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{
"Added Entry": "Pielert, J. H.\nSchwab, Alvin R.\nYokel, Felix Y.\nUnited States. National Bureau of Standards.",
"Author": "Yokel, Felix Y.",
"Bibliography": "Includes bibliographical references.",
"CGP Record Link": "https://catalog.gpo.gov:443/F/?func=direct\u0026doc_number=001070206\u0026local_base=GPO01PUB",
"Content Type": "text",
"Description": "1 online resource.",
"Format": "online resource",
"General Note": "1975.\nContributed record: Metadata reviewed, not verified. Some fields updated by batch processes.\nTitle from PDF title page.",
"Internet Access": "https://purl.fdlp.gov/GPO/gpo98202",
"Item Number": "0247-D (online)",
"OCLC Number": "(OCoLC)929881805",
"Published": "Gaithersburg, MD : U.S. Dept. of Commerce, National Institute of Standards and Technology, 1975.",
"Series": "(NBSIR ; 75-715.)",
"SuDoc Number": "C 13.58:75-715",
"System Number": "001070206",
"Title": "The implementation of a provision against progressive collapse /",
"URL": "https://doi.org/10.6028/NBS.IR.75-715\nAddress at time of PURL creation https://www.govinfo.gov/content/pkg/GOVPUB-C13-4c182640e136145171eb015ff30d5303/pdf/GOVPUB-C13-4c182640e136145171eb015ff30d5303.pdf"
}
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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.
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text/markdown
# NBSIR 75-715
# The Implementation of a
# Provision
# Against
# Progressive Collapse
FelixY. Yokel,
### JamesH. PielertandAlvin R.
### Schwab
CenterforBuildingTechnology Institute forAppliedTechnology National Bureau ofStandards Washington, D.C.
### 20234
August 1975
### Prepared for Office ofPolicy
### Developmentand
### Research
### Department of
### Housingand
### Urban
### Development Washington,
### D.C.
### 20410IMBSIR
### 75-715
## THEIMPLEMENTATIONOFA
## PROVISION
## AGAINST
## PROGRESSIVE
## COLLAPSE
Felix Y. Yokel,
### James H. PielertandAlvin R.
### Schwab
Center forBuildingTechnology Institute forAppliedTechnology National Bureau ofStandards Washington,
## D.C 20234
August 1975
Prepared for OfficeofPolicy
### Developmentand Research Department of
### HousingandUrban
### Development Washington, D. C. 20410
U.S.
## DEPARTMENTOF
## COMMERCE, RogersC.B.
### Morton, Secretary
### JamesA. Baker, III,
### UnderSecretary Dr. BetsyAncker-Johnson, AssistantSecretaryforScience
### andTechnology
### NATIONALBUREAUOF
### STANDARDS, ErnestAmbler, ActingDirectordfewn,:? .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
### APROVISION
### AGAINST PROGRESSIVE COLLAPSE
### by •
### ' «KSj3feY
### FelixY.
### 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.
### KeyWords :
### Building systems;
### housing systems;
### large-panel structures;
### precast concrete construction;
### progressive collapse;
### structural design
### structural joints.
ii1.
### Introduction In 1969 the
### Department of
### Housing and
### Urban
### Development (HUD)
### initiated
### Operation Breakthrough, a
### programdesigned 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]-'-
### whichwere 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 6touted 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
### manneAMitiUn one 6ton.y
### level to
### one face of
### the element and of
### alt i>pace dividenA -iupponted by
### the
### element on.
### attacked to it. oJz^t: KnalyiiM and/on. phyi>icjal
### simulation oCommentany:
### 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 andwas
### tentativelyadopted
### 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
### interiorwalls, or
### between a corneA and
### either an
### inteAlor
### wall or a
### primary
### structural membeA. This
### criterionwas
### written
### with gas
### explosions inmind, 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
### criterionprovides 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
### criterionwas
### proposed, the
### matter of
### progressive collapse has
### been under
### considerationby
### 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
### systemwas
### 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
### bearingwalls (1)
### typically 28 ft x 8 ft-7 1/2 in X 8 in (8.53
### m x 2.63
### mx 20.3 cm);
### precast
### prestressed floor
### planks (2),
### typically 32 ft X 8 ft X 6 in (9.75
### mx 2.44
### m x 15.2 cm) and 22 ft-4 in x 8 ft x 4 in (6.81
### m x 2.44
### mX 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
### mx 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 ft-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
### bearingwalls 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
### bearingwalls 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.
### Aproblem,
### 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
### withinwhich 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
### mx 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
### mX 3.05
### mx 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
### windowpanels (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 trans
### mitting tensile and shear forces. As in the case of the
### Dillon System, all
### bearingwalls are
### designed as "strong" walls. Again, loss of the
### floor and
### ceiling in an
### interior unit
### would not cause
### collapse of the
### bearing
### walls
### whichwould 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
### EuropeanWates 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
### mX 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
### bearingwalls 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
### unreinforced .
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
### bearingwalls (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 sup
### port for the
### strong
### exterior walls. The
### interior
### walls and floors are not
### designed to
### resist 5
### psi (34.5 kPa)
. If any
### interior
### bearingwall 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
### cantilevermoment
### 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
### systemwas also
### designed to
### meet the
### following
### prescriptive provisions of
### AddendumNo. 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
### mx 15.2 cm); 6 in (15.2 cm)
### thick
### longitudinal corridor
### wall panels (3); 10 in (25.4 cm)
### thick
### facade (windowwall)
### 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
### bearingwalls range
### from 10 ft (3.05 m) to 12 ft (3.66 m) .
It canbe 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
### shouldnot 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
### ADHKby the
### reinforced joint (see
### figure 11).
### Wall panels
### ADHE and
### DCGH are
### connected to
### parapet panels
### LKDAand 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 canbe
### shown to exist
### whenbearing
### 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
### mx 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
### mx 3.71
### mX 15.2 cm). Clear
### floor spans
### between transverse
### bearingwalls 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
### generallyby
### alternate paths of load support, except for some
### isolated interior
### wall panels
### whichwere 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
### betweenbearingwalls range
### from 19 ft-5 in (5.92 m) to 31 ft-8 in (9.65 m) and the spaces
### between transverse
### bearingwalls 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"
### bearingwalls always
### include the end
### walls and the cross
### walls following the endwalls. The systems
### have the
### common
### problem of
### providing lateral support to the end walls. This
### problemwas 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 canbe
### identified for the
### long-span systems
### using strong
### bearingwalls,
### 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
### bearingwalls, and
### particularly, on
### anchorage of this
### reinforcement into the
### corridor slab.
5The
### 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 rein
### forcement 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
### bearingwalls, ties
### between transverse
### bearingwalls 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
### eventuallybe
### 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.
66.
### 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,
### AddendumNo. 1 (1970) to CP116,
### The
### Structural Use of
### Precast
### Concrete (London, U.K. , 1970) .
USCOMM-NBS-OC 71. Hollow-core bearingwalls
2. Precast Prestressed Floor Planks 3. Precast Stairwell and Balcony Panels 4. Heart Modules 5. Double "T" Exterior Panels
### Figure 1
### Typical
### Portion
## ofa
### Floor Flan
### for the
## FCE Dillon
### System#4OWLS. 2-0" X?-0"
### @24"
4 X4
-W2.9 XW2.9
### ^1
-DOWELS TYPICALEXTERIORWALL-TOFLOORJOINT
, , HOLLOWCORE J- iiM' T
# —
.
# — —
'
T \ \ 4X4
-W2.9 XW2.9 1 #4OWLSX4-0"
### @24"
#4 X4-0"
### @ 18" CAST-IN-PLACECONCRETE
I
### —; : _ ~ 4- Q
# —
TYPICALINTERIORWALL-TO-ROORJOINT POSITIONINGDOWEL LIFTINGHOOK
PORTION HORIZONTALSECTIONOFTYPICALHOLLOW COREWALLPANEL
### Figure 2
### Typical
### Hollow Cove Wall
### Panel
## and Floor to
### Wall
### Joint Details
## ofFCE -
### Dillon
### System
\
### CAST IN
### PLACE
### TOPPING
### PRECAST
### PRESTRESSED
### PLANK
### Figure S
### Typiaal Detail
## of Specially
## DesignedPartition -
## FCE Dillon
### System
## STRONG
PARTITION
## FLOOR
: t
## EXPLOSION f
### I
## REACTIONBY PARTITION
## REACTIONBY
### PARTITION
## END
## WALL
# FTTTTTTT
# MMM
# M
Figure 4
### Effect
## of Specially
## DesignedPartition
## 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
### System1, FLOORPANEL
2 EMBEDDED INSERT 3 CONNECTORPLATE 4 FRICTIONBOLTS I BEARINGWALLPANEL 2. FLOOR PANEL 3. WALL INSERT-TOP 4. WALL INSERT-BOTTOM 5. METAL SHIMS 6. FLOOR INSERT 7. CONNECTIONMAKE-UPPIECES 8. FRICTIONBOLTS CONNECTIONA FLOORTOFLOOR CONNECTION B
WALLTOFLOOR
### Figure 6
### Typical
### Panel
### Connections
### forDescon Concordia
### System
6 l/2'l5l/< 2'-8" 5'
### -4"
9" 9" ReinforcedBand 2'-8"
Prestressing Stand
### 4*7 Bot
### 6*7 Top
•<7 / '*
# 7^ ^*'4(S>24"0.i
### r ofReinforcedBand ft Floor Panel
### Figure 7
### Section Through.
### Strong Floor Panel
## ofDesoon
### Concordia
### System
]
### Figure 8
### Portion
## ofFloor Plan
## ofRouse-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
## ofRouse Wates
### System1. Transverse End Wall Panel 2. Transverse Interior Wall Panel 3. CorridorWall Panel A. Facade Panels
5. Floor Panels 6. BalconyUnits
# ©
-© Figure 10
### Portion
## ofTypical
### Floor Plan
## of Camci
### System
\I 1/2- 11/2"
5I/?
TYPICALVERTICALJOINT
=1/4" 4l/2'i
EXTWAU. PANEL
TYPICALINTERIORHORIZONTALJOINT TYPICALEXTERIORHORIZONTALJOINT
### Figure 11
### Typical
### ConnectionDetails
## 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 SystemNBS-n4A (REV. 7-73) U.S. DEPT. OFCOMM.
### BIBLIOGRAPHIC
### DATA SHEET 1.
### PUBLICATIONOR
### REPORTNO.
### NBSIR
### 75-715 2. Gov'tAccession
No. 3. Recipient'sAccessionNo.
4.
### TITLE
### ANDSUBTITLE
### The
### Implementation of
### a
### ProvisionAgainst
### Progressive Collapse 5. PublicationDate
6. Performing OrganizationCode
7.
### AUTHOR(S)
### Felix Y.
### Yokel,
### James H.
### Pielpri-
### anH
### Al^Hn R <^nh,.T=,h 8. Performing Organ. ReportNo.
### NBSIR 75-715 9.
### PERFORMINGORGANIZATION
### NAMEANDADDRESS
### NATIONAL
### BUREAUOF
### STANDARDS
### DEPARTMENTOF
### COMMERCE WASHINGTON, D.C. 20234 10. Project/Task/Work UnitNo. 11. Contract/GrantNo.
12. Sponsoring Organization
### Name andCompleteAddress (Street, City, State, ZIP)
### Department of
### Housing and
### UrbanDevelopment 451
### 7th
### Street, S.
### W.
### Washington, D. C.
### 20410 13. Type of Report 8c Period Covered
14. SponsoringAgencyCode 15.
### SUPPLEMENTARYNOTES
16.
### ABSTRACT (A 200-wordorless factualsunmaryolmostsi^iticant information. Ifdocument includes a significant bibliographyor literature survey, mention ithere.)
### 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; capitalizeonly the first letterof the firstkeywordunless aproper name; separatedbysemicolons)
### Building systems;
### housing systems;
### large-panel structures;
### precast concrete
### construction
### progressive collapse;
### structural design;
### structural joints. 18.
### AVAILABILITY [X] Unlimited
I !ForOfficial Distribution. DoNotRelease toNTIS
I IOrderFromSup. of
### Doc, U.S. Government PrintingOffice Washington, D.C. 20402, SD Cat. No.
## CU
IX! OrderFromNational Technical InformationService (NTIS) Springfield, Virginia 22151 19.
### SECURITY
### CLASS
(THIS
### REPORT)
### UNCLASSIFIED 20.
### SECURITY
### CLASS (THIS
### PAGE)
### UNCLASSIFIED 21.NO.
### OF
### PAGES
## 23 22. Price
## $3.25 USCOMM.DC 29042-P74ij " ,>•.• ,-.7 r.iA
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