NBSIR 75-715

The Implementation of a Provision

Against Progressive Collapse

Felix Y. Yokel, James H. Pielert and Alvin R. Schwab

Center for Building Technology

Institute for Applied Technology

National Bureau of Standards

Washington, D.C. 20234

August 1975

Prepared for Office of Policy Development and Research

Department of Housing and Urban Development

Washington, D.C. 20410

IMBSIR 75-715

THE IMPLEMENTATION OF A PROVISION

AGAINST PROGRESSIVE COLLAPSE

Felix Y. Yokel, James H. Pielert and Alvin R. Schwab

Center for Building Technology

Institute for Applied Technology

National Bureau of Standards

Washington, D.C 20234

August 1975

Prepared for Office of Policy Development and Research

Department of Housing and Urban Development

Washington, D. C. 20410

U.S. DEPARTMENT OF COMMERCE, Rogers C.B. Morton, Secretary

James A. Baker, III, Under Secretary

Dr. Betsy Ancker-Johnson, Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Acting Director
dfewn,:? .RfliviA bfis'li©

\
Table of Contents

Page

Abstract 11

1. Introduction 1

2. The Criterion and Its Interpretation 1

3. Case Histories 2

3 . 1 General 2

3.2 The FCE-Dillon System 2

3.3 The Descon Concordia System 3

3.4 The Rouse-Wates System 3

3.5 The Camel System. . 4

3.6 The BSI System 5

4. Some Common Characteristics of the Design Solutions 5

5. Conclusions 6

6. References ..... 7

i
THE IMPLEMENTATION OF A PROVISION AGAINST PROGRESSIVE COLLAPSE

by • ' «KSj3feY

Felix Y. Yokel, James H. Pielert

and Alvin R. Schwab

. . .

.

' J :.:h '-lrjc . iv: .i.' M- fk'ti

The design solutions used by five U.S. precast concrete housing

systems to comply with a provision against progressive collapse

are studied and compared. Some common characteristics of the

design solutions are identified.

Key Words : Building systems; housing systems; large-panel structures;

precast concrete construction; progressive collapse; structural design

structural joints.

ii
1. Introduction

In 1969 the Department of Housing and Urban Development (HUD) initiated Operation

Breakthrough, a program designed to encourage the development and introduction of industrialization into the housing industry in the United States. Under the Breakthrough program a number of housing systems were selected, evaluated, and constructed on demonstration sites.

The National Bureau of Standards, on behalf of HUD, drafted criteria [1]-'- which were used

to guide the development and subsequent evaluation of these housing systems. These "Guide

Criteria" contained a provision against progressive collapse under catastrophic loading which

was not previously contained in any U.S. code or standard (Progressive collapse may be defined as a chain reaction of failures following damage to only a relatively small portion of a structure) . This report discusses the implementation of this provision.

2. The Criterion and its Interpretation

The criterion against progressive collapse used in Operation Breakthrough is quoted below:

o Re.quAJime.nt

Ex.plo&'ioYid OK. othnn. c/xtoM trophic toadi, on anij onz. i,tofiLj Zzvzl i>houJid not caoie

pfLogK-U-itve. iitAiLcJiiJuxJi cotla.p6t at otkeA ^eueXi.

o CfUteAion:

The. cAitetiion apptie.6 to baitding^ ifouA 6 touted on. higheA.. At a load level o{, one dead +0.5 live, the aaddental fiesnoval of, any one o{, the iotlowtng [load] ^apponXing

6tAacXuAal elejmenti at one level, should not cauie colZapie of the 6tM.ucXuAe on anotheJi

level:

a. tiMo adjacent Mall paneZi fomlng an exteAlofi con.neA

b. one MolZ panel tn a location otheA than an exX.eAA.on. conneA

c. one column on. otheA element of the pnlmany itnuctuAol iuppont -i>y6tem.

ThJj, cAAjteAlon Li waived if the above-mentioned ^tnactuAal element on elements one

capable of n.Z6ij,ting a pn.ti>i>an.e of 5 p6i (34.5 kPa) , applied in the mo6t cnJjticat

manneA MitiUn one 6ton.y level to one face of the element and of alt i>pace dividenA

-iupponted by the element on. attacked to it.

o Jz^t:

KnalyiiM and/on. phyi>icjal simulation

o Commentany:

The need fon thit, nequinement i6 emphasized by several n.ecent caXastAopheM . The

collapse of the Ronan Point Kpantment BuJlding, London, demonstnated one sounce of

catastnophic loading, namely a gas explosion. The Tni.bu.nal investigating the cause of

tka, collapse [2] pointed out tkaX. "the problem of pn.ogne.ssive collapse had not been

consideAed by most stnactuAal engineers conceAned with the development of tall systembailX. blocks" . Systems meeting thts n.equAAement would be designed to withstand local

explosion. This cnAXenlon is conseAvative and was tentatively adopted in accordance

with the tnibunal's recommendations.

The won.d "panel" is used to describe a portion of an interior or exterior bearing

wall between tu)o primoAy structural membeAs, or between two interior walls, or between

a corneA and either an inteAlor wall or a primary structural membeA.

This criterion was written with gas explosions in mind, but it was also envisioned that

other abnormal loads (loads not normally considered by designers) may occur and cause the

failure of a primary structural member. The progression of collapse considered in this criterion is in a vertical direction. There are no explicit limitations on the horizontal spread of

^Figures in brackets indicate literature references.

1
progressive collapse within a single story. The load considered is 50 percent of the design

live load, accounting for the low probability of the coincidence of a catastrophic load with full

design live load. The criterion does not require consideration of the debris loading that the

collapse of part of the structure could generate. The criterion provides the option of either

designing "strong" members, capable of resisting the 5 psi (34.5 kPa) pressure, or providing an "alternate path" of load support.

In the implementation of the criterion the assumption was made that a wall panel can only be considered "strong" if the panel itself, as well as the lateral supports necessary

to insure its stability under the stipulated minimum load of dead plus 0.5 live, would survive

after the 5 psi (34,5 kPa) pressure is applied.

It is not the intent of this report to discuss the need for, or the adequacy of, the

quoted criterion. ' Since the time the criterion was proposed, the matter of progressive

collapse has been under consideration by professional committees in the U.S., however, no formal recommendations have been adopted by the profession.

3. Case Histories

3 . 1 General

Selected case histories of Operation Breakthrough systems are described in order to illustrate

specific approaches which were judged by designers to satisfy the stated criterion. It is

realized that the design solutions described do not necessarily represent the only way in

which the criteria could have been satisfied. However the case histories illustrate some

of the approaches that other designers might consider when faced with the task of increasing

the resistance of buildings to progressive collapse.

The general features of these systems were previously described elsewhere [3], although

specific features relating to progressive collapse have not been discussed to the extent

presented below.

3.2 The FCE-Dillon System .

This system was developed in the U.S. and adapted to meet the Breakthrough requirements.

A typical portion of a floor plan is shown in figure 1. The structural components, as numbered in figure 1, are: precast, hollow-core bearing walls (1) typically 28 ft x 8 ft-7

1/2 in X 8 in (8.53 m x 2.63 m x 20.3 cm); precast prestressed floor planks (2), typically

32 ft X 8 ft X 6 in (9.75 m x 2.44 m x 15.2 cm) and 22 ft-4 in x 8 ft x 4 in (6.81 m x 2.44 m X 10.1 cm); 8 in (20.3 cm) thick balcony and stairwell floor panels (3), preassembled

kitchen and utility (heart) modules (4) resting on 8 in (20.3 cm) thick floor panels of

typical floor-plank dimensions, "double T" exterior walls at the end of the stairwells (5), 43 ft-7 in high X 7 ft-7 in wide (13.28 m x 2.31 m) ; and elevator-shaft units not shown in'the portion of the floor plan in figure 1. Clear spans between bearing walls are 22 ft (6.71 m) and

31 f t-8 in (9.65 m)

.

A typical hollow-core bearing wall section and floor to wall joint detail are shown in figure 2. After erection and appropriate shoring, vertical reinforcement is inserted in some

of the hollow cores, and horizontal reinforcement is placed on top of the floor planks. Subsequently, the reinforced wall cores are filled with concrete and a cast in place concrete

topping is placed on the floor planks to a total floor thickness of 8 in (20.3 cm). The

horizontal and vertical reinforcement is continuous through interior joints, and horizontal

bars are anchored in the exterior wall joints to develop their full tensile strength. There

are reinforcement ties between the floor slabs of the heart modules and adjacent slabs.

All bearing walls are designed as "strong" members and thus are capable of resisting

the stipulated 5 psi (34.5 kPa) pressure. This approach is not difficult to implement since the unsupported (floor to ceiling) height is only 8 ft (2.44 m) . However, tha floor planels have a much larger unsupported span and can not be economically designed to resist an upward or downward pressure of 5 psi (34.5 kPa) . In the case of a space enclosed by two interior
bearing walls even floor panels on two consecutive levels between these walls could fail without

depriving the walls of their lateral support, which in this case would be provided by

floor panels on the other side of the walls. A problem, however, arises when one or both

of the bearing walls are exterior walls, since the loss of a floor panel would

deprive these walls of lateral support, causing a stability failure. This problem is

solved by providing specially-strengthened partitions. A typical detail of such a partition is shown in figure 3. The effect of the partition is illustrated in figure 4. While

the partition in the space within which the 5 psi (34.5 kPa) pressure is applied is not ex- pected to survive, the partitions in the stories above and below this space provide reaction

forces, thus reducing the effective span of the floor and ceiling panels. The reaction force

transfered to the partition is resisted by one or two successive floor (ceiling) panels or transfered directly to the foundation. If the 5 psi (34.5 kPa) pressure is applied in the space

below the roof, the roof panel would fail. However, a roof panel failure would not trigger a progressive collapse. Since the specially-designed partitions are located where partitions

are required in any case, the cost increase does not exceed the difference in cost between

the special partitions and the non-loadbearing drywall partitions used in other parts of the

housing unit.

3.3 The Descon Concordia System

The Descon Concordia System is a large-panel concrete system that was developed in

Canada. The structural components of the system are shown in figure 5, and consist of:

precast concrete wall panels (1), typically 30 ft x 8 ft x 6 1/2 in (9.14 m x 2.44 m x 16.5 cm)

with 1 1/2 in (3.8 cm) insulation and a 3 in (7.6 cm) thick concrete cladding panel added

for exterior walls; precast prestressed floor panels (2), typically 22 ft x 10 ft x 6 1/2 in

(6.71 m X 3.05 m x 16.5 cm); two panelized longitudinal shear walls not shown in figure 5,

located on opposite sides of the corridor, 18 ft-1 in (5.51 m) long and 10 in (25.4 cm) thick;

and non-loadbearing window panels (3) . Clear floor spans between transverse bearing walls

are 21 ft-5 in (6.53 m)

.

All panels are connected by bolted connections which are located as shown in figure 5 (A & B)

Typical bolted connections are shown in figure 6. All connections are capable of transmitting tensile and shear forces.

As in the case of the Dillon System, all bearing walls are designed as "strong" walls.

Again, loss of the floor and ceiling in an interior unit would not cause collapse of the

bearing walls which would receive lateral support from floor panels on the other side. However, an exterior bearing wall could collapse after losing the lateral support from a floor.

Thus special "strong" floor panels were provided. The location of these panels is shown in

figure 5. Instead of strengthening an entire panel, each of the strong panels was provided with

two heavily-reinforced bands, as shown in figure 7. These bands were designed to survive the

5 psi (34.5 kPa) pressure while the rest of the panels would break away at a lower pressure.

After an explosion these strong bands together with other remaining panels, such as balcony and

corridor floor panels, would provide lateral support to the exterior wall.

3.4 The Rouse-Wates System

This system is an adaptation of the European Wates system. Figure 8 is a portion of

a typical floor plan. The structural elements are: "strong" bearing wall panels (1); interior bearing wall panels (2) ; nonbearing exterior wall panels (3) ; corridor wall panels (4)

;

regular floor panels (5); "strong" floor panels (6); and corridor floor panels (7). Typical

panel sizes for the floor plan in figure 8 are 19 ft-9 in x 7 ft-5 in x 8 in (6.02 m x 2.26 m X 20.3 cm) for floor panels, and 22 ft x 8 ft x 7 in (6.71 m x 2.44 m x 17.8 cm) for

bearing wall panels. Clear floor spans between transverse bearing walls are 19 ft-5 in

(5.92 m)

.

Figure 9 shows a typical cast in place horizontal joint at an interior bearing wall

panel. The joint provides reinforcement ties between adjacent floor elements and between

floor elements and their supporting bearing walls. There are no vertical ties between

successive bearing-wall panels. Vertical joints are unreinf orced

.

3
Compliance with the criterion, as documented by the designers, is by a combination of

"strong" bearing walls and alternate paths of load support. As shown in figure 8, two parallel strong bearing walls (1) enclose the spaces next to the exterior walls. As in the

previously-discussed cases, strong floor panels (6) must also be provided to insure lateral support for the strong exterior walls. The interior walls and floors are not designed to resist

5 psi (34.5 kPa) . If any interior bearing wall is removed, the floor supported by this wall will

fail, and the wall above the floor is designed to act as a cantilever girder connected to the

corridor wall. The longitudinal reinforcement in the joint in figure 9 is anchored so that

tensile forces at the top of the suspended wall can be transmitted to the corridor slab.

According to the designers, the cantilever moment would be resisted by the corridor slabs

at the top and bottom of the suspended wall. The vertical joint between the suspended wall

and the corridor wall would resist the cantilever shear.

The Rouse-Wates system was also designed to meet the following prescriptive provisions

of Addendum No. 1 (1970) to the British Standard Code of Practice CP116 [3]:

1. horizontal wall to floor joints capable of resisting 1700 lb per ft (2.48 kN/m)

at the bottom of the wall,

2. an uninterrupted peripheral tie at each floor level to resist a force of 9000 lb

(40.03 kN)

,

3. internal ties, anchored to the peripheral tie, capable of resisting a force of 1700

lb per foot (2.48 kN/m) in the longitudinal direction and 850 lb per foot (1.24

kN/m) acting over half a bay width in the transverse direction (the bars in the

transverse direction were concentrated in the horizontal joints between transverse

bearing walls)

.

3.5 The Camci System

This system is an adaptation of the European Tracoba System. Figure 10 shows a portion of a typical floor plan. Typical connection detail is shown in figure 11. The main

structural components are: transverse exterior wall panels (1), 11 in (27.9 cm) thick, including an insulating layer between a 6-in (15.2 cm) thick interior concrete panel and a 3 in

(7.6 cm) thick exterior concrete panel; transverse interior wall panels (2), typically 24 ft-10 in X 8 ft X 6 in (7.57 m x 2.44 m x 15.2 cm); 6 in (15.2 cm) thick longitudinal corridor wall panels (3); 10 in (25.4 cm) thick facade (window wall) panels (4); floor panels

(5), typically 25 ft-1 in x 12 ft-1 in x 5 1/2 in (7.65 m x 3.68 m x 14.0 cm); roof parapets,

not shown in figure 10, 10 in (25.4 cm) or 11 in (27.9 cm) thick and extending 7 ft-3 in

(2.21 m) above the roof level; and externally-attached balcony units (6). Clear floor spans

between transverse bearing walls range from 10 ft (3.05 m) to 12 ft (3.66 m)

.

It can be seen from figure 11 that continuous reinforcement (anchored hairpin reinforcement) extends through all the horizontal and vertical cast-in-place joints. There

are also mechanical connectors providing vertical continuity between all the transverse

walls, and between all roof parapets and their supporting walls.

Compliance with the progressive collapse criterion is entirely by alternate paths of

load support. Thus removal of any one bearing wall panel or any two adjacent wall panels

at an exterior corner should not cause progressive collapse. The most critical case is

illustrated by figure 12 and occurs in the story below the top story. One gable wall and

one facade wall are removed. It is assumed that floor EFGH is left in place and has to support 1/2 the live load. The slab is supported by bearing walls along sides EF and GF. Side EH is suspended from panel ADHK by the reinforced joint (see figure 11). Wall panels

ADHE and DCGH are connected to parapet panels LKDA and KJID by vertical connectors and by- continuous vertical reinforcement in joint HDK, which also connects the two wall panels to each other. The suspended wall panels are also connected to adjacent panels through vertical joints GC and EA. Panel ADHE, as well as panel DCGH together with parapet KJID, act as
cantilever girders. Shear is resisted by the vertical joints and by parapet panel KJID, and

the floor and roof slabs at joints EF, AB, GF and CB assist in resisting the moments by

providing moment-resisting couples. Similar less critical alternate paths of load support

can be shown to exist when bearing wall panels at lower levels are removed.

3.6 The BSI System

This system is an adaptation of the European Balency-Schuhl system. A portion of a typical floor plan is shown in figure 13. Figure 14 shows typical joint detail.

The main structural components are: exterior wall panels (1), 7 1/2 in (19.1 cm)

thick; interior wall panels (2) including corridor walls, with a maximum size of 21 ft x 8 ft X 6 in (6.40 m X 2.44 m x 15.2 cm); "strong" interior wall panels (3), 6 in (15.2 cm)

thick; and floor panels (4) with a maximum size of 21 ft-6 in x 12 ft-2 in x 6 in (6.55 m x 3.71 m X 15.2 cm). Clear floor spans between transverse bearing walls range from 11 ft

(3.35 m) to 12 ft (3.66 m)

.

The vertical joints shown in figure 14 provide continuous (interlocking) reinforcement in

the horizontal, as well as the vertical direction. Horizontal joints provide ties between

adjacent floor elements and between floor elements and the top of supporting bearing walls.

Vertical ties between successive bearing walls are only provided in the end walls.

Compliance with the progressive collapse criterion is generally by alternate paths of

load support, except for some isolated interior wall panels which were designed as strong

panels. The alternate paths are made possible by the continuity of the vertical joints.

For example, if panel FllO in figure 13 is removed, the panel above will be supported by

panels F113 and FlOO, a panel enclosing an exterior balcony. The continuous vertical joints

would also permit cantilever support of larger portions of the building in a manner similar

to that discussed for the Camci system. On the other hand, panel RlOl which does not have

this type of support from vertical joints, was designed as a "strong" panel.

4. Some Common Characteristics of the Design Solutions

The systems described in Section 3 can be categorized as long-span systems and shortspan systems. The long-span systems include FCE-Dillon, Descon Concordia and Rouse-Wates.

Their clear floor spans between bearing walls range from 19 ft-5 in (5.92 m) to 31 ft-8 in

(9.65 m) and the spaces between transverse bearing walls are sub-divided by non-loadbearing

partitions. The short-span systems are Camci and BSI, with floor spans ranging from 10

ft (3.05 m) to 12 ft (3.66 m)

.

All long-span systems relied on "strong" bearing walls to comply with the progressive

collapse criterion. The "strong" bearing walls always include the end walls and the cross walls following the end walls. The systems have the common problem of providing lateral

support to the end walls. This problem was solved by the three systems in three different

ways: FCE Dillon used specially designed partitions to provide intermediate support to the

floors; Descon-Concordia used floor panels with strong bands; and Rouse-Wates used strong

floor panels

.

No specific common joint-reinforcement requirements can be identified for the long-span

systems using strong bearing walls, except those arising from the requirement that connections between strong members must resist the reaction forces caused by the specified design

pressure of 5 psi (34.5 kPa) . In the case of the Rouse-Wates system, where an alternate path of

load support was intended for interior cross-wall panels, the designers used continuous horizontal reinforcement between the floor slabs resting on the transverse bearing walls and the

corridor floor slab, between the floor slabs resting on both sides of a transverse bearing

wall, and between the transverse bearing walls and the floor slabs above. The designers also

relied on longitudinal reinforcement on top of transverse bearing walls, and particularly,

on anchorage of this reinforcement into the corridor slab.

5
The short-span systems relied primarily on alternate paths of load support. The

Camci system relied on a roof parapet to support the uppermost story. The following

joint reinforcement was needed in both systems to comply with the progressive collapse

criterion: (1) the vertical joints between adjacent and intersecting wall

panels were the most critical. These had to be reinforced horizontally to transmit horizontal tensile forces between adjacent wall panels, and vertically to resist tensile forces

between successive stories; (2) the horizontal joints between the corridor floor slabs and

slabs on the other side of the corridor walls were also critical. Reinforcement ties between the corridor floor slabs and the adjacent floor slabs and between the corridor and

transverse walls and the corridor floor slabs insured that the corridor slabs could be

engaged in resisting moments transmitted by cantilevering transverse bearing walls; (3) the

horizontal joints between transverse bearing walls and floor panels resting on both sides of

these walls were somewhat less critical, but in all cases reinforcement similar to that in

the horizontal joints at the corridor floor slabs was needed; (4) vertical reinforcement

ties between successive bearing walls panels, in addition to those provided by the continuous vertical reinforcement bars within the vertical joints, were only necessary in the

upper story of the Camci system where the roof parapet was engaged to support the uppermost

story. However it can be shown that such reinforcement would substantially increase the

load resistance of suspended bearing walls in stories below the top story.

5. Conclusions

The following conclusions are drawn from the study of the design solutions discussed in

this report

.

1. The systems with clear spans between transverse bearing walls greater than 19 ft (5.79 m)

had to use "strong" transverse bearing walls at least for the end walls and the

transverse walls next to the end walls. In all cases, special provisions had to be made to provide lateral support to the end walls.

2. The systems with clear spans of 12 ft (3.66 m) or less relied principally on an alternate paths of load support.

3. In short-span systems using an alternate path of load support the following joint reinforcement ties were the most critical: horizontal ties in the vertical joints between

adjacent or intersecting bearing walls; continuous vertical ties throughout the building in

the same joints; transverse horizontal ties between corridor floor panels and adjoining

floor panels; and ties between transverse walls and corridor walls and between transverse

walls and corridor floor panels. The alternate mode of load support was also assisted

by longitudinal horizontal ties between adjoining floor panels on either side of

transverse bearing walls, ties between transverse bearing walls and connecting floor

panels, and vertical ties between successive transverse bearing wall panels.

The preceeding conclusions are subject to the following qualifications:

1. The criterion states certain design conditions but does not cover the entire

spectrum of possible causes of progressive collapse. For instance; a gas explosion may remove more than the specified number of panels; debris load may cause progressive collapse; or collapse may propagate in the horizontal direction.

There is, as yet, no professional consensus as to which cases should be included

in, or excluded from, consideration.

2.. Provisions fair continuity of joints and miscellaneous ties, similar to those

listed in Section 3.4, may eventually be Imposed in addition to the rational

design conditions required by the criterion. Such prescriptive code provisions

could change the characteristics of design solutions.

3. The sample of five systems considered in this report is not very large, and the

design solutions do not necessarily represent the only way in which these systems

could have complied with the criterion.

6
6. References

[1] The Building Research Division Team, Guide Criteria for the Evaluation of Operation

Breakthrough Housing Systems, Accession Numbers PB-212055, 212056, 212058, National

Technical Information Service (Springfield, Va. , December 1970).

[2] Ministry of Housing and Local Government, Report of the Inquiry into the Collapse of

Flats at Ronan Point, Canning Town, Her Majesty's Stationary Office (London, U.K., 1968),

[3] Department of Housing and Urban Development^ Design and Development of Housing Systems

for Operation Breakthrough, U.S. Government Printing Office, (Washington, D.C., 1973).

[4] British Standards Institution, "British Standard Code of Practice for Large Panel

Structures, Addendum No. 1 (1970) to CP116, The Structural Use of Precast Concrete

(London, U.K. , 1970)

.

USCOMM-NBS-OC

7

1. Hollow-core bearing walls

2. Precast Prestressed Floor Planks

3. Precast Stairwell and Balcony Panels

4. Heart Modules

5. Double "T" Exterior Panels

Figure 1 Typical Portion of a Floor Flan for the FCE

Dillon System
#4 OWLS. 2-0" X ?-0" @ 24"

4 X 4 - W2.9 X W2.9 ^1

- DOWELS

TYPICAL EXTERIOR WALL -TO FLOOR JOINT

, , HOLLOW CORE

J- iiM' T—.—

'

T

\

\

4 X 4 - W2.9 X W2.9

1

# 4 OWLS X 4 -0" @ 24"

# 4 X 4-0" @ 18"

CAST-IN-PLACE CONCRETE

I—; : _ ~ 4- Q —

TYPICAL INTERIOR WALL-TO-ROOR JOINT

POSITIONING DOWEL

LIFTING HOOK

PORTION HORIZONTAL SECTION OF TYPICAL HOLLOW

CORE WALL PANEL

Figure 2 Typical Hollow Cove Wall Panel and

Floor to Wall Joint Details of FCE - Dillon System

\
CAST IN PLACE

TOPPING

PRECAST

PRESTRESSED

PLANK

Figure S Typiaal Detail of Specially Designed Partition - FCE Dillon System
STRONG

PARTITION

FLOOR

: t EXPLOSION

f

I

REACTION BY

PARTITION

REACTION BY

PARTITION

END

WALL

FTTTTTTT

M M M M

Figure 4 Effect of Specially Designed Partition

FCE Dillon System

\
1. Precast Concrete Wall Panels

2. Precast Concrete Floor Panels

3. Window Panels

A. Bolted Floor-Diaphragm Connections

Figuve 5 Structural Components of the Desoon Conaordia System
1, FLOOR PANEL

2 EMBEDDED INSERT

3 CONNECTOR PLATE

4 FRICTION BOLTS

I BEARING WALL PANEL

2. FLOOR PANEL

3. WALL INSERT-TOP

4. WALL INSERT-BOTTOM

5. METAL SHIMS

6. FLOOR INSERT

7. CONNECTION MAKE-UP PIECES

8. FRICTION BOLTS

CONNECTION A

FLOOR TO FLOOR CONNECTION B WALL TO FLOOR

Figure 6 Typical Panel Connections for Descon Concordia System

6 l/2'l5l/<

2' -8"

5' -4"

9" 9"

Reinforced Band

2'- 8"

Prestressing Stand 4*7 Bot

6*7 Top

• < 7 /

' * 7^

^*'4(S>24"0.i

r of Reinforced Band

ft Floor Panel

Figure 7 Section Through. Strong Floor Panel of Desoon

Concordia System

]
Figure 8 Portion of Floor Plan of Rouse-Wates System

1. Floor Panel

2. Cast in Place Concrete Joint

3. Transverse Joint Reinforcement

4. Longitudinal Joint Reinforcement

5. Lifting/Leveling Bolt

6. Leveling Cone

7. Precast Concrete Wall

8. Grout Bed

Figure 9 Typical Cast-in-Place Horizontal

Joint of Rouse Wates System
1. Transverse End Wall Panel

2. Transverse Interior Wall Panel

3. Corridor Wall Panel

A. Facade Panels

5. Floor Panels

6. Balcony Units

©

-©

Figure 10 Portion of Typical Floor Plan of Camci System

\
I 1/2- 1 1/2"

5

I/?

TYPICAL VERTICAL JOINT

= 1/4"

4l/2'i

EXT WAU. PANEL

TYPICAL INTERIOR HORIZONTAL JOINT TYPICAL EXTERIOR HORIZONTAL JOINT

Figure 11 Typical Connection Details of Camci System
Figure 12 Camoi System - Critical Condition for Progressive Collapse
Figure 13 Portion of a Typical Floor Plan of the BSI System
Figure 14 Typical Joint Details for BSI System
NBS-n4A (REV. 7-73)

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBSIR 75-7152. Gov't Accession

No.

3. Recipient's Accession No.

4. TITLE AND SUBTITLE

The Implementation of a Provision Against Progressive Collapse

5. Publication Date

6. Performing Organization Code

7. AUTHOR(S)

Felix Y. Yokel, James H. Pielpri- anH Al^Hn R <^nh,.T=,h

8. Performing Organ. Report No. NBSIR 75-715

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. Project/Task/Work Unit No.

11. Contract/Grant No.

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

Department of Housing and Urban Development

451 7th Street, S. W.

Washington, D. C. 20410

13. Type of Report 8c Period Covered

14. Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

16. ABSTRACT (A 200-word or less factual sunmary ol most si^iticant information. If document includes a significant

bibliography or literature survey, mention it here.)

The design solutions used by five U.S. precast concrete housing systems to comply

with a provision against progressive collapse are studied and compared. Some common characteristics of the design solutions are identified.

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

Building systems; housing systems; large-panel structures; precast concrete construction

progressive collapse; structural design; structural joints.

18. AVAILABILITY [X] Unlimited

I ! For Official Distribution. Do Not Release to NTIS

I I Order From Sup. of Doc, U.S. Government Printing Office Washington, D.C. 20402, SD Cat. No. CU

I X! Order From National Technical Information Service (NTIS)

Springfield, Virginia 22151

19. SECURITY CLASS

(THIS REPORT)

UNCL ASSIFIED

20. SECURITY CLASS

(THIS PAGE)

UNCLASSIFIED

21. NO. OF PAGES

23

22. Price

$3.25

USCOMM.DC 29042-P74
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