京都
᦬大 学 防 災 研 究 所 年 報 第 49 号 C 平 成 18 年 4 月
Annuals of Disas. Prev. Res. Inst., Kyoto Univ., No. 49 C, 2006

Seismic Performance Evaluation of Nonstructural Components:
Drywall Partitions

Tae-Hyung LEE, Mikiko KATO , Tomohiro MATSUMIYA, Keiichiro SUITA,
and Masayoshi NAKASHIMA


Nikken Sekkei Ltd., Japan

Synopsis
In spite of its significance in the context of performance-based earthquake engineering,
quantitative information on the seismic performance of nonstructural components is very limited.
From among the nonstructural components that are significant in the economic losses in buildings,
interior drywall partitions are selected for an experimental program. Four full-scale drywall
partitions with light-gage steel stud framing were tested to observe damage to cyclic loading
conditions. Effects of a door and an intersecting wall on the behavior of drywall partition arestudied. Damage was concentrated to perimeter regions where gypsum boards made contacts withceiling, floor, or columns. Dynamic loading did not amplify the damage to a drywall partition overthe damage observed from the quasi-static test. Damage-repair cost relationships show that the
repair cost reaches almost the initial cost under 2% radian interstory drift.
Keywords: nonstructural component, Performance-based earthquake engineering, drywall partition
1.

Introduction

After many years of efforts by researchers andpractitioners to develop performance-based earthquake
engineering (PBEE) methodologies, it is now obviousthat the issue of nonstructural components is one of themost critical elements of the PBEE methodology. Unlike
structural components, most of the nonstructuralcomponents, including architectural, mechanical,
electrical, and plumbing components, are vulnerable to a
relatively low level of earthquake. According toreconnaissance reports for recent earthquakes, namely
1989 Loma Prieta, 1994 Northridge, and 2001 Nisqually
earthquakes (Shephard et al. 1990; Hall 1995; Filiatrault
et al. 2001), economic loss due to nonstructuralcomponents generally exceeds that due to structuralcomponents. Taghavi and Miranda (2003) studied thecost distribution of three types of buildings, namely

offices, hotels, and hospitals, in terms of structuralcomponents, nonstructural components, and building
contents. The cost of nonstructural components is thehighest for all three types of buildings where its portion
ranges from 48% and 70% of the total cost. According to
Hirakawa and Kanda (1997), it is 40% for 210 reinforced
concrete (RC) buildings damaged from the 1995
Hyogo-ken Nanbu earthquake, while that for structuralcomponents is also 40%. Consequently, it is widelyagreed that the mitigation of nonstructural damage will
dramatically improve the protection of structures from
economic losses.
Among various nonstructural components, theinterior architectural component is one of the mostsignificant contributing components. Taghavi andMiranda (2003) reported that interior constructions andmechanical systems are the major source of cost
(20-30% for different types of buildings) while electrical㧙㧙systems and exterior closure cost almost 10% of the total
based on their investigation for various building types,
namely a mid-rise apartment, a hospital and officebuilding, and a high-rise hotel. The other nonstructuralcomponents such as elevators, escalators, and roofing do
not contribute more than 5% to the total nonstructuralcomponent cost.
Another important issue related to nonstructuralcomponents in earthquake engineering is that
nonstructural component failure may be a significant
threat to life safety. In addition to an indirect threat to life
safety from closing hospitals, Rihal et al. (1998) pointed
out a potential disaster of the theatre-like structure where
several hundred square feet of plaster ceiling may fall on
seating areas below during a large earthquake event.
Despite the significant amount of research alreadyconducted within the framework of the PBEE
methodology, there is limited information in theliterature on the relationship between structural responses
and nonstructural damage and consequences of thedamage. Moreover, most of the existing information
about the performance of nonstructural components isfrom previous earthquakes. Villaverde (1997)
summarized previous experimental studies and fieldobservations of various secondary structural elements,
including mechanical and architectural components andbuilding contents, and pointed out the scarcity ofavailable experimental data.
Among various nonstructural components ofbuildings, this study focuses on the interior drywall
partition with steel-stud framing used in typical Japanesebuildings. A number of studies have been conducted on
this type of component (Freeman 1977; Rihal 1982;
Adhams et al. 1990; Serrett and Ogunfunmi 1996; Liew
et al. 2002; McMullin and Merrick 2005). Most of themfocused on evaluating the load-deformation relationshipof drywall partitions in terms of the load-carrying
capacity under quasi-static load, either monotonic or
cyclic. Rihal (1982) and McMullin and Merrick (2005)
investigated the damageability of drywall partitions using
various damage thresholds. However, none of theseprevious studies considered the drywall partition
specimens that were mounted on the primary structures
such as floors, ceilings, and columns. They did notevaluate the repair costs corresponding with detailed
damage thresholds, which is critical in PBEE.
The purpose of this study is to characterize theseismic performance of the drywall partitions typicallyused in Japanese building constructions. For a realistic
representation, a full-scale drywall partition is mounted
on a primary structural system. The relationship between
the damage to a drywall partition and the structural
responses such as the interstory drift are developed underquasi-static cyclic loading conditions. The repair costcorresponding to a specific interstory drift is estimated.
The effects of the existence of a door, an intersecting
wall, and a dynamic loading are also investigated.
2.

Drywall Partition

2.1 General
The main role of the drywall partition is to provide
a space that is separated from noise and fire. The selected
type of the drywall partition, the light-gage steel-studframing system sheathed by gypsum boards, is the mostwidely used interior partition wall for all types ofbuilding in Japan. It consists of runners, studs, andgypsum boards. Runners and studs made of steel are theframing components of the wall. This type of drywall
partition is also commonly used in the United States ofAmerica for commercial buildings. However, design
details such as the thickness and the number of layers ofgypsum boards, and some of the installation procedures,are different from those of Japanese practice.
Two installation methods are available for theframing components. One is to install them in the ceiling,
and the other is to install them on the beam or the floorslab. In general, the first method is used for residentialbuildings, and the latter is used for office buildings andhospitals. In this study, the latter method is used to install
specimens. The following section describes theinstallation procedure of the drywall partition.
2.2 Installation of Drywall Partition
Before installing the drywall partition, base channels
are fixed to floors and beams by screws. Runners areattached to the floor and beam by screws to formhorizontal frames. A series of studs are attached torunners with a certain spacing (usually 450mm) to form
vertical frames.
The general procedure of installing the partition wall
is as follows:
1. Runners are bolted to the floor and beam (top andbottom beams, respectively, in the test).
2. Studs are attached to the runners to form verticalframes [Fig. 1(a)].

㧙㧙(c) the second layer(d) joint mixture
Fig. 1 Installation procedure.

Therefore, the drywall partition is expected not tosustain damage until the side of the drywall partition isconstrained by an intersecting wall or a structural column.
Such failure was observed in the tests, as explicatedbelow. Even though there is no code specification on theclearance of the drywall partition, 10-15mm is usuallyadopted in Japanese practice. On the other hand, it iscommon to fix steel studs to runners by screws in US
practice.
When installing a partition with a door, two verticalchannels are used to support the doorframe. Unlike studs,
these channels are securely fixed to runners by screws.
The clear spacing of the two channels equals the width ofthe doorframe so that the doorframe is fixed to thesechannels by screws.

The first (inner) layer of gypsum boards is attachedto studs by screws on each face of the drywall
partition [Fig. 1(b)].
4. The second (outer) layer of gypsum boards is
attached to the first layer of boards by glue andstaples [Fig. 1(c)] on each face of the drywall
partition.
5. Gaps between boards are sealed by the joint
mixture [Fig. 1(d)].
It is noted that studs are not screwed to runners, while thegypsum boards and studs are securely attached to eachother. When the building suffers story drift, e.g. by aseismic load, the studs and gypsum boards slide as
runners move with the floor or the ceiling.

2.3 Specimens
Four drywall partitions were built for the present
experimental study. Fig. 2 shows design details of these
specimens. Specimen No. 1 is a plain drywall partition
with the dimensions of 2800mm (height) by 3950mm(width), constructed with the procedure described in theprevious section. Specimen No. 2 is a drywall partition
with a door (850mm by 2100mm). The wall dimensions
are identical to those of specimen No. 1. Specimen No. 3
consists of two walls intersecting each other at a
90-degree angle. The width of the main wall (parallel tothe loading direction) is 2975mm and that of theintersecting wall (orthogonal to the loading direction) is
1600mm, while the height of both walls is 2800mm.

(a) studs

3.

(b) the first layer

Fig. 2 Design details of specimens (unit: mm).

㧙㧙Fig. 3 Test setup (unit: mm).
Specimen No. 4 was constructed to study the effect ofdynamic loading whose design is identical to Specimen
No. 1. For base channels, this study used JapaneseIndustrial Standard 65 type; for runner, WR-65(67X40X0.8); for stud, WS-65 (65X45X0.8); for stopperthat connects studs laterally, WB-25 (25X10X1.2). The
gypsum board whose dimensions are 910mm by
1820mm with 12.5mm thickness is made of gypsum andfinished with paper on one face.
3. Test Setup and Procedure
It is assumed that the most critical structural response
to partition walls is the story drift. Accordingly, the test
setup is designed such that pure shear loading, either
static or dynamic, is applied to the test specimen. Fig. 3
depicts the schematic of the test setup and its various
details. The specimen was mounted on pin-connectedbeams and columns such that base channels wereattached to the top and bottom beams. The clearance of
15mm between the drywall partition and the column wasprovided on each side (East and West) for all specimens
except Specimen No. 3 where it applied only to the eastside of the specimen. The hydraulic actuator wasconnected to the east column to provide the lateralloading.
Three rows of strain gauges were glued on one face(the north face) of the specimen to measure the strain of
the gypsum board in the vertical direction. For
Specimen No. 3, strain gauges were also glued on one
face (the east face) of the orthogonal panel in the same
pattern. One row was at the mid-height of the partition,
another was 250mm above the bottom runner, and thelast was 250mm below the top runner. The lateral space
between two adjacent strain gauges was 455mm. No
strain gauge was attached to the door panel in Specimen
No. 2.

Fig. 4 shows the sequence of quasi-static cyclicloading. It applies to all specimens except for Specimen
No. 4. After reaching the peak deformation of each cycle,
both positive and negative, and reaching zerodeformation, damage was inspected and recorded. A
series of sinusoidal loading, two cycles with the period of
1 second (one cycle) and the amplitude of 1/400, 1/200… and 1/10, the same as those specified in Fig. 4, wasapplied to specimen No. 4. At the end of each loading
amplitude, i.e., every two cycles, damage to thespecimen was inspected and recorded.

Fig. 4 Cyclic loading protocol.
4. Observations of Wall Damage
This section describes the damage to the specimens
observed by eyeball inspection, which is followed by the
analysis of strain measurements. Observed damage
patterns include crushing of boards, sealing cracks, board
cracks, and out-of-plane deformation of boards whoseparts around screws were crushed. Fig. 5 shows picturesof various damage patterns of the drywall partition.
4.1 Damage to Specimen No. 1
No damage was observed in Specimen No. 1 as longas the story drift did not exceed 0.01 rad. The partition
could slide without experiencing damage due to theconnection detail of studs and runners and the initial gaps
between the partition and the columns. The lateral rigid
movement of the partition by 15mm (initial gap of one

㧙㧙side) in addition to the initial gap of 15mm on the otherside prevented the partition from being damaged up to
30mm of the story drift that corresponds to 0.01 rad(30mm/2800mm). At 0.015 rad story drift, a room for thesliding was not available any more due to geometry andthe column started to crush the neighboring gypsum
board. Damage to the specimen is mainly due tocompressions from the columns and beams, rather than
the shear force. Fig. 6 shows a picture of Specimen No. 1
at the end of the last loading.

(a) crushingin which the values corresponding to peak rotations areplotted. The average strain of the boundary of thepartition is more than twice as high as that of the inside
up to the 0.06 rad story drift, where severe damage to the
gypsum boards fails some of the strain gauges at theboundary. Moreover, the average strain of the four
corners is about 50% higher than that of the boundary.
Damage to Specimen No. 1 is depicted in Fig. 8 where
the number in parentheses designates the loading
amplitude in radian at which the corresponding damage
occurs.

(b) board crack(c) sealing crack(d) board detachment
Fig. 5 Damage patterns.

Fig. 7 Average strains of Specimen No. 1.

Fig. 6 Specimen No. 1 after the test.
It is noted that the damage is concentrated at theboundaries of the partition, particularly the four corners,
while the inside portion of the partition only suffers from
relatively minor damage. To support this argument, theaverage strains of the inside portion, the boundary andthe four corners of the partition are compared in Fig. 7(a),4.2 Damage to Specimen No. 2
The feature of Specimen No. 2 is the door in thepartition. The functionality of the door is of interest as
well as damage to the partition for the safety issue.
During the test, the door was jammed at story drift of
0.01 rad. As shown in Fig. 9(a), the gap exists between
the door panel and the doorframe. At the story drift of
0.01 rad that causes 0.006 rad shear distortion of thedoorframe itself, the gap was closed because of therotation of the door panel to cause the door to jam, as
shown in Fig. 9(b). However, when the load wasremoved to the zero story drift, the door panel and thedoorframe recovered their original shapes and the door
was working. At the story drift of 0.02 rad, the door lockwas broken as well as the door jammed due to the door
panel’s rotation, as shown in Fig. 9(c). It was notrecovered even at the zero story drift and the door was
permanently jammed. It is noted that the shear distortionof the doorframe that caused this was 0.01 rad.

㧙㧙Fig. 8 Damage to Specimen No. 1.
the strain gauges at corners failed due to damage.
Moreover, the boundary of the partition shows 150%
higher strain than the inside. Damage to Specimen No. 2
is depicted in Fig. 12.

Fig. 9 Functionality of the door in the drywall
partition; (a) initial configuration of the door; (b)deformation of the door under 0.01 rad story drift; (c)deformation of the door under 0.02 rad story drift.

Fig. 11 Average strains of Specimen No. 2.

Fig. 10 Specimen No. 2 after the test.
Fig. 10 shows a picture of Specimen No. 2 after the
test. It is clearly visible that the entire partition iscompletely divided into three panels by cracks: the left,
above, and right side of the door. Fig. 11 shows thecomparison of the average strains of the inside, boundary,and corners of the partition. Similar to Specimen No. 1,
the corners suffer from higher strain than the other part ofthe partition up to the story drift of 0.02 where some of

4.3 Damage to Specimen No. 3
The feature of Specimen No. 3 is an intersecting partition.
The partition perpendicular to the loading direction isreferred to as the orthogonal partition. The parallel (to theloading direction) partition did not show any significant
damage up to story drift of 0.06 rad. At the next loading
cycle (0.08 rad story drift) some of the gypsum boards
were completely detached from studs and all the gypsum
boards of the north face of the partition fell completely tothe floor at the last loading cycle (0.1 rad). Fig. 13 shows
the damage to Specimen No. 3. The damage to theorthogonal partition is relatively small. This is verified by
the analysis of strain measurements.

㧙㧙

Fig. 12 Damage to Specimen No. 2.

Fig. 13 Specimen No. 3 after the test.

Fig. 14 Average strains of Specimen No. 3.

Fig. 15 Damage to Specimen No. 3.
Fig. 14 shows average strains of the parallel andorthogonal partitions. It should be noted that strain
measurements near the intersection of the two partitions
are excluded in the computation of the average strains.
The average strain in the parallel partition is twice ashigh as that in the orthogonal partition. Damage toSpecimen No. 3 is depicted in Fig. 15.

4.4 Damage to Specimen No. 4
A series of dynamic loads, as described in a preceding
section, is applied to Specimen No. 4, which is identicalto Specimen No. 1 in design. Unlike the tests of the otherspecimens, damage inspection was carried out at the endof each loading cycle (two dynamic cycles with the same㧙㧙

amplitude of the story drift). The damage pattern issimilar to that of Specimen No. 1 where the boundary of
the partition is more damaged than the inside of thepartition. Moreover, two gypsum boards werecompletely detached from the studs and fell to the floor.
Fig. 16 shows average strains of the boundary, inside,and four corners of the partition. The trend of the plot iscomparable to that of Specimen No. 1 in Fig. 7. A
picture of Specimen No. 4 at the end of the test is shownin Fig. 17. Damage to Specimen No. 4 is depicted in Fig.
18.
Fig. 17 Specimen No. 4 after the test.

Fig. 16 Average strains of Specimen No. 4.
5. Repair Cost Estimate
Throughout the series of loading tests, drywall partitions
experts (manufacturers) were present at the test site andevaluated damage of the partitions at different loadinglevels. In addition, they provided opinions on whether
the partitions should be repaired or replaced, if not intact.
The relationship between the story drift and the damage
to the partition in terms of the repair cost is developed.

Fig. 19 shows the ratio of the repair cost to the initialcost (referred to as the cost ratio) for Specimen Nos. 1, 2,
and 3 with respect to the story drift. The initial cost
includes two layers of gypsum boards, base steel frames,
runners and studs, and the labor expense. The repair costrefers to the cost to replace the damaged part of thepartition. It includes necessary material and labor
expenses to repair the partition and the removal anddisposal of the damaged part of the partition, so that the
replacement cost exceeds the initial cost. It is noted thatthe initial costs of Specimen Nos. 2 and 3 are 77% and
19% higher than that of Specimen No. 1, respectively.
Specimen No. 1 need not be repaired as long as thestory drift is not greater than 0.01 rad because it only slid
without being damaged. Therefore, at story drifts of
0.005 rad and 0.01 rad, which are considered the
expected demands for Levels 1 and 2 earthquakes inJapan, respectively, no repair was needed. At the story
drift of 0.02 rad, the cost ratio is already as high as 0.94.
At the story drift of 0.04, the repair cost exceeds theinitial cost. From the story drift of 0.015 to 0.04 rad, only

Fig. 18 Damage to Specimen No. 4.

㧙㧙gypsum boards are to be replaced. At the 0.06 rad story
drift, all parts except for the base steel frame are to be
replaced. After the 0.08 rad story drift, the whole wallneeds to be replaced and the cost ratio is 2.36.

without being damaged due to the sliding of the partition,
while the other specimens required repair at smaller story
drifts than 0.01 rad because sliding was not allowed forthem. After experiencing the 0.02 rad story drift, therepair cost almost reaches the initial cost of the partition
where the average cost ratio of three specimens is 0.86.
After the 0.08 rad story drift, the repair cost of all
specimens reaches their replacement costs except forSpecimen No. 3 where 98% of its replacement cost isrequired. The replacement costs of three specimens areabout twice the initial costs where the average cost ratiois 2.1.
6. Load-Displacement RelationshipFig. 19 Damage-repair cost relationship.
Specimen No. 2 need not be repaired as long as thestory drift is not greater than 0.005 rad. Some cracks
were observed at the story drift of 0.005, but they wereconsidered insignificant and not requiring repair. At thestory drift of 0.01 rad, the cost ratio is 0.43. The cost ratio
is 0.79 at the story drift of 0.02 rad, which includes thereplacement of the doorknob. At the story drift of 0.04
rad, the repair cost exceeds the initial cost. After the 0.04
rad story drift, the door needs to be replaced, whichcauses an additional rise in the repair cost. It is noted that
50% of the initial cost of this specimen is the installationof the door. After the 0.06 rad story drift, the wholepartition needs to be replaced and the cost ratio is 1.84.
Specimen No. 3 needs to be repaired as long as thestory drift is greater than 0.0025, which is earlier thanany other specimen. This is caused by the damage to
gypsum boards and joint mixtures near the intersectionof the parallel and orthogonal partitions. At the story drift
ratios of 0.005 rad and 0.01 rad, the cost ratios are 0.08
and 0.24, respectively. At the story drift of 0.02 rad, thecost ratio is 0.85. From the 0.02 to 0.04 rad story drift,
the orthogonal partition also needs to be repaired. From
the 0.06 rad story drift where the repair cost exceeds theinitial cost, almost all parallel partition needs to be
repaired. However, this specimen does not require thewhole replacement of the partition whose cost ratio is2.02 because some parts of the orthogonal partition areintact.
Overall, none of the specimens needs to be repaired
as long as the story drift is not greater than 0.0025 rad.
Specimen No. 1 could take the story drift of 0.01 rad

During the test, the load in the jack and thecorresponding displacement that is under control aremeasured to investigate the load-displacement
relationship of the specimen. The relationship between
the story shear force and story drift for each specimen isshown in Fig. 20. The most important characteristics ofthe load-displacement relationship are pinching andstiffness degradation. Strength degradation is also
observed in all three specimens where those of Specimen
No. 1 in the negative loading and of Specimen No. 3 inthe positive loading direction are distinctive.
The shear strengths, regardless of the direction ofloading, are 72, 50 and 51 kN for Specimen Nos. 1, 2,
and 3, respectively. These strengths do not seem
negligible with respect to the structural strength expected
for steel moment frames. For example, a wide-flangecross-section typically used in Japan for low to
medium-rise steel moment frames, H-300x300x10x15,
has a share capacity of about 250 kN in the strong axis
bending. (Here, assumed was a column height of 4m,
steel’s yield stress of 300 MPa, and formation of plastic
hinges at both ends of the column in double curvature
bending.) The partitions’ shear strengths reach greaterthan 20% the column shear capacity. In light of thedamage pattern of the tested partitions, the source of theload-resisting mechanism of the partition is believed tobe the compressive resistance of gypsum boards nailed tostuds. The lateral resistance provided by partitions is ofa great interest in the characterization of the ultimate
resistance of steel frames. The information obtained
from this study is still limited, and further examinations
are needed for this purpose, including theoreticalverifications of the load-resisting mechanism.

㧙㧙(a) Specimen No. 1(b) Specimen No. 2(c) Specimen No. 3(d) Specimen No. 4
Fig. 20 Story shear force vs. story drift relationships.
The load-displacement relationships of all three
specimens are not symmetrical with respect to theloading direction. As shown in Fig. 20(a), peak strengths
in the positive loading direction at each loading cycle arehigher than the counterparts in the negative direction forSpecimen No. 1. Moreover, the strength degradation in
the negative direction is more severe than that in thepositive direction. It is partially attributed to the notionthat gypsum boards damaged in positive loading do not
fully contribute to the corresponding load-carrying
capacity in the negative direction.
For Specimen No. 2, peak strengths in the positive

loading direction at each loading cycle are lower thantheir counterparts in the negative direction as shown in
Fig. 20(b). In the positive loading, gypsum boards on theeastern side of the door act as the load-resisting
component because the doorframe is fixed to the basechannel and serves as the bearing support to the partition
as shown in Fig. 21(a). On the other hand, when the load
is reversed, gypsum boards on the western side of thedoor play the same role [Fig. 21(b)]. The difference inthe bearing area at the bottom of the wall (1250mm and
1800mm for the positive and negative loadings,
respectively) is likely to have caused the difference in theFig. 21 Load-resisting mechanism of Specimen No. 2.

㧙㧙peak strength. Severe strength degradation is notobserved, because the doorframe always acts as thebearing support in both directions.
Due to the design detail, the stud at the intersectionof the two walls is fixed to the top and bottom runners
for Specimen No. 3. In the positive loading, this stud
tries to prevent the parallel partition from sliding.
However, the gypsum boards and the other studs still
manage to slip a small amount (relative to the cases ofthe other two specimens), because some parts of the
gypsum boards are detached from the fixed stud. The
increase in the amount of sliding due to the increase of
the loading causes the strength degradation in thepositive direction. On the other hand, when the load isreversed, the gap between the parallel partition and theeastern steel column is large enough not to be closed at
the peak load of each cycle. Therefore the strength in thenegative direction stays relatively low.
Fig. 20(d) for Specimen No. 4 shows inertial effectof the steel frame where the story shear force is increased
when the loading direction is changed. However, it does
not affect the damage of the wall as described earlier.

Repair cost estimates based on damage observations
provide important quantitative information in the context
of performance-based earthquake engineering. In theplain partition, damage and the consequent repair were
avoided due to the loose connection between studs andrunners up to the story drift of 0.01 rad. For all partitions,at the story drift ratio of 0.02 rad, the repair costs almost
reach the initial costs of drywall partitions while they are
twice as much as the initial costs at 0.08 rad story drift
ratio. It confirms the importance of drywall partitions to
the loss estimate of a building under seismic loadings.
In large drift angles, the tested partitions sustain
shear resistance, which may not be negligible. The
resistance may not be smaller than 20% of the structuralresistance of steel moment frames. This statement,
however, is preliminary, requiring more detailed research
about the load-resisting mechanism of drywall partitions.
The experimental project described in this paper is stillongoing, having been extended to tests of exterior
cladding and window glasses, which will be reported
later.
Acknowledgements

7. Conclusions and Future Extensions
Seismic performance of interior drywall partitions is
experimentally evaluated and the corresponding repair
cost is estimated. Four full-scale drywall partitions withlight-gage steel stud framing sheathed with two layers ofgypsum boards on both faces are constructed according
to common Japanese building practice. Three different
configurations of drywall partitions, namely plain
partition, partition with a door, and partition with anintersecting wall, are considered to investigate the effectof design details on the behavior under quasi-static cyclicloadings, while the effect of the dynamic loading isinvestigated for the case of the plain partition.
Under the pure shear loading that simulates the story
drift of the building, damages to drywall partitions areconcentrated at perimeters where they are restrained byadjacent columns and beams or fixed studs for special
configurations, such as a door and an intersecting wall.
This implies that the design details affect the damage ofthe drywall partition. The test of the drywall partition
with a door revealed that a door might jam at a relatively
low story drift ratio (e.g. 2% radian). Dynamic loading
effect on the damage of the drywall partition is
negligible.

This study was conducted as part of the
NEES/E-Defense Cooperative Project sponsored by theUnited States National Science Foundation and theJapanese Ministry of Education, Culture, Sports, Scienceand Technology. This study was also conducted as partof a research project supported by Grant-in-Aid for
Scientific Research (Basic Research Category S – No.
14102028) and administered by the Japan Society for the
Promotion of Science. The fifth author was the principal
investigator of this project. The Twenty-First Century
Center of Excellence (COE) Program awarded to theDisaster Prevention Research Institute, Kyoto University(Grant No. 14219301) supported the employment of thefirst author. The authors express their gratitude for thesponsorship.
References
Adhams, S. A., Anderson, R. W., Elmlinger, J., andGregory, J. (1990): Shear wall resistance of lightgage
steel stud wall systems, Earthquake Spectra, EERI, Vol.
6, No. 1, pp. 1-14.
Filiatrault, A., Uang, C.-M., Folz, B., Christopoulos, C.,
and Gatto, K. (2001): Reconnaissance report of the㧙㧙Roorkee, Meerut, India, Nov. 10-12, S. Prakashan, ed.,Vol. 1, pp. 267-277.
Rihal, S. S., Freeman, S. A., Gates, W., and Sabol, T.
(1998): Lessons and seismic design implications of
non-structural component damage during the 1994
Northridge earthquake – selected case studies,
Proceedings of the NEHRP Conference and Workshop
on Research on the Northridge Earthquake of Jan. 17,
1994, Vol. 3-8, CUREe, Richmond, CA., pp. 429-440.
Serrette, R. and Ogunfunmi, K. (1996): Shear resistanceof gypsum-sheathed light-gauge steel stud walls,
Journal of Structural Engineering, ASCE, Vol. 122, No.
4, pp. 383-389.
Shephard, R. B., Wood, P. R., Berill, J. B., Gillon, N. R.,
North, P. J., Perry, A. K., and Bent, D. P. (1990): The
Loma Prieta, California, Earthquake of October 17,
1989 – Report of the NZNSEE Reconnaissance team,
Bulletin of the New Zealand National Society for
Earthquake Engineering (NZNSEE), Vol. 23, No. 1.
Taghavi, S. and Miranda, E. (2003): Response
assessment of nonstructural building elements, PEER
Report 2003/05, The Pacific Earthquake Engineering
Research Center, Berkeley, CA.
Villaverde, R. (1997): Seismic design of secondary
structures: state of the art, Journal of StructuralEngineering, ASCE, Vol. 123, No. 8, pp. 1011-1019.

February 28, 2001 Nisqually (Seattle-Olympia)
earthquake, Structural Systems Research Project Report
SSRP-2000/15, Dept. of Structural Engineering,
University of California, San Diego, La Jolla, CA.
Freeman, S. A. (1977): Racking tests of high-risebuilding partitions, Journal of Structural Division,
ASCE, Vol. 103, No. 8, pp. 1673-1685.
Hall, J. F. (1995): “Nonstructural damage”, Northridge
earthquake of January 17, 1994 reconnaissance report,
Earthquake Spectra, Publication 95-03, Vol. 1, pp.
453-513.
Hirakawa, N. and Kanda, J. (1997): Estimation of failure
costs at various damage states, Summaries of TechnicalPapers of Annual Meetings of Architectural Institute ofJapan, B-1, Kanto, pp. 75-76 (in Japanese).
Liew, Y. L., Duffield, C. F., and Gad, E. F. (2002): The
influence of plasterboard clad walls on the structural
behavior of low rise residential buildings, Electronic
Journal of Structural Engineering, Vol. 2, pp. 1-6.
McMullin, K. M. and Merrick, D. S. (2005): Seismic
damage thresholds for gypsum wallboard partition
walls, Journal of Architectural Engineering, ASCE
(accepted).
Rihal, S. S. (1982): Behavior of non-structural building
partitions during earthquakes, Proceedings of 7th
Symposium on Earthquake Engineering, University of㕖᭴ㅧㇱ᧚ߩ⠴㔡ᕈ⢻⹏ଔ㧦㑆઀ಾო.GG6CG*[WPI࡮ട⊓⟤༑ሶ ࡮᧻ችᥓᄩ࡮็↰໪৻㇢࡮ਛፉᱜᗲ
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