Reference Publl * cations ' ' A 11 ID 4 3bDb^fi

NBSIR 78-1549

* Plan for the Assessment and

Implementation of Seismic

Design Provisions for Buildings

Charles G. Culver

Robert E. Chapman

Patrick W. Cooke

Bruce R. Ellingwood

S. George Fattal James R. Harris

Edgar V. Leyendecker

Center for Building Technology

National Engineering Laboratory

National Bureau of Standards

Washington, D.C. 20234

November 1978

QC100

Sponsored by:

The National Science Foundation

Washington, D.C. 20550

Mitml imi i* MAY 1 4 m

NBSIR 78-1549

i f

1 PLAN FOR THE ASSESSMENT AND

IMPLEMENTATION OF SEISMIC

DESIGN PROVISIONS FOR BUILDINGS

Charles G. Culver

Robert E. Chapman

Patrick W. Cooke

Bruce R. Ellingwood

S. George Fattal James R. Harris

Edgar V. Leyendecker

Center for Building Technology

National Engineering Laboratory

National Bureau of Standards

Washington, D C. 20234

November 1978

Sponsored by:

The National Science Foundation

Washington, D.C. 20550

U.S. DEPARTMENT OF COMMERCE, Juanita M. Kreps, Secretary

Dr. Sidney Harman, Under Secretary

Jordan J. Baruch, Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director
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ABSTRACT

This plan deals with the assessment and implementation of tentative

seismic design provisions developed by the Applied Technology Council

as part of the Cooperative Federal Program in Building Practices for

Disaster Mitigation of the National Science Foundation and the

National Bureau of Standards. The plan was prepared based on comments

received from a broad spectrum of representatives of the building

community. The National Bureau of Standards invited participation

from a broad spectrum of interests to help develop the plan. Trade

associations, industry groups, progessional organizations, the model

code organizations, standards organizations and Federal agencies were

included; groups with national representation rather than regional or

local interest were selected.

The plan includes four phases (1) Review and Refine Tentative Provisions,

(2) Trial Designs and Impact Assessment, (3) Consideration and Adoption

of Provisions, and (4) Assistance to Facilitate implementation. It can form the basis for the assessment and implementation of the tentative

seismic design provisions. As the effort proceeds, it may be necessary

to refine the plan. Additional details will need to be specified for

the individual tasks. These will be influenced by the procedure adopted

to carry out the activities.

Key Words: Assessment; building codes; building design; disaster mitigati

earthquakes; engineering; implementation, standards
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TABLE OF CONTENTS

Page

PREFACE 1

BACKGROUND 3

PROGRAM OBJECTIVES 4

GENERAL CONSIDERATIONS 4

ACTIVITIES AND PARTICIPANTS 5

TIME SCHEDULE 6

APPENDIX 12

iv

PREFACE

This plan deals with the assessment and implementation of tentative

seismic design provisions prepared by the Applied Technology Council as part of the Cooperative Federal Program in Building Practices for Disaster Mitigation of the National Science Foundation and the National Bureau

of Standards. The plan was prepared based on comments received from

a broad spectrum of representati ves of the building community. The

National Bureau of Standards invited participation from a broad spectrum

of interests to help develop the plan. Trade associations, industry

groups, professional organizations, the model code organizations,

standards organizations and Federal agencies were included; groups with

national representation rather than regional or local interests were

selected.

As a first step, a meeting was held at NBS on April 21, 1978, with some 30 invited organizations (Figure 1). A list of the participants

is included in the plan. Representatives from forty organizations

attended the April 21 meeting and provided their initial views on required elements in the plan. Twenty-nine of these organizations

provided additional written comments following the meeting.

The main points raised were:

Need for consensus agreement on the provisions before

adoption for regulatory use.

Need to evaluate the technical accuracy and correctness

of the provisions prior to assessing their economic inpact.

Carry out trial designs involving comparison of the provisions

with existing requirements.

Involve professional and trade organizations directly in

assessment activities.

Provide a mechanism to revise the provisions, if necessary,

following the trial designs.

Provide for continual feedback and response to participant 's comments throughout the assessment effort.

Many of the organizations volunteered to participate in carrying out the

assessment program.

A first draft plan was prepared by NBS staff based on this material.

The draft was forwarded to all participants on July 20 for review and

additional comments. Sixteen organizations provided comments. There

was general agreement on the overall structure of the assessment effort;

the plan reflects this. The comments were used to prepare the final

1
plan. Individual responses were provided to each participant indicating

how their comments were handled.

This plan can form the basis for the assessment and implementation

of the tentative seismic design provisions. As the effort proceeds, it

may be necessary to refine the plan. Additional details will need to be

specified for the individual tasks. These will be influenced by the

procedure adopted to carry out the activities.

2
BACKGROUND

In 1974, the National Science Foundation and the National Bureau of

Standards initiated a program to develop improved seismic design provisions for buildings. Damage resulting from the 1971 San Fernando

earthquake demonstrated the need for improved provisions. Design

professionals, building officials and researchers recommended that model

code provisions and a commentary be prepared on a top priority basis to

bring the minimum level of practice in seismic design and construction

into line with the state of knowledge.

The NSF/NBS program was carried out working with the Applied Technology

Council, a group affiliated with the Structural Engineers Association of

California. A multidisciplinary team of some 85 nationally recognized

experts in earthquake engineering developed the provisions. During the course of the project, two drafts of the design provisions were prepared

for public review by individuals and organizations. In each case approximately 400 copies were distributed for review. The final provisions

are included in the report. Tentative Provisions for the Development of

Seismic Regulations for Buildings, NBS Special Publication 510, June

1978.

The purpose of the NSF/NBS program was to develop comprehensive seismic

design provisions for buildings suitable for use throughout the United

States. It was intended that the provisions be available for consideration by model codes and standards organizations and regulatory groups at

the Federal, State and local level. As the program evolved, it became

clear that a number of issues needed to be addressed prior to adoption

of these provisions. These included: (1) determination of the technical

viability, consistency and completeness of the tentative provisions,

(2) determination of the hazard reduction achieved by the provisions

and the associated costs, and (3) evaluation of differences between

the provisions and requirements in existing codes and standards. NSF

and NBS initiated an effort in 1978 to develop a plan to address these

issues. The plan in this report resulted from this work; it defines

activities and identifies participants.

The Earthquake Hazards Reduction Act of 1977 (PL 95-124) has as its

purpose the establishment of an effective earthquake hazards reduction

program. The objectives of the program include, "the development,

publication and promotion, in conjunction with State and local officials

and professional organizations, of model codes and other means to coor- dinate information about the seismic risk...." It is anticipated that

this assessment and implementation plan will be used in connection with

the activities relating to seismic design and construction standards

included in the national earthquake hazards reduction program developed

in response to the legislation.

3
PROGRAM OBJECTIVES

The objectives of the program covered by this plan for the assessment

and implementation of seismic design provisions for buildings are to:

1. Refine the technical details of the provisions.

2. Provide a detailed assessment of the viability and impact

of the design provisions.

3. Revise the provisions, as necessary, based on results of the

assessemnt.

4. Submit the provisions to appropriate groups for adoption.

5. Develop necessary mechanisms to facilitate implementation and

enforcement.

GENERAL CONSIDERATIONS

The National Earthquake Hazards Reduction Program prepared by the

President in response to the Earthquake Hazards Reduction act of 1977

recognized the importance of codes and standards in reducing earthquake

hazards. The program emphasized non-Federal participation including

State and local government, business, industry, the design professions,

the research community and the public. The program and the responsibilities defined in the President's plan provide the framework for

carrying out the assessment and implemenation effort. The plan also

notes that enthusiasm, expertise, and willingness to work are required

to make the program effective; contributions in this regard through

cost sharing in the commitment of resources involving time and expertise

are necessary to carry out the activities of the plan.

The President's plan assigns responsibility for developing seismic design

standards for Federal building construction to an Interagency Committee

on Seismic Safety in Construction. The committee will be composed of

representati ves of all Federal agencies significantly engaged in con- struction, the financing of construction, or related activities. Recognizing that construction undertaken by the private sector is regulated by

State and local government, the plan provides for Federal cooperation

in developing and improving codes and standards. The National Bureau of

Standards is assigned responsibility for the development of seismic

design and construction standards for consideration and subsequent

application in Federal construction, and the responsibility for

encouraging adoption of improved seismic provisions in State and local

building codes. NBS, therefore, will serve as the focal point for the

assessment effort and will be responsible for overall coordination and

management. NBS will also provide technical input and provide the

required continuity between the various phases of the work described

in subsequent sections of the plan.

4
A Codes and Standards Implementation Committee composed of representatives from organizations directly involved in implementing codes and

standards will be formed by NBS with the assistance of the Consultative

Council of the National Institute of Building Sciences. The Implementation Committee will work directly with NBS providing technical input

and comments as the work proceeds, particularly as it relates to final

implementation of the provisions. The committee members will also

provide direct liaison with their respective organizations. The

membership of the committee is given in Figure 2.

The assessment effort will include broad based participation. The Interagency Committee on Seismic Safety in Construction will be involved to

insure coordination of work on Federal standards with that for codes and

standards for the private sector. Organizations from the private sector

will be involved in each phase of the effort. Organizations with particular technical expertise appropriate for each task in the overall program are identified in subsequent sections of this plan. Specific responsibilities and lead roles will be defined through discussions with these

organizations as the plan evolves and the assessment effort gets underway.

Recognizing the significant effort involved in developing the provisions

included in the report. Tentative Provisions for the Development of

Seismic Regulations for Buildings , these provisions and the review

comments received on the previous drafts of that report will serve as the basis for the assessment. Where additional research results are available in a form amenable to use in design practice, these will be

included, as appropriate, as revisions are made to the provisions.

Results from on-going research in earthquake engineering and seismology

will be considered in the continuing efforts to develop improved seismic

design provisions.

The time schedules for the tasks in the assessment were developed on the

basis of initial estimates of the work involved. This schedule relates

only to the work involved with the tentative provisions. It does not

reflect subsequent efforts to continually improve provisions as new research results become available. Consideration, however, was given to

the time schedule established in the President's plan for the other

activities related to implementation of the design provisions in codes

and standards. Accordingly, results from the assessment effort should

be available for consideration as the national program develops.

ACTIVITIES AND PARTICIPANTS

The assessment and implementation effort will involve a multi -phase

effort. The four phases and the tasks required in each phase are shown

in Figure 3. Detailed descriptions of the objectives and activities

involved in each Task are included in the Appendix.

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TIME SCHEDULE

A time schedule for the plan is given in Figure 4. Where possible,

the tasks were scheduled concurrently. In Phase I, for example, all

four tasks can be carried on simultaneously. The experimental design

in Phase II, Task 1 can be carried on at the same time. Determination

of the impacts of the provisions in Task 4 of Phase II can begin prior

to completing Task 3 as the data from the trial designs becomes

available.

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ORGANIZATIONS PARTICIPATING IN PLANNING EFFORT

American Concrete Institute

American Institute of Architects

American Institute of Steel Construction

American Insurance Association

American Iron and Steel Institute

American National Standards Institute

American Plywood Association

American Society of Civil Engineers

American Society of Heating, Refrigerating and Air Conditioning Engineers

American Society of Mechanical Engineers

American Society of Plumbing Engineers

Applied Technology Council

Associated General Contractors of America

Association of Engineering Geologists

Association of Major City Building Officials

Brick Institute of America

Building Officials and Code Administrators International, Inc.

Earthquake Engineering Research Institute

International Conference of Building Officials, Inc.

Masonry Institute of America

National Academy of Code Administration

National Concrete Masonry Association

National Conference of States on Building Codes and Standards, Inc.

National Forest Products Association

National Institute of Building Sciences

Portland Cement Association

Post-Tensioning Institute

Prestressed Concrete Institute

Southern Building Code Congress International, Inc.

Structural Engineers Association of California

Federal Agencies

Department of the Air Force

Department of the Army

Department of Energy

Department of Health, Education, and Welfare

Department of Housing and Urban Development

Department of the Navy

Federal Disaster Assistance Administration

General Services Administration

Nuclear Regulatory Commission

U.S. Coast Guard

U.S. Geological Survey

Veterans Administration

FIGURE 1

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CODES AND STANDARDS IMPLEMENTATON COMMITTEE MEMBERSHIP

American

American

American

American

American

American

American

American

American

American

American

American

Concrete Institute

Institute of Architects

Institute of Steel Construction

Institute of Timber Construction

Insurance Association

Iron and Steel Institute

National Standards Institute

Plywood Association

Society of Civil Engineers

Society of Heating, Refrigerating and Air Conditioning Engineers

Society of Mechanical Engineers

Society of Plumbing Engineers

Association of Major City Building Officials

Brick Institute of America

Building Officials and Code Administrators International, Inc.

Interagency Committee on Seismic Safety in Construction

International Conference of Building Officials, Inc.

National Concrete Masonry Association

National Conference of States on Building Codes and Standards, Inc.

National Forest Products Association

National Institute of Building Sciences

Portland Cement Association

Southern Building Code Congress International, Inc.

Structural Engineers Association of California

FIGURE 2

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ASSESSMENT AND IMPLEMENTATION ACTIVITIES

PHASE I - Review and Refine Tentative Provisions

Objective - Resolve questions on technical basis of

provisions and refine provisions.

Task 1 Resolve corranents on structural design

la

lb - lc

requirements and design procedures

Risk Maps

Structural Design

Soil Structure Interaction and Foundations

Task 2

2a - 2b - 2c - 2d -

Resolve comments on materials requirements

Concrete

Masonry

Steel

Wood

Task 3 Resolve comments on architectural, mechanical

and electrical systems and components

Task 4 Resolve conments on the regulatory use of the

provisions

PHASE II - Trial Designs and Impact Assessment

Objective - Establish technical viability of provisions

and develop data on economic impact.

Task 1 Design of Experiment

Task 2 Trial Designs

Task 3 Determine Impact

Task 4 Evaluate Adequacy of Provisions

PHASE III - Consideration and Adoption of Provisions

Objective - Achieve consideration of provisions for

adoption by codes and standards organizations.

Task 1 Adoption by standards organizations

Task 2 Adoption by model codes

FIGURE 3

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PHASE IV - Assistance to Facilitate Implementation and Enforcement

Objective

Task 1

Task 2

Task 3

Task 4

Provide educational training, organizational

structure and technical assistance needed for

implementation.

Education and Training

Technical Support for Interpretation Services

Develop Guidelines for Evaluation and Inspection

Laboratory Accreditation Criteria

FIGURE 3 - Cont.

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TIME SCHEUDLE

YEAR 1 YEAR 2 YEAR 3

Phase I - Review & Refine Tentative Provisions

Task 1 - Resolve comments on structural

design requirements & design

procedures

Task 2 - Resolve comments on materials

requirements

Task 3 - Resolve comments on architectural,

mechanical & electrical systems

and components

Task 4 - Resolve comments on the regulatory

use of the provisions

Phase II - Trial Designs & Impact Assessment

Task 1 - Design of Experiment

Task 2 - Trial Designs

I

Task 3 - Determine Impact

Task 4 - Evaluate Adequacy of Provisions

Phase III - Consideration & Adoption of Provisions

Task 1 - Adoption by standards organizations

Task 2 - Adoption by model codes

Phase IV - Assistance to Facilitate Implementation and Enforcement

Task 1 - Education and Training

Task 2 - Technical Support for Interpretation

Services

Task 3 - Develop Guidelines for Evaluation and

Inspection

\

Task 4 - Laboratory Accreditation Criteria

FIGURE 4

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APPENDIX

PHASE I - Review and Refine Tentative Provisions

Comments received on the two previous drafts of the tentative provisions

from organizations and individuals who were also involved in developing

the plan to implement seismic regulations for buildings indicate that

differences of opinion exist regarding many of the technical provisions.

Many of the provisions appear to be arbitrary and not substantiated by

sufficient commentary. Other provisions may not reflect recent research

findings fairly. Comments received during development of this plan

indicate that these differences of opinion still exist. Particular

problems exist in the materials area. The basic design philosophy with

respect to the masonry provisions, for example, has been challenged. The

importance of reaching consensus on the provisions prior to their adoption has been emphasized by all participants. A number of unresolved

issues remain. The objective of the first phase of the assessment is

to resolve these issues to the maximum extent possible so that it will

be possible to reach consensus agreements in Phase III. Resolution of

these issues is the first step toward consensus agreement on the

provisions. It is important that these issues be resolved prior to

carrying out trial designs in Phase II in order to maximize the benefits

from such studies.

The Phase I review will focus primarily on comments received on the two

previous drafts of the tentative provisions. The purposes of this review

will be: (1) to insure that the trial designs and benefit-cost analysis

in Phase II are made with a set of provisions which all affected parties

are reasonably satisfied with, and (2) to insure that the provisions are written in enforceable language that can be easily interpreted by

designers and code officials. It should be emphasized that Phase I will

be limited to an examination and refinement of the existing provisions

with possible deletion of some provisions as described subsequently. It

is possible that a basic reassessment may take place following Phase II when there will be sufficient design and cost information available

to make a reassessment more meaningful.

Committees will be formed from organizations substantially affected by

the tentative design provisions. These committees will be invited to

review and resolve the comments on the tentative provisions with a representative of ATC. In each case, a positive resolution from the

committee concerned with review of a particular provision and comment

will be required, i.e., (a) the comment. . .has merit and the provisions

will be changed accordingly, or (b) the comment has been considered

and has not been incorporated for the following reason (state reason).

Where questions arise regarding the adequacy of the technical basis

of a provision, the ATC representative will provide the basis used in

the development of the Tentative Provisions.

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Every attempt will be made to achieve consensus on individual provisions

Where differences of opinion exist regarding the details of a provision

and interpretation of the technical data, majority rule will be used

to establish the provision to be used in the assessment. Complete agree

ment obviously will not be possible in every instance. It should be

recognized that subsequent tasks in the assessment, particularly Task

2 of Phase II, will provide useful data in this regard. Since these

data will affect the final provisions recommended to codes and standards

groups in Phase III, complete consensus is not necessary in Phase I. This procedure will assure each affected group that their comments on the provisions definitely have received consideration.

If a majority of the committee members involved in reviewing the particular provision do not concur in the adequacy of the technical basis,

and deletion of the provision in question will not disrupt other interrelated provisions, the provision will not be included in the assessment

Should a committee feel that a large portion of the provisions or

a provision that is significantly interrelated with others ought to

be deleted, it is possible that Phase II would proceed based upon a subset of the original provisions. In any instance, it is probable

that Phase II would proceed in order to provide additional information

to aid in future resolution of related issues.

This procedure should facilitate the consensus process required for

implementation in Phase III. It is anticipated that the Codes and Standards Implementation Committee will provide technical input to this

phase. Their early involvement at this stage together with results

from the trial designs will provide the background for evaluation of

the adequacy of the provisions in Task 4, Phase II.

Phase I will be accomplished through the following four tasks. The

organizations involved in each task are listed. It is anticipated that

the Applied Technology Council representative will be from the task

committee involved in developing the orginal provisions under study

by the committee.

Task 1 - Resolve Comments on Structural Design Requirements and Design

Procedures

This task has three components: seismic risk maps, bases for structural

design, and soi 1 -structure interaction and foundations; committees will

be formed with responsibility for each component. The committee to

evaluate risk maps will consider, among other things, possible variances

in the risk maps: the maps which were used as a basis for the current

provisions were developed using a new technique which is still being

evaluated by seismologists. The conrni ttee will include representatives

from:

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o American Society of Civil Engineers

° Association of Engineering Geologists

0 Interagency Committee on Seismic Safety in Construction

° Seismological Society of America

° Structural Engineers Association of California

° U.S. Geological Survey

° Applied Technology Council

The membership of the committee to evaluate the bases for structural

design will consider R and C d factors, strength and deformation criteria,

classification of buildings, and analytical procedures, etc. It will

include representatives from:

° American National Standards Institute

° American Society of Civil Engineers

° Interagency Committee on Seismic Safety in Construction

° Representation from concrete industry

° Representation from masonry industry

° Representation from prestressed concrete industry

° Representation from steel industry

° Representation from timber industry

° Structural Engineers Association of California

° Applied Technology Council

Each material group will have a representative who will also be involved

in Task 2.

The membership of the committee to evaluate the provisions for

foundations and soil structure interaction will include:

° American Society of Foundation Engineers

° American Society of Civil Engineers

° Interagency Committee on Seismic Safety in Construction

° Structural Engineers Association of California

° Applied Technology Council

Task 2 - Resolve Comments on Materials Requirements

Four committees will be formed to evaluate the comments received on the

provisions that pertain directly to materials. Membership on the group

to evaluate the concrete provisons will include representati ves from:

° American Concrete Institute

° Portland Cement Association

° Post-Tensioning Institute

° Prestressed Concrete Institute

° Applied Technology Council

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The masonry provisions will be considered by representatives of:

° American Concrete Institute

° American National Standards Institute

° American Society of Civil Engineers

° Brick Institute of America

° Masonry Institute of America

° National Concrete Masonry Association

° Applied Technology Council

The group to consider the steel provisions will include representatives

from:

° American Institute of Steel Construction

° American Iron and Steel Institute

° Metal Building Manufacturers Association

° Applied Technology Council

Provisions for wood structures will be considered by representatives

of the following:

° American Plywood Association

° Forest Products Laboratory

° National Forest Products Association

° Applied Technology Council

Task 3 - Resolve Comments on Architectural, Mechanical and

Electrical Components and Systems

These provisions will be reviewed by a committee which will include

representatives of the following groups:

° American Institute of Architects

° American Society of Heating, Refrigerating and

Air Conditioning Engineers

° American Society of Mechanical Engineers

° American Society of Plumbing Engineers

° Interagency Committee on Seismic Safety in Construction

° National Elevator Industry, Inc.

° National Fire Protection Association

° Applied Technology Council

There is a paucity of information regarding the performance of me chani cal and electrical systems during earthquakes. Nevertheless, damage to

these systems is a major source of earthquake damage. Concern has been

expressed that satisfaction of certain provisions is not possible with

existing technology. Other provisions impose burdens of certification

of equipment upon manufacturers that may be impractical and incompatible

with present manufacturing processes. Particular attention will be paid

during the review to the practicality of the provisions for mechanical

and electrical equipment.

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Task 4 - Resolve Comments on the Regulatory Use of the Provisions

The purpose of this task is to review the provisions for enforceability

and ease of interpretation by designers and building officials. The

membership of the committee to carry out this task will include representatives of the following organizations:

° American Insurance Association

° Associated General Contractors of America

° Assocation of Major City Building Officials

° Building Officials and Code Administrators International

° Building Owners and Managers Association

° Construction Research Council

° International Association of Plumbing and Mechanical Officials

° International Conference of Building Officials

° National Conference of States on Building Codes and Standards,

Inc.

° Southern Building Code Congress International

° Applied Technology Council

The comments to be resolved include:

(1) Comments on the administrative requirements and procedures

established, particularly in Chapters 1 and 13, and

(2) Comments about the enforceability of the technical provisions.

Representatives of the model code organizations have made particularly

strong comments about Chapter 13, "Systematic Abatement of Seismic

Hazards in Existing Buildings." It is not expected that the question

of the feasibility of code adoption of such a large scale retroactive

program would be resolved by this committee. The focus of this task

committee is to resolve questions of wording, procedures, and clarity,

not organization, programs or philosophy.

The tasks involved in Phase I cannot be carried out independently;

interaction between the committees is required. Determination of the

seismic force levels involved in Task 1 and the materials performance

in Task 2 are an integral part of good design. Similarly, practicing

professionals (architects and engineers) will need to be consulted in

Task 4. The four tasks will therefore be closely coordinated by NBS.

It is anticipated that the four tasks in Phase I can be completed

simultaneously in 6 months from the start of the project.

PHASE II - Trial Designs and Impact Assessment

This phase of the plan focuses on establishing a viable framework for

carrying out trial designs and for interpreting and assessing their

economic impacts on the construction industry and the general public.

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The scope of this phase will be limited to the provisions dealing with

new construction. It has as its technical base the revised set of seismic

design provisions resulting from the Phase I effort. Engineering expertise, economic theory and statistical methods will be utilized in order

to maximize the content and quality of the information produced in

the trial design case studies.

The basic objective of this phase is to establish the technical

viability of the provisions and to develop and analyze data on the

economic impacts of the seismic design provisions. In addition, this

phase will facilitate the revision of specific provisions which may

be too stringent or too lax. As such, it will permit the requirements

of the Earthquake Hazards Reduction Act of 1977 (PL95-124) to be met

in the most cost-effective way.

Task 1 - Design of Experiment

The experiment of conducting trial design must be carefully designed to assure that the results can be extrapolated reliably beyond the specific

examples in order to evalute the technical and economic implications of

the seismic design provisions. Given practical limits on funding, only

a limited number of trial designs can be conducted, so special consideration must be given to the way in which sites and building types

are selected. Ideally, construction market information should be

collected and statistical methods utilized to insure that the trial

designs provide the data needed to determine measures of the impacts

of the provisions. In particular, the two following criteria should

be satisfied:

(1) Those cities selected for the trial designs (which might be

hypothetical average cities) should be representative of the

variations in seismic risk across the United States and

(2) Those building types analyzed should represent the type of new construction most likely to be substantially affected by the

new seismic provisons.

Several factors appear to be of importance in selecting the candidate

sites. These factors are:

(1) Seismic risk

(2) Population density

(3) Number of existing buildings

(4) Value of new construction, and

(5) Presence or lack of existing seismic provisions in building

codes

Careful consideration must be given to the availability of data which

would facilitate the extropolation of cost studies from individual

buildings to the entire construction market. This would include effects

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on the labor and materials markets. (Examples of such information would

be input-output or econometric models.) Consideration should also be

given to the availability of data on benefits expected to accrue as

a result of improved seismic resistant design.

Criteria which are useful in identifying candidate building types

i nclude:

(1) Size (area and height)

(2) Use (occupancy)

(3) Configuration

(4) Structural materials and systems

(5) Foundation materials and systems

(6) Non-structural walls and partitions, and

(7) Mechanical and electrical equipment and systems (particularly

their supports and attachments).

The National Bureau of Standards with input from the Codes and Standards

Implementation Committee, should be responsible for designing the

experiment, specifying where and how many trial designs are to be

carried out, and insuring that the results of the trial design task

provide the material necessary to assess the impacts of the seismic

design provisions. It is estimated that the experimental design can

be completed within six months.

Task 2 - Trial Designs

The objective of this task is to develop, through trial designs of

representative buildings, a quantitative basis for evaluating the

practical impact of the tentative provisions, together with the revisions

and refinements introduced in Phase I.

The three major activities envisioned for this task are:

(1) Planning and coordination of work

(2) Conduct the trial designs, and

(3) Collection of cost information

Planning and coordination will involve selection of consulting firms,

drafting the work statements based on Task 1, letting the actual

contracts, and assuming supervisory and monitoring responsibilities

until completion of contractual obligations. Organizations with the

potential for planning and coordinating this work include: American

Society of Civil Engineers, American Institute of Architects, National

Society of Professional Engineers, American Consulting Engineers Council,

and the National Bureau of Standards. The Applied Technology Council

will provide interpretation of the provisions during conduct of the

trial designs.

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The consultant will prepare two designs for the same structure. One of

the designs will be in accordance with the ATC 3 provisions as modified

in Phase I. The other design will be based on existing building regulations as identified in Task 1. In addition, the consultant will supply

comparative data between the two designs, including a quantitative

estimate of the differences in design costs and an itemized list com- paring the substantive differences between the two sets of provisions.

It is possible that Task 1 will specify that the consultant will also

supply construction cost estimates. If so, the consultant will be

asked to provide comparative cost estimates of construction on the basis

of actual bids for the job obtained from several contractors. In order

to control variations in estimated construction costs and materials usage

among the consultants developing the trial designs, a single cost

accounting firm will prepare detailed sets of comparative construction

cost estimates. Construction inspection costs will also be estimated.

Costs estimates will also be obtained for plan review and inspection

in the enforcement by building code officials.

The information acquired from the trial designs will be consolidated and

used as a basis to determine the impact of the seismic provisions on the building community (subsequent Task 3) and to assist in the decision

making process (subsequent Task 4).

It is estimated that the task of trial designs can be completed 12 months

after initiation. It can corrcnence at 8 months into Year 1.

Task 3 - Determine Impacts

The determination of the impacts associated with the seismic design

provisions developed in Phase I are threefold. The first level of

analysis relates to the impact on costs for a given building in a given

location. The second level of analysis refers to the impact that

the use of the seismic design provisions has on the construction

industry. The second level is more complicated than the first because

individual impacts may vary with building type, location, and/or current

seismic codes. The extrapolation from the trial designs to the impacts

on cities, regions and the nation becomes increasingly more difficult.

Certain elements of the construction industry or certain geographic

areas may be more strongly affected than others. These impacts represent

a real cost which cannot be ignored and which must be carefully weighed

against any benefits to society or to competitors. The third level of

analysis relates to any changes in benefits and costs which accrue to

society as a result of the seismic design provisions. A description of

each level of analysis and its impacts is summarized below.

Level 1

Two sets of cost calculations will be available as a result of the trial

design case studies. Using this information, the comparative impact of

the seismic design provisions in each of the following areas will be

determined:

19
(1) Initial capital cost of the project

(2) Type and amount of building materials

(3) Type and amount of labor

(4) Physical characteristics of the building

(5) Insurance costs, and

(6) Regulatory costs

Level 2

The results from the level 1 analysis will produce a set of micro impacts

on the construction industry. To see how all of these micro impacts will

affect the construction industry, it will be necessary to divide the

industry into sectors and the nation into regions. The sectors which are

of particular importance and which will be examined in detail are:

(1) Building materials producers

(2) Building materials suppliers

(3) Building equipment suppliers

(4) Building regulatory authorities

(5) Architectural /Engi neering design firms, and

(6) Labor

Level 3

In level 3, as detailed a benefit-cost analysis as possible will be

performed. The results of the benefit-cost analysis will indicate if

society is better or worse off by going to an increased level of seismic

safety outlined in the seismic design provisions. The costs of the

seismic design provisions will be based on detailed summaries of the

results of the first two levels of analysis. Economic criteria and

published statistics will then be used to estimate those benefits

accruing to society from the use of the seismic design provisions.

Particular emphasis will be placed on estimating deaths and injuries

and property damages averted. If related benefits or costs which might

accrue to building owners, occupants, or society in general, due to use of these provisions can be identified, they will be considered.

Once societal benefits have been estimated, it will then be necessary to

examine how these benefits are distributed over individual buildings.

This approach should point out whether or not the seismic design

provisions are economically efficient from a benefit-cost viewpoint

for a particular building type. This approach should also facilitate

the identification of specific provisions, if any, which are likely

candidates for revision.

The National Bureau of Standards with input from the implementation

committee will be responsible for this task. Nationally recognized

management consulting firms will participate with NBS in this activity.

Nine months will be required for this task.

20
Task 4 - Evaluate Adequacy of Provisions

This task is an evaluation of the results of the economic impact study

based on the refined provisions determined in Phase I. The purpose of

the evaluation is to determine if additional refinements are necessary

prior to proceeding to the implementation of Phase III. Three basic

outcomes are considered possible. The first of these is to proceed

directly to Phase III. The second is that additional refinement of

the provisions is required in order to lessen the economic impact.

This will require repeating Phases I and II although on a much smaller

scale than the original phases. The third option is a complete reassessment of the seismic design provisions.

Responsibility for this evaluation should rest with the Codes and

Standards Implementation Committee. This committee should establish

criteria for determining the adequacy of the provisions and develop

procedures for evaluating the provisions based on the assessment data

obtained.

PHASE III - Consideration and Adoption of Improved Provisions

For Seismic Resistant Design

The objective of this phase is to achieve adoption of the provisions in

national standards and model codes. It is important that this activity

be carried out in a coordinated fashion. There are several factors

to consider in achieving suitable coordination. There are two tasks

in this phase:

° Task 1 - Adoption of the provisions by national standards

organizations

° Task 2 - Adoption of the provisions by model codes organizations

These two tasks will be discussed simultaneously.

It is apparent that the new seismic provisions impinge upon a large

number of standards. Thus, the activities of many different organizations must be coordinated in order to achieve the objective. The

work of Phase III will be carried out by the implementation committee.

For these tasks the committee assumes the additional role of carrying

out the work. Note that the implementation committee does not include

representation from city and State building code authorities. Although

the entire objective of PL 95-124, with regard to buildings, hinges

upon achieving improved provisions in legal codes, this plan does

not include the coordination of activities at that level. There are

several reasons for this: the scale of this plan is necessarily

national, and once developed, the local activities will follow; changes

in local codes normally follow changes in model codes; there are

21
so many different local codes that the national standards and model

codes interests on the advisory committee would be overwhelmed; and

there are several organizations included that effectively represent

local interests.

The activities can be separated into four functions:

(1) Planning and scheduling their activities (with respect to the

provisions) around those of each standard and code organization. This could feasibly include recommending the creation

of a new standard where none exists.

(2) Placing the appropriate new provisions on the agenda of each

individual organization and advocating their consideration.

(3) Reporting back to the entire committee on what actions each

organization is taking with regard to the new provisions.

(4) Consideration of and decision on what new actions are to be

taken (if any) as a result of rejection or modification

of the new provisions by any organization.

There are two priorties that the implementation committee would be

expected to observe in planning and scheduling their activities. First,

it would be expected that the new provisions be considered by national

standards before they are considered by the model codes. The rationale

behind this is that many of the national standards arrive at decisions

in accordance with the rules of ANSI governing voluntary consensus

standards for balanced representation among committee membership, due

process for notification, balloting and resolution of dissent, and

for definition of substantial agreement, whereas none of the model

code organizations follow the complete set of ANSI rules.

The second priority for scheduling is that among the standards for

structural design, ANSI A 58 should lead and the several standards

for the design of concrete, steel, masonry, and wood structures should

follow. It is clear that there is only one significant standard

for the loads for which structures are to be designed and that there

are several for determining the strength and stiffness of buildings

and components and for the detailed rules of construction, each peculiar

to a specific building material. Thus, if A 58 reaches a decision

first, then all the materials standards, will be assured of a common

basis of reference for loads. In addition, A 58 is structured to

achieve consensus according to ANSI, whereas several of the materials

standards are not.

The fourth activity listed in this phase, that of deciding on new actions to take as a result of unilateral rejection or modification

of the new provisions by any organization is important because of

the nature of the provisions developed by ATC. The consideration of

22
inelastic behavior in resisting seismic loads requires that provisions

for the effect of load on a structure and the strength and stiffness

of that structure be coordinated in a fashion that philosophies of

elastic design have not required. For this reason actions of individual

standards organizations cannot be viewed as independent activities,

and it may be necessary for the implementation committee to recommend

revised provisions, or the development of revised provisions, to one organization as the result of the action of another organization.

PHASE IV - Assistance to Facilitate Implementation And Enforcement

This phase of the plan recognizes the burden the provisions will place

on the building regulatory process as well as the design professionals

and other members of the building community. It provides for information

and technical assistance to the States and other jurisdictions in the

adoption, implementation and ongoing enforcement of the seismic design

provisions. Also, the emphasis of the standards has been towards a broader performance orientation. Performance standards have the desired

effect of providing for end results without specifying the material,

component or system thus allowing maximum freedom to provide innovative

solutions. However, to the extent that the standards are performance

oriented, they further increase the complexity of interpretation,

evaluation and enforcement for both design professionals and regulatory

officials. The proposed tasks outlined in this phase are designed

to facilitate the effective implementation of the standards in a coordinated manner.

The primary objectives of this phase of the plan will be to provide the

necessary education and training, organizational structure and technical

and professional assistance, so that buildings can be successfully

designed and evaluated in compliance with the standards. In addition,

a secondary objective will be to track the implementation progress by

States and local regulatory agencies and to assess the methodology

and completeness of State or local implementation.

Task 1 - Education and Training

It will be necessary to educate and train members of the building

community for successful implementation of the seismic design provisions.

The training project will plan, develop and deliver training courses for

design professionals, builders, building regulatory officials, industry

representatives and other interested members of the building community.

Training materials and prototype courses will be developed for the varied

segments of the building community and instructors will be selected,

trained and certified. Pilot sessions will be conducted to judge the

adequacy of course materials for each course of training. Instruction

will be carried out in numerous locations. The following organizations

may be expected to play a role in this task:

23
° American Society of Civil Engineers

° American Institute of Architects

° American Society of Mechanical Engineers

° American Society of Heating, Refrigeration and

Air Conditioning Engineers

° Building Officials and Code Admi nstrators International

° International Conference of Building Officials

° National Society of Professional Engineers

° National Conference of States on Building Codes and Standards,

Inc.

° National Academy of Code Administration

° Southern Building Code Congress International.

Other professional organizations including regional organizations such

as the Structural Engineers Association of California are expected to

play an important role in this task. Materials organizations should

also contribute to the development and dissemination of educational

i nformation.

Task 2 - Technical Support for Interpretation Services

Implementation of the seismic design provisions will generate many

questions from the building regulatory community concerning interpretation of its provisions. In some cases it will be necessary to

provide technical support for the interpretation services of existing

standards organizations when questions arise which are not of a routine

nature.

Questions of a technical nature on the seismic design provisions will

arise which cannot be routinely answered with the existing level of

knowledge among code compliance officials and building officials.

In such cases, research projects may be identified which could respond

to the technical need within the limited time constraints. Additional

types of technical support could include testifying before building

codes and standards generating groups, holding seminars on technical

issues resulting from implementation of the provisions and routine

distribution of research findings. The Applied Technology Council

and National Bureau of Standards are both expected to play a meaningful role.

Task 3 - Develop Guidelines for Evaluation and Inspection

Implementation of the new seismic design provisions by State and local

regulatory authorities will be aided considerably by model documents

relating to the following:

(a) Test data and information to be submitted to agencies by

producers

(b) Evaluation procedures, techniques, guides and reports to be

uti 1 ized

24
(c) Approval reports to be issued by agencies

(d) Inspection procedures, techniques, and certification systems

to assure compliance to the standards

(e) Data and information to be submitted to local enforcement

agencies pertaining to construction, installation and/or

occupancy.

The required manuals for use of building inspectors and evaluators will

be developed in consultation with the building industry, regulatory

agencies, and other segments of the building community. Every attempt

will be made to make the manual easy to use under field conditions

by regulatory officials at the inspector/evaluator level. Pilot field

testing of the manuals and resulting modifications will precede distribution and use on a national level. The development of such a system

will consider and be based in part on existing regulatory programs

and evaluation/approval systems. The approach to be used will be based

on earlier NBS-developed Coordinated Evaluation System (CES) type models.

The following organizations have traditionally provided services of this

type:

° National Bureau of Standards

° National Conference of States on Building Codes and Standards,

Inc.

° Association of Major City Building Officials

° International Conference of Building Officials

° Building Officials and Code Administrators International

° Southern Building Code Congress International

° Structural Engineers Association of California

Task 4 - Laboratory Accreditation Criteria

This activity has as its objective the provision of a supporting base of

accredited testing and evaluation agencies required for implementing the

new seismic design provisions. This is particularly important in the

areas of electrical, mechanical and plumbing systems. It includes the

employment of associated ASTM Standards to evaluate and accredit agencies

to perform the new evaluation tasks that will be required and laboratories

to perform physical testing and compliance assurance functions required

by regulatory authorities. This task will also define and assist in

the establishment of the intrastate and interstate laboratory accreditations that will enable reciprocal exchange of creditable certifications

and approvals of building components, equipment and designs.

Work will be coordinated with the National Voluntary Laboratory Accreditation Program of the Department of Commerce and the established ASTM

standards committees (E-32 and E-36). It may be necessary to expand

coverage of existing standards relating to laboratory accreditation.

Development of necessary standardized test methods will be included

in this task.

25
The organizations that will be involved in this activity are:

° American Society for Testing and Materials

° National Bureau of Standards.

The schedule for carrying out the tasks of Phase IV suggests that Task 1 should be inititated shortly after the completion of Phase I and be

continued beyond the duration of adoption by regulatory authorities.

Task 2 would not be initiated until the adoption of Phase III has begun.

Duration would be indefinite.

Tasks 3 and 4 could both begin in the second year concurrent with the

later stages of Phase II and continue for a period of two years.

26
NBS-114A (REV. 11-77)

U.S. DEPT. OF COMM. 1. PUBLICATION OR REPORT NO. 2. Gov’t Accession

BIBLIOGRAPHIC DATA No. SHEET NBSIR 78-1549

3. Recipient’s Accession No.

4. TITLE AND SUBTITLE

Plan for the Assessment and Implementation of Seismic

Design Provisions for Buildings

5. Publication Date October 1978

6. Performing Organization Code

author(S) Charles Culver, Robert E. Chapman, Patrick W. Cooke Rmrp R. FI 1 i nnwnnrl . ft ft Fa-H-al .bmoc P Uav^-ic

®. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND AbDR ESS ^

,

. Edger V. Leyendecker

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. Project/Task/Work Unit No. 741-3478

11. Contract /Grant No. NSF/EMV77-1 5034

12. Sponsoring Organization Name and Complete Address (Street, City, State, ZIP)

National Science Foundation

1800 G. Street

Washington, D.C. 20550

13. Type of Report & Period Covered

Final

14. Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

16. ABSTRACT (A 200-word or less factual summary of moat significant information. If document includes a significant

bibliography or literature survey, mention it here.)

This plan deals with the assessment and implementation of tentative seismic design provisions developed by the Applied Technology Council as part of the Cooperative Federal

Program in Building Practices for Disaster Mitigation of the National Science Foundation

and the National Bureau of Standards. The plan was prepared based on comments received

from a broad spectrum of representatives of the building community. The National Bureau

of Standards invited participation from a broad spectrum of interests to help develop the

plan. Trade associations, industry group, professional organizations, the model code

organizations, standards organizations and Federal agencies were included; groups with

national representation rather than regional or local interest were selected.

The plan includes four phases (1) Review and Refine Tentative Provisions, (2) Trial

Designs and Impact Assessment, (3) Consideration and Adoption of Provisions, and (4)

Assistance to Facilitate implementation. It can form the basis for the assessment and

implementation of the tentative seismic design provisions. As the effort proceeds, it

nay be necessary to refine the plan. Additional details will need to be specified for

the individual tasks. These will be influenced by the procedure adopted to carry out

the activities.

17. KEY WORDS (six to twelve entries; alphabetical order; capitalise only the first letter of the first key word unless a proper name; separated by semicolons)

Assessment; buildina codes; building design; disaster mitigation; earthquakes;

engineering; implementation; standards.

18. AVAILABILITY Unlimited 19. SECURITY CLASS

(THIS REPORT)

21. NO. OF PAGES.

I

1 For Official Distribution. Do Not Release to NTIS

UNCLASSIFIED

31

I ! Order From Sup. of Doc., U.S. Government Printing Office Washington. D.C. 20402. Stock No. SN003-003

20. SECURITY CLASS

(THIS PAGET

122. Price

Lj Ordfer From National Technical Information Service (NTIS) A A Springfield, Virginia 22151 UNCLASSIFIED

$4.50

USCOMM-DC 8«088-Fa 78