNIA 94105

EXECUTIVE SECRETARY - BILL GILES

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415-362-1721
ECCENTRIC BRACED FRAME SUBCOMMITTEE

SEAONC

FINAL REPORT

MS to F. Matthieson

2 June 1980

Page Two

RECOMMENDATIONS

Attached hereto is a copy of the "K" factor table (TABLE 1-A) , revised per our recommendations. Also attached is a draft of

recommended code language to be incorporated in the Blue Book.

After this material has been reviewed by all of the appropriate

bodies, we will undertake to write the final code language and

the commentary

.

ECCENTRIC BRACED SUBCOMMITTEE

Messrs. Alsmeyer, De Maria, Epstein, Kodavatiganti , Krawinkler,

Moore, Nicoletti, Nordenson, Popov, Shields, Smith, Warren,

Weathers, Merovich, Doig, Greenwood, Chang.

Ms. Kozler.

MS/hc

Attachments : a/s

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ATTACHMENT TO MEMO OF 6/2/80, MS to F. Matthieson DRAFT :MS/hc

6/2/30 , p.l

ECCENTRIC BRACED FRAME SUBCOMMITTEE

SEAONC

RECOMMENDED "K" FACTOR TABLE

INCORPORATING ECCENTRIC BRACED FRAMES

DRAFT

TABLE 1-A

HORIZONTAL FORCE FACTOR "K" FOR BUILDINGS

OR OTHER STRUCTURES

TYPE OR ARRANGEMENTS OF RESISTING ELEMENTS Value of "K"

Building with a box system as defined in

Section 1(B). 1.33

All building framing systems not otherwise classified herein. 1.00

Buildings with eccentric braced frames

designed in accordance with the following

criteria: the eccentric braced frames

shall have the capacity to resist the

total required lateral force and shall

be designed in accordance with the provisions specified in this code. 0.80

Buildings with a dual bracing system consisting of a ductile moment resisting

space frame and shear walls or braced

frames designed in accordance with the

following criteria:

1. The frame and shear walls or braced

frames shall resist the total lateral

force in accordance with their relative

rigidities considering the interaction

of the shear walls and frames.

C-10
ATTACHMENT TO MEMO OF 6/2/80, MS to F. Matthieson

TABLE 1-A ’ DRAFT :MS/hc

6/2/80 , p.2

TYPE OR ARRANGEMENT OF RESISTING ELEMENTS Value of "K"

2. The shear walls or braced frames acting

independently of the ductile moment

resisting space frame shall resist the ' total required lateral force.

3. The ductile moment resisting space

frame shall have the capacity to resist

not less than 25 percent of the required

lateral force. . 0.80

Buildings with a dual bracing system as

described above, except utilizing eccentric

braced frames in lieu of shear walls or

conventional braced frames. The eccentric

braced frames shall be designed in accordance with the provisions specified in

this code. 0.67

Buildings with a ductile moment resisting

space frame designed in accordance with

the following criteria: the ductile

moment resisting space frame shall have

the capacity to resist the total required

lateral force. 0.67

Elevated tanks plus full contents, on four

or more cross-braced legs and not supported

by a building. (1) (2) 2.50

Structures other than buildings and other

than those set forth in Table 1-B. 2.00

C-ll
ATTACHMENT TO MEMO OF 6/2/80, MS to F. Matthieson DRAFT :MS/hc

6/2/30 , p. 3

Section

Section

Section

(DRAFT)

RECOMMENDED ADDITIONS AND MODIFICATIONS

TO THE BLUE BOOK

DRAFT

1(B) Add a definition as follows:

"Eccentric Braced Frame is a braced frame

complying with the requirements given in

Section 5 of these Recommendations."

1(J)1. Revise to read as follows:

"a. Force Factor. All buildings designed

with a horizontal force factor K = 0.67

or 0.80, shall have ductile moment

resisting space frames or eccentric

braced frames."

After paragraph "g", insert the following:

"Eccentric Braced Frames. Design of eccentric braced frames shall conform to the

requirements of Section 5 of these Recommendations. Steel used shall be as required under

braced frames above.

STEEL ECCENTRIC BRACED FRAMES

(A) General

All of the provisions of Section 4 shall

apply to eccentric braced frames in addition to the requirements which follow.

(B) Definitions

LINK BEAM is that part of the beam which

is designed to yield in shear.

(C) Design Criteria

1) The link beam should be designed to

yield in shear at a force not less

than that obtained from an elastic

analysis of the frame, using the

lateral forces as prescribed by this

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ATTACHMENT TO MEMO OF 6/2/80, MS to F. Matthieson DRAFT :MS/hc

RECOMMENDATIONS - BLUE BOOK 6/2/80, p.4

Section 5

DRAFT (cont.) code, and factored to the plastic

design level. The shear yield shall

occur prior to bending yield. The

link beam web should be a single

thickness, without doublers.

2) Eccentric Braced Frames utilizing

bending yielding of the link beam

may utilize the "K" values as

described above if energy absorption

and ductility equivalent to that

obtained from the shear yielding

systems can be demonstrated. Otherwise they shall be assigned "K"

factors the same as concentric

braced frames.

3) Brace members shall be designed for

at least 1.5 times the axial forces

and moments which occur at onset of

link beam yielding.

4) Columns shall be designed using the

"strong column - weak beam" concept,

with the beam plastic moment capacity

limited to a reduced Mp consistent

with that allowed by the yielded web.

5) All of the requirements of Part 2 of

the AISC specification (Plastic Design)

shall be adhered to. Particular attention should be given to lateral bracing

of the beams and to the d/t ratio of

the link beam web. A lateral brace

must be placed at the point of intersection of the eccentric brace with

the beam unless adequate bracing by

some other system can be properly substantiated.

6) Axial forces, when occurring in the

link beam, shall be considered in

the design.

7) Appropriate consideration should be

given to the collapse mechanism for

extreme loading conditions.

C-13
ATTACHMENT TO MEMO OF 6/2/80, MS to F . Matthieson DRAFT :MS/hc

RECOMMENDATIONS - BLUE BOOK 6/2/80, p.5

Section 5

DRAFT (cont.) 8) Beam to Column connections shall

develop the full plastic moment

capacity of the beam and the full

shear yield capacity of the web.

Column flange and web stiffeners

should be designed according to the

usual methods.

9) Brace to beam connections will depend

on the brace section chosen. Primary

requirements are that a pair of stiffeners be provided in the beam at the

side of the connection defining the

end of the link beam, and that brace

forces be transferred directly to

these stiffeners by a flange (either

a flange of the brace or the flange

of a tee-shaped gusset) . In no case

should any component of the connection

extend into the link beam zone. The

connection should be designed with

the additional factor of safety required for the brace.

Added References 1. Roeder, C.W. and E.P. Popov, Inelastic

Behavior of Eccentrically Braced Steel

Frames Under Cyclic Loadings , EERC Report

77-18, University of California, Berkeley,

August 1977.

2. Roeder, C.W. and E.P. Popov, Eccentrically

Braced Steel Frames for Earthquakes , Journal of Structural Division, ASCE

,

Volume 104, No. ST3, March 1978.

3. Roeder, C.W. and E.P. Popov, Cyclic Shear

Yielding of Wide Flange Beams , Journal of

Engineering Mechanics, ASCE, Volume 104,

No. EM4 , August 1978.

C-14
flPPFHmx n

ORIGINAL WORKPLAN

FOR THE PROJECT

Revised 11/27/79

WORK PLAN FOR

REVIEW AND REFINEMENT OF TENTATIVE SEISMIC PROVISIONS

The Tentative Provisions for the Development of Seismic Regulations

were developed by the Applied Technology Council (ATC) in an effort that

included a wide range of experts in the actual drafting of the provisions.

Two external review drafts were circulated to a large portion of the

interested and informed community of eventual users. However, because

the Tentative Provisions are quite innovative, serious doubts about them

may exist. Prior to undertaking an expensive assessment of the Tentative

<0 Provisions through the conduct of trial designs, an attempt will be made

to investigate these doubts and to improve the Tentative Provisions where

possible. It is likely that many issues exist that will not be resolved

by this activity; some will require the information that will be developed

in the conduct of the trial designs and subsequent impact assessment

before resolution can be expected. However, the activity can and should

improve the likelihood that the trial designs and impact assessment will

not be conducted with provisions containing flaws so serious that the

results of the trial designs would be compromised. The activity can

also serve to focus the trial designs on particularly controversial

issues

.

GENERAL DESCRIPTION

The proposed review and refinement is designed to be accomplished

in less than a year, so that the overall assessment may proceed in a

timely fashion. The committee structure for carrying out the assessment

is shown in figure 1. Nine Technical Committees will be formed with

D-l
interests that collectively cover the Tentative Provisions . The Joint

Committee on Review and Refinement will consist of all voting members of

the Technical Committees. The chairmen of the Technical Committees will

form a Coordinating Committee.

The membership of each Technical Committee will be made up of

representatives of organizations that have particular interest in the

Tentative Provisions ; the invited participants are listed on attachment 1.

Because the individual Technical Committees are each formed of specialists

and are focused on a small portion of the Tentative Provisions , they may

not be well balanced. The full Joint Committee membership is pore

balanced, however, and the final and decisive ballot on any refinements

will involve the entire Joint Committee. It is important to realize

that this activity is neither the development of a draft standard nor

the affirmation of a standard, only a mid^-course adjustment thought

necessary for wise expenditure of research funds for the conduct of

trial designs and impact assessment .

In addition to the voting members, each Technical Committee will

include a non-voting member from each of the following organizations:

ATC, the Building Seismic Safety Council (BSSC) and the National Bureau

of Standards (NBS) . The ATC representative will be a technical resource

to the committee. He will have been closely involved with the development

of the provisions of interest to the committee. The NBS representative

will be the technical secretary for each committee and will convene the

first meeting and provide technical and administrative support throughout

the effort. The BSSC representative will provide overview with appropriat

committees of the BSSC. Each Technical Committee will elect a chairman
from among its voting members and will develop its own agenda for review

and refinement, within the general guidelines established for scheduling,

for coordination of refinements, and for documentation.

The Coordinating Committee, will be formed from the chairmen of the

nine committees and will be chaired by NBS. A representative of both

ATC and BSSC will also be included, but neither of them nor the NBS

chairman will be voting members. The Coordinating Committee will review

all refinements proposed by the other committees with the express purpose

of preventing the development of conflicts and inconsistencies. Their

operation is described in more detail in subsequent paragraphs.

The Joint Committee will be headed by a nonvoting NBS chairman.

NBS will also provide support for convening and operating the Joint

Committee.

OBJECTIVES AND GUIDELINES

The Tentative Provisions employ several new concepts that need

thorough assessment, which is what the trial designs are intended to

help provide. The objective of this activity is to assure that the

provisions used in the trial designs do allow such an assessment and to

focus the trial designs on particularly controversial issues. It is

intended that this activity assure, to the extent possible, that the

information necessary to reach a consensus on the new concepts will be

available following the trial designs. It is not expected that a consensus

will be reached on all issues before the trial designs. Questioning the

technical merit of a provision and questioning how effective a provision

D-3
is in implementing a new concept are well within the scope of the activity.

However, it is beyond the scope to radically alter the new concepts

embodied in the Tentative Provisions .

%

The fact that the Technical Committees are established to refine

the Tentative Provisions but are not encouraged to grossly change them

requires the establishment of clear guidelines, which is difficult. The

introduction to the Tentative Provisions includes lists of objectives

and new concepts, which are on attachment 2. The best available

guidelines seem to be that these objectives shall not be compromised nor

shall sweeping changes be made to the new concepts. Refinements violating

these guidelines will be discouraged. If such refinements do result

they will be documented and the advice of 3SSC will be sought concerning

their use in the trial designs and impact assessment.

The purpose of this NBS activity is to review the ATC3-06 provisions

and present a recommended set of seismic design provisions and test

procedures to BSSC. NBS will provide to BSSC documentation on all

actions made to revise the ATC documents. This includes both successful

and unsuccessful proposed changes. Upon receipt of these recommendations

the BSSC membership shall consider by ballot these recommendations and

any revisions proposed to them according to BSSC adopted procedures. The

overview committee, its members or delegates shall be afforded the

opportunity to participate in any and all activities with timely access

to all documents and correspondence. The overview committee will

periodically advise NBS of its observation on the conduct of the activity

and as required recommend to the BSSC Board corrective actions. Board

recommendations to NBS will be resolved to both parties satisfaction. No

D-4
trial designs will be conducted under this overall program until the

BSSC has approved both the provisions to be tested and the test procedures.

OPERATIONS AND SCHEDULE

NBS will commence the activity by inviting each organization to

provide representatives to the Committees as listed on attachment 1.

NBS will then convene all the Committees for a one-day meeting on

December 11. At this time preliminary material will be distributed, the

objectives, guidelines, operating policies, and the schedule will be

discussed, the committees will select their chairmen, and discussion of

the issues for review and refinement will begin. The remainder of this

section describes policies and schedules (a schedule is shown on figure 2).

Following the initial meeting, Technical Committee members and

other individuals will submit their proposed revisions, in writing and

with supporting evidence and reasoning, to the committee secretaries by

January 11, 1980. The secretary will then send the proposed revisions

to the ATC representative for his review and comment. His review comments

will be due back to the secretary by January 30, 1980.

All suggested proposed revisions and ATC responses will be distributed

to the committee members prior to the individual committee working

meetings scheduled for February. These meetings will constitute the

primary opportunity for individual committees to deliberate on the

issues, and they may extend over several days. Each Technical Committee

secretary will then conduct a letter ballot of his Committee covering

all revisions proposed for ballot at the working meetings, and will then

make the results available to the members of the Coordinating Committee
in advance of their meeting (scheduled for early April). A simple

majority will be required to send a proposed revision to the Coordinating

Committee.

The Coordinating Committee will identify and resolve all conflicts

and inconsistencies created by the proposed revisions of the individual

Technical Committees. The Coordinating Committee has the authority to

modify the proposal of an individual Technical Committee, to drop any

proposal from further consideration, and to combine related proposals

from different committees into single proposals. The objective of the

Coordinating Committee is to come up with a set of proposed refinements

to be discussed at the final meeting of the Joint Committee. Actions of

the Coordinating Committee will be carried by a simple majority, except

that any individual Technical Committee chairman has the right to place

a proposal from his committee that was dropped by the Coordinating

Committee on the agenda of the final meeting as a special issue.

Each participant will receive the set of proposed revisions prior

to the final Joint Committee meeting (scheduled for May or June). In

order to assure each participant's understanding of the ballot issues,

each proposed revision will be presented with a concise exposition of

pro and con and discussion will be allowed at the final meeting. Upon

leaving the final meeting, each voting member will be given a letter

ballot, which he is to return within two weeks. Each member will be

expected to vote on all proposed revisions. A two-thirds majority of

votes cast will be necessary for adoption of any change. NBS will

compile the revisions, both proposed and adopted, into a final report

D-6
with appropriate documentation for any changes suggested to the Tent at ive

Provisions and for the conduct of the trial design and impact assessment

activity.

Each of the Technical Committees should examine each proposed

provision with regard to the need for early test designs and refer such

need to the Coordinating Committee. NBS will work with the Coordinating

Committee to expedite carrying out needed designs.

D-7
)'

JOINT COMMITTEE ON

REVIEW AND REFINEMENT

COORDINATING

COMMITTEE

TECHNICAL COMMITTEES

Committee 1: Seismic Risk Maps

Committee 2 : Structural Design

Committee 3: Foundations

Committee 4: Concrete

Committee 5: Masonry

Committee 6: Steel

Committee 7 : Wood

Committee 8

Mechanical,

Architectural,

and Electrical

Committee 9: Regulatory Use

Figure 1: Committee Structure

D-8
,/

Figure 2 - SCHEDULE

1979 1980

Activity Nov Dec Jan Feb Mar Apr May Jun Jul Aug

1. Initial Joint Committee and

Technical Committee Meeting

Dec 11

2. Submission of Proposals

3. Review by ATC —

4. Individual Working Meetings —

5. Letter Ballots —

6. Coordinating Committee :

k

7. Final Jo int Meet ing *

8. Final Ballot —

9. Report ~ —0

D-9
Attachment 1 - TECHNICAL COMMITTEE MEMBERSHIP

COMMITTEE 1: Seismic Risk Maps

Voting Members

American Society of Civil Engineers

Association of Engineering Geologists

Interagency Committee on Seismic Safety in Construction

Seismological Society of America

Structural Engineers Association of California

United States Geological Survey

Nonvoting Members

ATC Representative

BSSC Overview

NBS Secretariat

COMMITTEE 2: Structural Design

Voting Members

American National Standards Institute

American Society of Civil Engineers

Interagency Committee on Seismic Safety in Construction

Structural Engineers Association of California

Representative from Committee 3 (Foundations)

Representative from Committee 4 (Concrete)

Representative from Committee 5 (Masonry)

Representative from Committee 6 (Steel)

Representative from Committee 7 (Wood)

Nonvoting Members

ATC Representative

BSSC Overview

NBS Secretariat

COMMITTEE 3: Foundations

Voting Members

American Society of Civil Engineers

American Society of Foundation Engineers

Interagency Committee on Seismic Safety in Construction

Structural Engineers Association of California

Nonvoting Members

ATC Representative

BSSC Overview

NBS Secretariat
COMMITTEE 4: Concrete

Voting Members

American Concrete Institute

American Society of Civil Engineers

Interagency Committee on Seismic Safety in Construction

Concrete Reinforcing Steel Institute

Portland Cement Association

Post- Tensioning Institute

Prestressed Concrete Institute

Nonvoting Members

ATC Representative

BSSC Overview

NBS Secretariat

COMMITTEE 5 : Masonry

Voting Members s

American Concrete Institute

American National Standards Institute

American Society of Civil Engineers

Brick Institute of America

Masonry Institute of America

National Concrete Masonry Association

The Masonry Society

Western States Clay Products Institute

Nonvoting Members

ATC Representative

BSSC Overview

NBS Secretariat

COMMITTEE 6: Steel

Voting Members

American Institute of Steel Construction

American Iron and Steel Institute

American Society of Civil Engineers

Interagency Committee on Seismic Safety in Construction

Metal Building Manufacturers Association

Steel Plate Fabricators Association

Nonvoting Members

ATC Representative

BSSC Overview

NBS Secretariat

D- n
COMMITTEE 7: Wood

Voting Members

American Institute of Timber Construction

American Plywood Association

American Society of Civil Engineers

Interagency Committee on Seismic Safety in Construction

National Forest Products Association

United States Forest Product Laboratory

Nonvoting Members

ATC Representative

BSSC Overview

NBS Secretariat

COMMITTEE 8: Architectural, Mechanical, and Electrical

Voting Members

American Institute of Architects

American Society of Civil Engineers

American Society of Heating, Refrigerating and Air Conditioning

American Society of Mechanical Engineers

American Society of Plumbing Engineers

Brick 'Institute of America

Institute of Electrical and Electronics Engineers

Interagency Committee on Seismic Safety in Construction

National Elevator Industry, Inc.

National Fire Protection Association

Nonvoting Members

ATC Representative

BSSC Overview

NBS Secretariat

COMMITTEE 9: Regulatory Use

Voting Members

American Institute of Architects

American Insurance Association

American Society of Civil Engineers

Associated General Contractors of America

Association of Major City Building Officials

Building Officials and Code Administrators International

Building Owners and Managers Association

Construction Research Council

Construction Specifications Institute

International Association of Electrical Inspectors

International Association of Plumbing and Mechanical Officials

International Conference of Building Officials

National Conference of States on Building Codes and Standards

D- 12
National Electrical Manufacturers Association

Southern Building Code Congress International

Nonvoting Members

ATC Representative

BSSC Overview

NBS Secretariat

D-13
Attachment 2 - "Objectives" and "New Concepts"

The following "OBJECTIVES" and "NEW CONCEPTS" are quoted directly from

the ATC-3 document as an aid in establishing guidelines for the proposed

review and refinement.

OBJECTIVES

During the early stages of the ATC-3 project, much time and effort

was expended to establish the project objectives. For guidance in understanding the project goals and this document, the objectives are listed

below:

1. To evaluate the knowledge acquired in recent research and experience

gained during on-site observations of the effects of earthquakes and

to assemble it in a concise and comprehensive document for general

use by building design professionals and others.

2. To write the tentative design provisions so as to permit, insofar

as possible, ingenuity of solution, but with definitive criteria

to evaluate the resulting design.

3. To provide seismic protection criteria which will be applicable

to all probable earthquake areas of the United States.

4. To recognize that acceptable seismic risk is a matter of public

policy determined by a specific government body and should be

based upon:

(a) An evaluation of available technical knowledge, including

the areas of seismicity.

(b) Reasonable means available for protection.

(c) The magnitude of the earthquake risk cotnpared with acceptable

risks for other hazards.

(d) The economical and social impact of a major catastrophe.

5. To provide tentative design provisions applicable to all

buildings, including existing buildings, and appropriate

structural as well as nonstructural components. To include

requirements for structural analysis, design, and detailing

which will provide adequate earthquake resistance for typical

buildings and to make recommendations with respect to the

design of atypical buildings.

6. To recognize that for critical facilities there should be

. consideration in the design of building structural and nonstructural systems of limiting damage in order to maintain

the level of function determined to be necessary.

7. To provide a commentary to assist the user in understanding

the intent and background of the provisions and to assess the

D- 14
implications of any alterations made to the provisions in the

future.

NEW CONCEPTS

The provisions embody several new concepts listed below which are

significant departures from existing seismic design provisions. Consequently, the provisions should not be considered for code adoption

until a detailed evaluation is made of their workability, practicability,

and potential economic impact.

1. The incorporation of more realistic seismic ground motion

intensities.

2. Consideration of the effects of distant earthquakes on longperiod buildings. ;

3. Response modification coefficients (reduction factors) which are based on consideration of the inherent toughness, amount of damping

when undergoing inelastic response, and observed past performance

of various types of framing systems.

4. Classification of building use-group categories into "Seismic Hazard

Exposure Group."

5. Seismic performance categories for buildings with design and analysis

requirements dependent on the seismicity index and building seismic

hazard exposure group.

6. Simplified structural response coefficient formulas related to the

fundamental period of the seismic resisting system of the building.

7. Detailed seismic design requirements for architectural, electrical,

and mechanical systems and components.

8. Materials design and analysis based upon stresses approach yield.

9. Guidelines for systematic abatement of seismic hazards in existing

buildings.

10.

Guidelines for assessment of earthquake damage, strengthening or repair of damaged buildings, and potential seismic hazards in

existing buildings.
I
APPENDIX E

ROSTER OF PARTICIPANTS
1
COMMITTEE 1: Seismic Risk Maps

American Society of Civil Engineers

Mr. William F. Marcuson, III

Waterways Experiment Station

P.0. Box 631 ( .) Vicksburg, Mississippi 39180

Phone: Office - 601-636-3111 ext. 2217 FTS 542-2217

Home - 601-638-1704

Association of Engineering Geologists

Howard A. Spellman

Converse Ward Davis Dixon Association

126 W. Delmar Boulevard \ Pasadena, California 91105

Phone: Office - 213-795-0461

Home - 213-359-5112

Interagency Committee on Seismic Safety in Construction

Mr. Jerry Harbour

Chief, Site Safety Research Branch

U.S. Nuclear Regulatory Commission

Mail Sta. 113055

Washington, D.C. 20555

Phone: 301-427-4370

Structural Engineers Association of California

Dr. Robert Englekirk (representative to Committee

3242 West 8th Street Structural Design)

Los Angeles, California 90005

Phone: 213-385-9487

United States Geological Survey

S. T. Algermissen (Chairman)

U.S. Geological Survey

Denver Federal Center

Box 25046 MS966

Denver, Colorado 80225

Phone: Office - 303-234-4014

Home - 303-755-4024

E-l
Committee 1 (continued)

Applied Technology Council

Mr. Neville C. Donovan

Partner, Dames & Moore

500 Sansome St.

San Francisco, CA 94111

Phone: (415) 433-0700

Building Seismic Safety Council

Mr. William Le Messurier

Chairman, Sippican Consultants

International, Inc.

1033 Massachusetts Ave.

Cambridge, Massachusetts 02138

Phone: 617-868-1200

National Bureau of Standards

Dr. Bruce Ellingwood

Secretariat

Committee 1, Seismic Risk Maps

National Bureau of Standards

Pm. B168 , Bldg. 226

Washington, D. C. 20234

Phone: 301-921-2170

(Dr. Riley Chung)

Phone: 301-921-2137

E-2
COMMITTEE 2: Structural Design

American National Standards Institute

Dr. Howard Simpson

Simpson Gumpertz & Heger Inc.

1696 Massachusetts Ave.

Cambridge, MA 02138

Phone: 617-491-8300

American Society of Civil Engineers

Mr. Hal Iyengar (Chairman of the Committee)

Skidmore, Owing s & Merrill

30 West Monroe St.

Chicago, Illinois 60603

Phone: 312-346-6161

Interagency Committee on Seismic Safety in Construction

Dr. Richard D. McConnell

Veterans Administration (08 5A)

810 Vermont Avenue, N.W.

Washington, D. C. 20420

Phone: 202-389-3103 or 23 Q 4

Structural Engineers Association of California

Mr. Nicholas For ell

Forell/Elsesser Engrs.

631 Clay St.

Third Floor

San Francisco, Calif. 94111

Phone: 415-397-2768

Representative from Committee 1 (Seismic Risk)

Alter: Dr. Rene W. Luft

(send mail c/o Howard Simpson)

Dr. Robert Englekirk

3242 West 8th Street

Los Angeles, California 90005

Phone: 213-385-9487

Representative from Committee 3 (Foundations)

Mr. Joseph V. Tyrrell

Director, Civil/Struc. Div.

Naval Facilities Engineering Comnd

.

200 Stoval Street

Alexandria, VA 22332

Phone: 703-325-0064

E-3
Committee 2 (continued)

Representative from Committee 4 (Concrete )

Mr. Mark Pint el

Portland Cement Association

Engineering Development Department

5420 Old Orchard Road

Skokie, Illinois 60077

Phone: 312-583-6200

Representative from Committee 5 (Masonry)

Mr. Alan Yorkdale

Brick Institute of America

1750 Old Meadow Lane

McLean, VA 22101

Phone: 703-893-4010

Representative from Committee 6 ('Steel)

Mr. William A. Sontag

Pascoe Steel Corporation

P. 0. Box 2628

Pomona, CA 91766

Phone: 714-623-1411

Representative from Committee 7 (Wood')

Mr. Edwin G. Zac her

H. J. Brunier Associates

55 Mew Montgomery

Suite 608

San Francisco, California 94105

Phone: 415-731-0370

Applied Technology Council

Mr. Roland L. Sharpe Mr. Rolan

Managing Director EDAC

Applied Technology Council or 4 80 Cal i

7

2150 Shattuck Avenue, Suite 806

Berkeley, CA 94704

Phone: 415-540-0223

Palo Alt -

Phone :

;v, =

o i*n i s.

, CA

.“I Q

E-
Committee 2 (continued)

Building Seismic Safety Council

Dr. Aj it S. Virdee

Rumberger /Haines/Virdee and Associates

Consulting Civil and Structural Engineers

420 Broadway

Sacramento, CA 95818

Phone: 916-446-6128

Mr. William J. LeMessurier (alternate)

Sippican Consultants International

1033 Massachusetts Ave.

Cambridge, Mass. 02138

Phone: 617-868-1200

National Bureau of Standards

Mr. James Harris

Secretar iat

Committee 2, Structural Design

National Bureau of Standards

Rn. B168, Bldg. 226

Washington, D. C. 20234

Phone: 301-921-2170

( Dr. Tim Reinhold)

Phone: 301-921-2186

E-5
COMMITTEE 3 : Foundat ions

I

s

American Society of Civil Engineers

Mr. James G. LaBastie _ j£

6252 Powell Road

Parker, Colorado 80134

Phone: 303-771-3641

1

Association of Soil and Foundation Engineers

Mr. Richard Simon (Chairman) J

Goldberg, Zoino, Dunnicliff & Assoc., Inc.

30 Tower Road

Newton Upper Falls, Massachusetts 02164

Phone: 617-969-0050

Interagency Committee on Seismic Safety in Construction

Mr. Joseph V. Tyrrell (representative to Committee 2: Structural Desit

Director, Civil/Struc. Div.

Naval Facilities Engineering Comnd.

200 Stovall Street

Alexandria, VA 22332

Phone: 202-325-0064

Structural Engineers Association of California

Mr. William Travis

7851 Mission Center Court

Suite 250

San Diego, California 92108

Phone: 714-291-2800

Applied Technology Council

Mr. Henry Degenkolb

H. J. Degenkolb & Associates

350 Sansome Street

San Francisco, CA 94104 Phone: 415-392-6952

Building Seismic Safety Council

Mr. Leroy Crandall, President

L. Leroy Crandall and Associates

711 North Alvarado Street

Los Angeles, CA 90026

Phone: 213-413-3550 u-o
Committee 3 (continued)

National Bureau of Standards

Mr. Larry Salomone

Secretariat

Committee 3, Foundations

National Bureau of Standards

Rm. B168, Bldg. 226

Washington, D. C. 20234

Phone: 301-921-3128

(Dr. Riley Chung)

Phone: 301-921-2137

Send all correspondence to:

Mr. Frank M. Fuller

Vice President

Raymond International Builders, Inc.

0. Box 22718

Houston, TX 77027
COMMITTEE 4: Concrete

American Concrete Institute

Edward Cohen (Chairman)

Ammann & Whitney, Consulting Engineers

Two World Trade Center

New York, New York 10048

Phone: 212-938-8267

American Society of Civil Engineers

Eugene P. Holland

President

Coder-Tavlor Assocs., Inc.

500 Greenbav Road

Kenilworth, Illinois 60043

Phone: 312-441-4200

Concrete Reinforcing Steel Institute

Joseph G. Manning

Regional Director

Concrete Reinforcing Steel Institute

'Western Region

1-99 Bayshore Highway

Suite 113

Burlingame, California 94010

Phone: ->15-697-1437

Interagency Committee on Seismic Safety in Construction

James D. Prendergast

I’.S. Army - P.0. Bex -*005

Construction Engineering Research Laboratory

Champaign, Illinois 61820

Phone: 217-352-6511 Ext. 2-2

Portland Cement Association

Mark Pint el

Portland Cement Association

5420 Old Orchard Road

Skokie, Illinois 60077

Alternate: Gene Corley

(same address as Fintei)

(representative on Committee

Structural Desicn) - Fintei

Phone: 312-966-6200

E-8
I n

*

*

«

*

i

i

i

Committee 4 (continued)

Post-Tensioning Institute

Neil Hawkins

Professor and Chairman

Department of Civil Engineering

University of Washington

201 More Hall FX-10

Seattle, Washington 98195

Phone: 206-543-2575

Prestressed Concrete Institute

David A. Sheppard A1

California Marketing Director

Prestressed Concrete Institute

1350 Del Rio Court

Concord, California 94518

Phone: 415-957-1327

ernate: Daniel P. Jenny

Technical Director

Prestressed Concrete Institute

20 North Wacker Drive

Chicago, Illinois 60606

Phone: 312-346-4071

Structural Engineers Association of California

Loring A. Wyllie, Jr.

H. J. Degenkolb Associates

350 Sansome Street

San Francisco, California 9410-

Phone: 415-392-6952

Applied Technology Council

V. V. Bertero

Professor of Civil Engineering

Department of Civil Engineering

783 Davis Hall

University of California

Berkeley, California 94720

Phone: 415-642-3655

Building Seismic Safety Council

James Lefter

Director, Civil Engineering Service (085)

Lafayette Building, Room 507

811 Vermont Avenue, NW

Washington, D.C. 20420

Phone: 202-389-2864

E-9
Committee 4 (continued)

National Bureau of Standards

Richard D. Marshall and Kyle Woodward

Secretariat

Committee 4, Concrete

National Bureau of Standards

Room B168, Building 226

Washington, D.C. 20234

Phone: 301-921-3471 (Marshall)

301-921-2885 (Woodward)

' - i r

)
COMMITTEE 5 : Masonry

American Concrete Institute

Mr. Richard M. Gensert

Consulting Engineer

718 The Arcade

Cleveland, Ohio 44114

Phone: 216-241-7078

American Society of Civil Engineers

Mr. Jerry G. Stockbridge (Co-Chairman)

600 Fairway Drive

Glenview, Illinois 60025

Phone: 312-272-7400

Brick Institute of America

Mr. Alan H. Yorkdale

Brick Institute of America

1750 Old Meadow Road

McLean, YA 22101

Phone: 703-893-4010

Interagency Committee on Seismic Safety in Construction

Mr. Andrei Gerich

Structural Engineering Division

Office of Architecture & Engineering Stds.

Department of Housing and Urban Development

Room 6172

Washington, D.C. 20410

Phone: 202-755-5924

Masonry Institute of America

(Representative to Committee 2:

Structural Design)

Mr. James E. Amrhein

Director of Engineering

2550 Beverly Boulevard

Los Angeles, California 90057

Phone: 213-388-0472

National Concrete Masonry Association

Alternate: Mr. Kevin Callahan

(same address as Hogan)

Phone: 703-435-4900

Mr. Mark Hogan

National Concrete Masonry Association

P.0. Box 781

Herndon, Virginia 22070

E-ll
Committee 5 (continued)

Portland Cement Association

Mario Catani Alternate: Albert W. Isberner

Portland Cement Association (address same as Catani)

Buildings Division

5420 Old Orchard Road

Skokie, Illinois 60077

Phone: 312-583-6200 Ext. 366

Structural Engineers Association of California

Ed Johnson

Atkinson, Johnson & Spurrier

4121 Napier Street

San Diego, California 92110

Phone: 714-275-1530

The Masonrv Society

George Hanson, P.E. (Co-Chairman)

President, The Masonry Society

3003 South Williams

Denver, Colorado 80210

Phone: 303-427-6443 (office in home

)

Western States Clay Products Association

Donald A. Wakefield, P.E.

Vice President

Interstate Brick 4 Ceramic Tile

9210 South 5200 West

P.0. Box 517

West Jordan, Utah 840SPhone: 801-561-1471

Applied Technology Council

Mr. Melvyn Mark

Structural Engineer

Ferver Eng. Co.

3487 Kurtz Street

San Diego, California 92110

Phone: 714-224-3501

E-12
Committee 5 (continued)

Applied Technology Council

Dr. Ron Mayes

Applied Technology Council

2150 Shattuck Avenue, Suite 806

Berkeley, California 94704

Phone: 415-540-0223

Building Seismic Safety Council

Mr. Vincent Bush

International Conference of Building Officials

5360 South Workman Mill Road

Whittier, California 90601

Phone: 213-699-0541

National Bureau of Standards

Dr. E. V. Leyendecker

Secretariat

Committee 5, Masonry

National Bureau of Standards

Room B168, Building 226

Washington, D.C. 20234

Phone: 301-921-3471

(Mr. Lou Cattaneo)

Phone: 301-921-2184

E-13
COMMITTEE 6: Steel

American Institute of Steel Construction

William A. Milek

American Institute of Steel Construction, Inc.

Wrigley Building

400 North Michigan Ave.

Chicago, ILL 60611

Phone: 312-670-2400

American Iron and Steel Institute

Dr. Albert L. Johnson

Staff Representative

American Iron and Steel Institute

1000 16th Street, N.W.

Washington, D.C. 20036

Phone: 202-452-7184

American Society of Civil Engineers

Mr. Jerry Iff land (Chairman)

Iff land, Kavanagh, Waterbury

2501 Broadway

22 ew York, New York 10036

Phone: 212-933-2000

Alter : Mr. William H. Smith

Regional Director

American Iron L Steel

Inst itute

Latham Square Build in

508 Sixteenth Street

Suite 704

Oakland, CA 9-612

Phone: 415-763-6751

Interagency Committee on Seismic Safety in Construction

Mr. John B. Scalzi

National Science Foundation

Room 1130

1800 G Street N. W.

Washington, D.C. 20550

Phone: 202-632-0648

Metal Building Manufacturers Association

Mr. William A. Sontag

Pascoe Steel Corporation

P. 0. Box 2628

Pomona, CA 91766

Phone: 714-623-1411

(representative to Committee 2)

Alter: Duane Ellifrit

Director of Research 1 Engineering

Metal Building Manuractu

Assoc

.

1230 Keith Buildin

Cleveland, OH 441

E-14

01)

rH
Committee 6 (continued)

Steel Plate Fabricators Association

Mr. Norman K. Cohn

Chief Engineer

Mississippi Valley Structural Steel Co.

Sub. of Bristol Steel & Iron Works

3117 Big Bend Blvd.

St. Louis, MO 63143

Phone: 314-644-2200

Applied Technology Council

Mr. Clarkson Pinkham

President, S B Barnes Assoc.

2236 Beverly Blvd.

Los Angeles, CA 90057

Phone: 213-382-2385

Building Seismic Safety Council

Mr. Charles De Maria

Building Seismic Safety Council

H. J. Brunnier Associates

Structural Engineers

55 New Montgomery Street

Suite 608

San Francisco, CA 94105

Phone: 415-781-0370

National Bureau of Standards

Dr. H. S. Lev

Secretariat

Committee 6, Steel

National Bureau of Standards

Rm. B168 , Bldg. 226

Washington, D. C. 20234

Phone: 301-921-2647

E-15
COMMITTEE 7: Wood

American Institute of Timber Construction

Mr. Thomas E. Brassell

Vice President of Technical Services

American Institute of Timber Construction

333 West Hampden Avenue

Englewood, Colorado 80110

Phone: 303-761-3212

American Plywood Association

Mr. Daniel H. Brown (Chairman)

American Plywood Association

P.0. Box 11700

Tacoma, Washington 98411

Phone: 206-565-6600

American Society of Civil Engineers

Mr. Thomas G. Williamson

Laminated Fabrication, Inc.

1716 Broad Ripple Avenue

Indianapolis, Indiana 46220

• Phone: 317-251-1455

Interagency Committee on Seismic Safety in Construction

Mr. Marco F. Venturino

Supervisor, Structural Engineering

Western Division

Naval Facilities Engineering Command

P.0. Box 727

San Bruno, California 94066

Phone: 415-877-7340

National Forest Products Association

Roderick B. Buchan

National Forest Products Association

Forest Industries Building

1619 Massachusetts Avenue, NW

Washington, D.C. 20036

Phone: 202-797-5882

E-16
Committee 7 (continued)

United States Forest Products Laboratory

Mr. Lawrence A. Soltis, Engineer

U.S. Forest Products Laboratory

P.0. Box 5130

Madison, Wisconsin 53705 Phone: 608-264-5600

Applied Technology Council

Mr. Edwin G. Zacher

H. J. Brunier Associates

55 New Montgomery

Suite 608

San Francisco, California

Phone: 415-781-0370

Building Seismic Safety Council

Mr. Roy G. Johnston

Brandow & Johnston Associates

1660 W. 3rd Street

Los Angeles, CA 90017

Phone: 213-484-8950

National Bureau of Standards

(representative to Committee 2

Design)

94105

Mr. Charles Yancey

Secretariat

Tentative Seismic Provision Project

Committee 7 : Wood

National Bureau of Standards

Rm. B168 , Bldg. 226

Washington, D.C. 20234

Phone: 301-921-2137

Structural

E-17
COMMITTEE 8: Architectural, Mechanical, and Electrical

American Institute of Architects

Mr. Robert Sockwell (Chairman)

AIA Research Corp.

1735 New York Ave. , N.W.

Washington, D. C. 20006

Phone: 202-626-7441

American Society of Civil Engineers

Mr. Bruce C. Olsen

1411 4th Ave. Bldg.

Suite 1420

Seattle, Washington 98101

Phone: 206-624-7045

American Society of Heating, Refrigerating and Air Concit ior.in

Mr. Shigeki Hiratsuka

406 South Barton

Arlington, VA 22204

Phone: 202-252-4950 (DoE) temporary

American Society of Mechanical Engineering

Mr. Philip Lathrap

c/o Pacific Gas and Electric Co.

77 Beale Street

Room 2883

San Francisco, CA 94106

Phone: 415-781-4211 X1605

American Society of Plumbing Engineers

Mr. Stephen D. Heath, P.E.

American Society of Plumbing Engineers

15233 Ventura Blvd.

Suite 616

Sherman Oaks, CA 91403

Phone: 213-783-4845

Home Address

Holmes and Nar.’er , Inc.

Engineers Contractor

999 Town and Count r

- Ed.

Orange, CA 926bS

E-18
Committee 8 (continued)

Brick Institute of America

Joseph A. Wintz, III

Brick Institute of America

1750 Old Meadow Road

McLean, Virginia 22101

Phone: 703-893-4010

Interagency Committee on Seismic Safety in Construction

Mr. Mark Swat t

a

Veterans Administration (085A)

810 Vermont Avenue, NW

Washington, D.C. 20420

Phone: 202-389-3103

National Elevator Industry, Inc.

Mr. George Gibson

Otis Elevator Company

440 Franklin Turnpike

Mahwah, New Jersey 07430.

Phone: 201-825-4400

Applied Technology Council

Mr. Tom Wosser

Corp. Officer

H. J. Degenkolb Associates

350 Sansome Street

San Francisco, California 94104

Phone: 415-392-6952

Building Seismic Safety Council

Mr. Christopher Arnold

Building Systems Development Inc.

120 Broadway

San Francisco, California 94111

Phone: 415-434-3830

E-19
Committee 8 (continued)

National Bureau of Standards

Mr. Tom Faison

Secretariat

Tentative Seismic Provision Project

Committee 8, Architectural, Mechanical and Electrical

National Bureau of Standards

Room B168, Building 226

Washington, D.C. 20234

Phone: 301-921-3293

Dr. James R. Shaver

Tentative Seismic Provision Project

Committee 8, Architectural, Mechanical and Electrical

National Bureau of Standards

Room B168, Building 226

Washington, D.C. 20234

Phone: 301-921-2186

E-20
COMMITTEE 9: Regulatory Use

American Institute of Architects

John Fisher

Skidmore, Owings and Merrill

1 Maritime Plaza ! San Francisco, California 94111

Phone: 415-981-1555

American Insurance Association

Mr. Michael Sbaglia

American Insurance Association

85 John Street

New York, N.Y. 10038

/ & Phone: 212-433-4412

.American Society of Civil Engineers

Norton S. Remmer, P.E. (Chairman)

Commissioner

Dept, of Code Inspection

419 Belmont St.

Worcester, Mass. 01604

Phone: 617-798-8111

Associated General Contractors of America

Mr. Campbell L. Reed

The Associat ed General Contractors of America

Director, Building Division

1957 E Street, N.W.

Washington, D.C. 20006

Phone: 202-393-2040

Association of Major City Building Officials

Jack M. Fratt, General Manager

Department of Buildings and Safety

200 North Spring Street

Los Angeles, CA 90012

Phone: 213-485-2341

E-21
Committee 9 (continued)

Building Officials and Code Administrators International

Paul K. Heilstedt

Building Officials & Code Administrators International

Technical Director

17926 South Halsted

Homewood, Illinois 60430

Phone: 312-799-2300

Building Owners and Managers Association

Mr. Lenny Rosenberg Alternate: Mr. Neal D. Houghton

Vice President, Operations 2907 E. Fairmount

Chesapeake Life Insurance Phoenix, Arizona 85016

527 St. Paul Street

Baltimore, Maryland 21202 Phone: 602-955-1973

Phone: 301-727-6400

Interagency Committee on Seismic Safety in Construction

Mr. G. Robert Fuller

Structural Engineer

Office of Architecture & Engineering Stds.

Department of Housing 4 Urban Development

Room 6172

Office of Housing

Washington, D.C. 20411

Phone: 202-755-5924

International Association of Plumbing and Mechanical Officials

Mr. Jack Allen Alternate: Tom Higham

11471 Phoebe Court Execut ive Direc tor

Smartville, California 95977 International Associate

Plumbing 4 Mechanical

Phone: 916-272-5532 5032 Alhambra Avenue

Los Angeles, California

Phone : 916-272-5532

E-2 2
Committee 9 (continued)

International Conference of Building Officials

Mr. Ralph C. Grippo

Department of Building Safety

3031 Torrance Boulevard

Torrance, California 90503

Phone: 213-328-5310

National Academy of Code Administration

International Conference of Building Officials

5360 S. Workman Mill Road

Whittier, California 90601

Phone: 213-699-0541

Mr. James M. Hicks, Jr.

Chief, Div. of Building Code Enforcement

Montgomery County Department of

Environmental Protection

6110 Executive Boulevard

Rockville, Maryland 20852

Phone: 301-468-4126

National Association of Home Builders

David E. Johnson, P.E.

Assistant Director

Technical Services Department

National Association of Home Builders

15th 4 M Streets, NW

Washington, D.C. 20005

Phone: 202-452-0360

National Conference of States on Building Codes and Standards

Mr. William Dripps

Director, Codes and Standards

National Conference of States on Building Codes

4 Standards

1970 Chain Bridge Road

McLean, Virginia 22102

Phone

:

703-790-5750
Committee 9 (continued)

Southern Building Code Congress International, Inc .

William J. Tangye, P. E.

Director of Engineering Services

Southern Building Code Congress

International, Inc.

900 Montclair Road

Birmingham, Alabama 35213

Phone: 205-591-1853

Applied Technology Council

Mr. Warner Howe, P. E.

Owner, Gardner & Howe

1255-A Lynnfield Rd

.

Suite 194 * Memphis ,* Tenn . 38138

Phone: 901-761-1580

Building Seismic Safety Council

Mr. Donald F. Pinkerton

National Conference of States

on Building Codes & Standards

1970 Chain Bridge Road

McLean, VA 22101

Phone: 703-790-5750

National Bureau of Standards

Mr. Jim Pielert

Secretariat

Committee 9, Regulatory Use

National Bureau of Standards

Rm. B168 , Bldg. 226

Washington, D. C. 20234

Phone: 301-921-3146

(Mr. Pat Cooke)

Phone: 301-921-2776

E-24
NBS-114A (REV. 2-80

U.S. DEF r. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See i nstructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 80-2111-11

2. Performing Organ. Report No.l 3. Publication Date

October 1980

4. TITLE AND SUBTITLE

Review and Refinement of ATC 3-06 Tentative Seismic Provisions:

Report of the Joint Committee

5. AUTHOR(S)

E. V. Leyendecker, Editor and James R. Harris, Editor

6. PERFORMING ORGANIZATION (If joint or other than N BS. see in struction s) 7. Contract/Grant No. NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE 8. Type of Report & Period Covered

WASHINGTON, D.C. 20234

Final

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State. ZIP)

Federal Emergency Management Agency

Washington, D.C. 20472

10.

SUPPLEMENTARY NOTES

I

j Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here)

The Tentative Provisions for the Development of Seismic Regulations for

Buildings were developed by the Applied Technology Council to present,

in one comprehensive document, current state-of-knowledge pertaining to

seismic engineering of buildings. The Tentative Provisions are in the

process of being assessed by the building community. This report is

one of a series of reports that documents the deliberations of a group

of professionals jointly selected by the Building Seismic Safety Council

and the National Bureau of Standards and charged with reviewing the

Tentative Provisions prior to the conduct of trial designs. The group

is divided into nine technical committees, each of which focused on a particular portion of the Tentative Provisions . The nine committees

proposed recommendations for change to the parent group, the Joint

Committee, through a Coordinating Committee. The Coordinating Committee

made some modifications to the technical committees' recommendations to

ensure consistency among the recommendations. This report documents the

actions of the Joint Committee on the 198 recommendations for change

that were presented to it. The first part of the report is a summary of

the results, and the appendices contain the full documentation for each

recommended change. The actions of each of the nine technical committees

is dnmmpntpd in a apparato yopnrf12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s) Building; building codes; building design; earthquakes; engineering;

standards; structural engineering

13. AVAILABILITY 14. NO. OF

[_^J Unlimited

PRINTED PAGES

j

j For Official Distribution. Do Not Release to NTIS 329

1 Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402. 15. Price

Qj Order From National Technical Information Service (NTIS), Springfield, VA. 22161

USCOMM-OC S043-P90
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