FEDERAL EMERGENCY MANAGEMENT AGENCY FEMA 741 September 1994 
Supersedes 1985 Edition 
Reducing the Risks 
of Nonstructural 
Earthquake Damage 
A PRACTICAL GUIDE 
Issued by FEMA in furtherance of the Decade for Natural Disaster Reduction 
Reducing the Risks of
Nonstructural Earthquake Damage 
A Practical Guide 
Third Edition 
FEAIA 74/September 1994 
Supersedes 1985 Edition 
Originally developed by Robert Reitherman of Scientific Service, Inc., for the 
Southern California Earthquake Preparedness Project (SCEPP) 
Third Edition by 
WISS, JANNEY, ELSTNER ASSOCIATES, INC. 
For the Federal Emergency Management Agency (FEMA) 
Under the National Earthquake Technical Assistance Contract (NETAC) EMW-92-C-3852 
Authors: Advisory Panel: 
Eduardo A. Fierro Christopher Arnold Richard Eisner 
Cynthia L. Perry William Holmes Robert Reitherman 
Sigmund A. Freeman 
TABLE OF CONTENTS 
LIST OF FIGURES V 
PREFACE vi 
1. HOW TO USE mrs GUIDE 
PURPOSE 1 
INTENDED AUDIENCE 1 
LIMITATIONS 2 
CHAPTER CONTENTS 2 
2. OVERVIEW 
DEFINITIONS 4 
SIGNIFICANCE OF NONSTRUCTURAL DAMAGE 4 
CAUSES OF NONSTRUCTURAL DAMAGE 12 
METHODS FOR REDUCING NONSTRUCTURAL HAZARDS 15 
BUILDING CODE REQUIREMENT FOR NONSTRUCTURAL COMPONENTS 16 
SEISMIC HAZARD 18 
3. NONSTRUCTURAL SURVEY PROCEDURES 
TYPICAL NONSTRUCTURAL COMPONENTS 21 
FACILITY SURVEY 21 
ASSESSMENT PROCEDURES 22 
COMPARISON OF ALTERNATIVES 25 
4. NONSTRUCTURAL EXAMPLES: EARTHQUAKE DAMAGE 
AND UPGRADE DETAILS 
NONSTRUCTURAL EXAMPLES 26 
BUILDING UTILITY SYSTEMS 
Batteries and Battery Rack 30 
Diesel Fuel Tank 31 
Electrical Bus Ducts and Primary Cable System 32 
Fire Extinguisher 33 
Propane Tank 34 
Water Heater: Corner Installation 35 
Water Heater: WallInstallation 36 
Piping 37 
Chiller 38 
Air Compressor (or other WAC Equipment) 40 
Suspended Space Heater 41 
WAC Distribution Ducts 42 
Air Diffuser 43 
Residential Chimney 44 
Built-kn Partial-Height Partitions 45
Built-k Full-Height Partitions 46
Suspended T-Bar Ceilings 47 
Suspended Light Fixtures 48 
Pendant Light Fixtures 49
Stairways 50 
Windows 51
Unreinforced Brick Parapets 52 
Veneer 53
Freestanding Walls or Fences 54 
Exterior Signs 55
FURNITURE AND CONTENTS 
Large Computers and Access Floors 56 
Desktop Computers and Office Equipment 57
Tall Shelving: Freestanding 58
Library Stacks 59 
Tall Shelving: Wall Unit 60 
Tall File Cabinets 61
Flexible Connection for Gas or Fuel Lines 62 
Drawer and Cabinet Latches 63
Freestanding Wood Stove 64 
Compressed-Gas Cylinders 65 
Containers of Hazardous Materials 66
Fragile Artwork 67 
Freestanding Half-Height Partitions 68 
Miscellaneous Furniture 69
INSTALLATION NOTES 70
5. DEVELOPING EARTHQUAKE PROTECTION PROGRAMS 
SELF-HELP VS. USE OF CONSULTANTS 76
IMPLEMENTATION STRATEGIES 77
EVALUATION 79
6. EMERGENCY PLANNING GUIDELINES 
IMPLICATIONS OF NONSTRUCTURAL DAMAGE 
FOR EMERGENCY PLANNING 81
EARTHQUAKE PLANS 82 
TRAINING 83
EXERCISES :84 
PERSONAL EMERGENCY KITS 84
MASTER EARTHQUAKE PLANNING CHECKLIST 84 
7. FACILITIES DEVELOPMENT GUIDELINES 
NONSTRUCTURAL CONSTRUCTION GUIDELINES 87 
STRUCTURAL/NONSTRUCTURAL INTERACTION 89 
ARCHITECTURAL ELEMENTS 
FEES FOR PROFESSIONAL SERVICES 90
GLOSSARY 91
REFERENCES 93
ANNOTATED BIBLIOGRAPHY 95
B: CHECKLIST OF NONSTRUCTURAL EARTHQUAKE HAZARDS B-1
C: NONSTRUCTURAL RISK RATINGS C-1
APPENDIXES 
A: NONSTRUCTURAL INVENTORY FORM A-i 
LIST OF FIGURES
Page1. Nonstructural and Structural Components of a Typical Building 5
2. Examples of Hazardous Nonstructural. Damage 6
3. Examples of Hazardous Nonstructural Damage 8
4. Examples of Property Loss Due to Nonstructural Damage 10
5. Examples of Loss of Function Due to Nonstructural Damage 11
6. Effects of Earthquakes on Nonstructural Components 14
7. Map of Probable Shaking Intensity for the United States 19
8. Nonstructural Examples 28-29 
9. Information Gathering Checklist: Organizational Characteristics 85
10. Master Nonstructural Earthquake Protection Checklist 86
PREFACE
The first edition of this guide was prepared 
under contract to the Southern California 
Earthquake Preparedness Project (SCEPP), a 
joint state-federal effort. It was prepared by 
Scientific Service, Inc., a firm specializing in 
engineering and emergency planning consulting 
related to natural and man-made hazards. It 
was written and researched by Robert 
Reitherman with the assistance of Dr. T. C. 
Zsutty; they provided architectural and 
structural engineering expertise, respectively, in 
the field of nonstructural earthquake damage. 
The second edition was published in 1985 by 
the Bay Area Regional Earthquake Preparedness 
Project, now part of the California Office of 
Emergency Services, Earthquake Program. 
Revisions were based on the suggestions of 
users and a peer review committee consisting of 
Christopher Arnold, president, Building Systems 
Development, Inc.; Richard Eisner, director of 
BAREPP; Eric Elsesser, vice president, 
Forell/Elsesser; William Holmes, structural 
engineer, Rutherford & Chekene; John Meehan, 
chief, structural safety, Office of the State 
Architect; and Gilbert Najera, Southern 
California Earthquake Preparedness Project. 
The revisions made in the second edition of the 
guide consisted primarily of modifying graphics, 
updating construction cost estimates, and 
identifying the need for engineering and 
architectural assistance in designing and 
carrying out the guide's recommendations. 
This third edition was prepared by Wiss, 
Janney, Elstner Associates, Inc., for the Federal 
Emergency Management Agency (FEMA) under 
the National Earthquake Technical Assistance 
Contract (EMW-92-C-3852). The objective of 
this revision is to incorporate lessons learned 
from earthquakes that have occurred since the 
second edition was published, provide additional 
details, distinguish between do-it-yourself details 
and those for which there is additional 
engineering required, update the cost estimates 
presented, and incorporate new techniques and 
trends in earthquake engineering. The format of 
the document has been substantially revised. 
Review comments and suggestions were 
provided by the advisory panel, which was 
composed of Christopher Arnold, Richard 
Eisner, William Holmes, and Robert 
Reitherman. 
Individual photo credits are provided, both for 
photos carried over from previous editions and 
for those new to the third edition. Some new 
anchorage or bracing details have been adapted 
from other publications that are listed in the 
References (References 16 to 21). 
Disclaimer FEMA and Wiss, Janney, Elstner 
Associates have attempted to produce reliable 
and practical information in this publication, but 
neither they nor any consultants involved in 
preparing or reviewing material contained in 
this guide can guarantee that its application will 
safeguard people or property in case of an 
earthquake. The state of the art of earthquake 
engineering is not sufficiently developed to 
perfectly predict the performance of 
nonstructural elements or to guarantee adequate 
earthquake protection if these or other 
guidelines are followed. Professional expertise 
is recommended to increase the probability that 
intended levels of earthquake protection will be 
achieved. Liability for any losses that may 
occur in an earthquake or as a result of using 
this guidance is specifically disclaimed. 
HOW TO, USE THIS GUIDE 
PURPOSE 
This guide was developed to fulfill several 
different objectives and address a wide audience 
with varying needs. The primary intent is to 
explain the sources of nonstructural earthquake
damage in simple terms and to provide 
information on effective methods of reducing 
the potential risks. The recommendations 
contained in this guide are intended to reduce 
the potential hazards but cannot completely 
eliminate them. 
INTENDED AUDIENCE 
This guide is intended primarily for use by a lay 
audience: building owners, facilities managers, 
maintenance personnel, store or office 
managers, corporate/agency department heads, 
business proprietors, homeowners, etc. Some 
readers may be small-business owners with a 
small number of potential problems that could 
be addressed in a few days' time by having a 
handyman install some of the generic details 
presented in this guide. Other readers may be 
responsible for hundreds of facilities and may 
need a survey methodology to help them 
understand the magnitude of their potential 
problems. 
The purpose of this section is to help readers 
identify those portions of the guide that may be 
applicable to their particular situation and 
interests. The prospective audience can be 
subdivided into the four general categories 
described below. Each description contains a 
list of the chapters that may be the most useful 
for that group of readers. The chapter contents 
are also described below. 
General Interest The lay reader who wants 
an illustrated overview of the subject of 
nonstructural earthquake damage. 
Suggested reading for the 
genera interest reader: 
Chapters 1and 2 and the 
nonstructured examples in 
Chapter 4.
Do-It-Yourself The reader who wants a 
general overview of the subject, help in 
identifying potential hazards, and specific 
guidance with suggested upgrade derails that the 
reader can implement him-or herself. 
Suggested reading for the 
do-it-your self reader: 
Chapters 1, 2, 3, and 4. 
Chapter 4 contains some 
generic details and 
installation guidelines. 
Facilities/Planning Personnel Facilities 
or planning personnel who need an overview of 
the subject as well as a survey methodology 
applicable to an organizational setting. This 
guide contains forms and checklists that can be 
used to survey a facility to identify potential 
hazards, estimate seismic vulnerability and 
potential earthquake losses and repair costs, and 
estimate the costs in implementing hazard 
reduction methods. The guide differentiates 
between methods that can be readily 
implemented by a handyman and those that 
require professional assistance. The guide also 
contains a discussion of various implementation 
strategies and general guidance on earthquake 
preparedness and emergency planning. 
Architect/Engineer The A/E who has little 
or no knowledge of nonstructural earthquake 
damage and needs an introduction to the subject 
and a list of sources that will provide more 
detailed technical information. 
The categories and suggested reading above are 
intended to be helpful, not restrictive. Readers 
are encouraged to use this guide and/or adapt 
the forms and checklists herein in any way that 
is helpful to their particular circumstances. 
Self-diagnosis and self-implementation by the 
nonengineer may be adequate in many instances, 
and an attempt has been made to provide 
enough detail to allow for complete 
implementation of some of the simpler 
protective measures. However, there are limits 
to the self-help approach, as explicitly stated 
below. 
Limitations
If this were a guide that explained how a person 
could administer his or her own physical exam, 
diagnose any health problems, and prescribe and 
carry out the appropriate treatment, certain 
obvious questions would arise: How far along 
that path can an untrained person proceed before 
requiring the services of a physician? Wouldn't 
the layperson get into trouble trying to practice 
self-help medical care?
When in doubt, consult a civil or structural engineer. 
There are similar limitations 
And caveats that must be 
made explicit in this 
guide's attempt to 
instruct laypersons in self-help earthquake 
engineering. In addition to the individual notes 
found later, which point out specific areas 
where expertise is required, the general 
disclaimer should be made here that the use of 
earthquake engineering expertise is often 
desirable to improve the reliability of identifying 
and reducing earthquake risks. When in doubt 
about a health problem, consult a doctor. When 
in doubt about the "seismic health" of a facility, 
consult a civil or structural engineer, or an 
architect. On the other hand, many self-help 
techniques are commonly recommended by 
doctors, such as taking one's temperature, 
treating minor colds with commonsense 
measures rather than costly trips to the doctor, 
managing one's diet with only occasional 
professional advice, and so on. Similarly, this 
guide attempts to provide advice for self-help 
earthquake protection measures and presumes 
that the advice will be applied wisely and that 
expert assistance will be obtained where 
necessary. 
CHAPTER CONTENTS 
The material in this book is organized as 
follows. 
Chapter 1 -How to Use This Guide 
Information to help readers with different 
interests find the relevant portions of this guide. 
Chapter 2 Overiew
General discussion
of the problems associated with nonstructural 
earthquake damage. 
Chapter 3 -Survey and Assessment 
Procedures Guidelines on how to survey the 
nonstructural items in a facility and assess the 
vulnerability of these items to earthquake 
damage. The appendixes contain inventory 
forms and detailed checklists with information 
designed to help identify vulnerable items. 
Chapter 4 Nonstructural Examples: 
Earthquake Damage and Upgrade 
Details Examples for selected nonstructural 
items. -Each example typically includes a 
photograph showing earthquake damage to an 
unanchored or inadequately anchored item and 
suggested upgrade details that can be used to 
reduce the seismic vulnerability of such items. 
Some of the simpler details in this chapter are 
marked Do-It-Yourself and can be installed by a 
handyman following the installation guidelines 
contained in the text. The details marked 
Engineering Required are schematic only, and 
design professionals should be retained to 
evaluate these systems and develop appropriate 
upgrade details. The design of upgrade details 
to protect against earthquake damage to these 
items is complicated and requires specialized 
professional expertise. 
Chapter 5 -Developing an 
Earthquake Protection Program A 
discussion of various implementation strategies: 
whether to use existing staff or outside 
consultants; whether to embark on an ambitious 
upgrade program or combine the upgrades with 
ongoing maintenance or remodeling; how to 
evaluate the success of a program. 
Chapter 6 -Emergency Planning 
Guidelines A discussion of emergency 
response planning, that is, how to include 
potential damage to nonstructural components in 
an emergency plan. Have emergency exits been 
designated that do not have glass, veneer, or 
heavy canopies that are vulnerable to damage? 
Who is responsible for shutting off the water 
and gas if the pipes break, and is that person--
and an alternate--available 24 hours a day? 
Does the organization provide training for 
employees on what to do in an earthquake? 
Chapter 7 -Facilities Development 
Guidelines For essential facilities and/or 
large organizations. In these cases, it may be 
appropriate to develop formal construction 
guidelines or specifications for the installation of 
nonstructural components. Such guidelines 
might include a statement of the desired 
performance for particular equipment, 
requirements for inspection during construction, 
or specification of a particular design code or 
force level to be used in the design of 
equipment anchorage. 
Glossary Earthquake engineering terms used 
in this guide. 
References References cited in the text. 
Annotated Bibliography Additional 
references that may be useful to architects, 
engineers, or others seeking more detailed 
information about this topic. 
Appendix A -Nonstructural Inventory 
Form 
Appendix B -Checklist of 
Nonstructural Earthquake Hazards 
Appendix C -Nonstructural Risk 
Ratings 
2. OVERVIEW
The primary focus of this guide is to help the 
reader understand which nonstructural items are 
most vulnerable in an earthquake and most 
likely to cause personal injury, costly property 
damage, or loss of function if they are 
damaged. In addition, this guide contains 
recommendations on how to implement cost-
effective measures that can help to reduce the 
potential hazards. 
DEFINITIONS 
At the outset, two terms frequently used in the 
earthquake engineering field should be defined. 
Structural The structural portions of a 
building are those that resist gravity, 
earthquake, wind, and other types of loads. 
These are called structural components and 
include columns (posts, pillars); beams (girders, 
joists); braces; floor or roof sheathing, slabs, or 
decking; load-bearing walls (i.e., walls designed 
to support the building weight and/or provide 
lateral resistance); and foundations (mat, spread 
footings, piles). For buildings planned by 
design professionals, the structure is typically 
designed and analyzed in detail by a structural 
engineer. 
Nonstructural The nonstructural portions of 
a building include every part of the building and 
all its contents with the exception of the 
structure--in other words, everything except the 
columns, floors, beams, etc. Common 
nonstructural components include ceilings; 
windows; office equipment; computers; 
inventory stored on shelves; file cabinets; 
heating, ventilating, and air conditioning 
(HVAC) equipment; electrical equipment; 
furnishings; lights; etc. Typically, nonstructural 
items are not analyzed by engineers and may be 
specified by architects, mechanical engineers 
(who design HVAC systems and plumbing for 
larger buildings), electrical engineers, or 
interior designers; or they may be purchased 
without the involvement of any design 
professional by owners or tenants after 
construction of a building. Figure 1 identifies 
the structural and nonstructural components of 
a typical building. Note that most of the 
structural components of a typical building are 
concealed from view by nonstructural materials. 
SIGNIFICANCE OF 
NONSTRUCTURAL DAMAGE 
Why is nonstructural earthquake damage of 
concern? What are the direct effects of damage 
to nonstructural items? What are the secondary 
effects or potential consequences of damage? 
The following discussion covers three types of 
risk associated with earthquake damage to 
nonstructural components: life safety, property 
loss, and interruption or loss of essential 
functions. Damage to a particular nonstructural 
item may have differing degrees of risk in each 
of these three categories. In addition, damage 
to the item may result in direct injury or loss, 
or the injury or loss may be a secondary effect 
or consequence of the failure of the item. 
LS Life Safety 
The first type of risk is 
that people could be injured or killed by 
damaged or falling nonstructural components. 
Even seemingly innocuous items can be lethal if 
they fall on an unsuspecting victim. If a 
25-pound fluorescent light fixture not properly 
fastened to the ceiling breaks loose during an 
earthquake and falls on someone's head, the 
potential for injury is great. Examples of 
potentially hazardous nonstructural damage that 
AIR CONDITIONING 
ELECTRICAL 
DUCT. BEAM 
CONDUIT FOR 
WIRING. HAPNGER WIF AIR 
FIRE 
EXTERIOR 
SUSPENDED CURTAIN WALL, 
CEILING WINDOWS, 
ACOUSTICAL CLADDING. 
TILE. 
STEEL OR 
CONCRETE 
COLUMNS. 
KEY 
WALL.
PARTITION 
REINFORCED 
CONCRETE SLAB 
ON METAL DECK OR 
CONCRETE SLAB. 
COLUMN (STEEL 
COLUMN SHOWN... 
USUALLY ENCASED 
IN NONSTRUCTURAL 
FIREPROOFING). 
KEY
Figure 1  Nonstructural and Structural Components of a Typical Building
NONSTRUCTURAL ITEMS (STANDARD TEXT) 
STRUCTURAL ITEMS (ITALICS) 
Failure of office partitions, ceilings, and light fixtures 
Earthquake Damage: 1994, Northridge, California 
Photo Credit: Wiss, Janney, Elstner Associates, Inc. 
Shard of broken nontempered glass that fell several stories from a multistory building 
Earthquake Damage: 1994, Northridge, California 
Photo Credit: Wiss, Janney, Elstner Associates, Inc. 
Figure 2 -Examples of Hazardous Nonstructural Damage 
has occurred during past earthquakes include 
broken glass, overturned tall and heavy cabinets 
or shelves, falling ceilings or overhead light 
fixtures, ruptured gas lines or other piping 
containing hazardous materials, damaged friable 
asbestos materials, falling pieces of decorative 
brickwork or precast concrete panels, and 
collapsed masonry walls or fences. (Figures 2 
and 3). 
Several specific examples will help to illustrate 
the point. 
* More than 170 campuses in the Los Angeles 
Unified School District suffered damage--most 
of it nonstructural--during the 1994 Northridge 
earthquake. At Reseda High School, the ceiling 
in a classroom collapsed and covered the school 
desks with debris. The acoustic ceiling panels 
fell in relatively large pieces, approximately 3 
feet or 4 feet square, accompanied by pieces of 
the metal ceiling runners and funl-length sections 
of strip fluorescent light fixtures. Because the 
earthquake occurred at 4:31 a.m., when the 
building was unoccupied, none of the students 
were injured [1]. 
* A survey of elevator damage following the 
1989 Loma Prieta earthquake revealed 98 
instances where counterweights came out of the 
guide rails and 6 instances where the 
counterweight impacted the elevator cab, 
including one case where the counterweight 
came through the roof of the cab. Fortunately, 
no injuries were reported [2]. 
* One hospital patient on a life-support system 
died during the 1994 Northridge earthquake 
because of failure of the hospital's electrical 
supply [3]. 
* During the 1993 Guam earthquake, the fire-
rated nonstructural masonry partitions in the exit 
corridors of one resort hotel were extensively 
cracked, causing many of the metal fire doors in 
the corridors to jam. Hotel guests had to break 
through the gypsum wallboard partitions 
between rooms in order to get out of the 
building, a process that took as long as several 
hours. It was fortunate that the earthquake did 
not cause a fire in the building, and no serious 
injuries were reported. 
PL Property Loss For most 
commercial buildings, the foundation and 
superstructure account for approximately 2025 
% of the original construction cost, while the 
mechanical, electrical, and architectural 
elements account for the remaining 75-80%. 
Contents belonging to the building occupants, 
such as movable partitions, furniture, files, and 
office or medical equipment, represent a 
significant additional expense. Damage to the 
nonstructural elements and contents of a 
building can be costly, since these components 
account for the vast majority of building costs. 
Immediate property losses attributable to 
contents alone are often estimated to be one 
third of the total earthquake losses [4].. 
Property losses may be the result of direct 
damage to a nonstructural item or of 
consequential damage. As used here, the term 
property loss refers only to immediate, direct 
damage. If water pipes or fire sprinkler lines 
break, the overall property losses will include 
the cost to repair the piping plus the cost to 
repair water damage to the facility. If the gas 
line to a water heater ruptures and causes a fire, 
clearly the property loss will be much greater 
than the cost of a new pipe fitting. On the other 
hand, if many file cabinets overturn and all the 
contents end up on the floor, the direct damage 
to the cabinets and documents will probably be 
negligible (unless they are also affected by 
water damage), but employees may spend many 
hours or days refiling the documents. If a 
reserve water tank is situated on the roof of a 
building, the consequences of damage may be 
more severe than they would be if it were in the 
Failure of suspended ceiling and light fixtures in furniture store 
Earthquake Damage: 1994 Northridge California 
Photo Credit: William McKevitt
Failure of heavy stucco soffit at building entrance 
Earthquake Damage: 1994, Northridge, California 
Photo Credit: Robert Reitherman 
Figure 3 -Examples of Hazardous Nonstructural Damage 
basement or outside the building in the parking 
lot. 
A few individual cases may help illustrate the 
potential for property loss. (See Figure 4). 
* A survey of 25 commercial buildings 
following the 1971 San Fernando earthquake 
revealed the following breakdown of property 
losses: structural damage, 3%; electrical and 
mechanical, 7%; exterior finishes, 34%; and 
interior finishes, 56%. A similar survey of 50 
high-rise buildings, which were far enough 
away from the earthquake fault to experience 
only mild shaking, showed that none had major 
structural damage but 43 suffered damage to 
drywall or plaster partitions, 18 suffered 
damaged elevators, 15 had broken windows, 
and 8 incurred damage to air conditioning 
systems [5]. 
Many offices and small businesses suffer losses 
as a result of nonstructural earthquake damage 
but may not keep track of these losses unless 
they have earthquake insurance that will help 
cover the cleanup and repair costs. The next 
examples, which are more dramatic, involve 
library and museum facilities whose function is 
to store and maintain valuable contents, where 
the nonstructural losses are easy to identify. 
* Following the 1989 Loma Prieta earthquake, 
two libraries in San Francisco each suffered 
over a million dollars in damage to building 
contents; the money was spent primarily on 
reconstructing the library stacks, rebinding 
damaged books, and sorting and reshelving 
books. At one of these facilities, $100,000 was 
spent rebinding a relatively small number of 
rare books [6, 7]. 
* A survey of eight museums in the San 
Francisco Bay Area following the 1989 Loma 
Prieta earthquake indicated that approximately 
150 out of more than 500,000 items had 
suffered some type of damage, resulting in 
losses on the order of $10 million. At the 
Asian Art Museum in San Francisco, with a 
collection estimated to, have a market value of 
$3 billion, damage to 26 items resulted in a total 
loss of $3 million, or roughly 1%. All eight of 
these facilities had implemented some form of 
seismic mitigation before the earthquake, and 
these measures prevented more serious losses 
[2, 8]. 
LF Loss of Function In addition to 
the life safety and property loss considerations, 
there is the additional possibility that 
nonstructural damage will make it difficult or 
impossible to carry out the functions normally 
accomplished in a facility. After the serious life 
safety threats have been dealt with, the potential 
for postearthquake downtime or reduced 
productivity is often the most important risk. 
Many external factors may affect postearthquake 
operations, including power and water outages, 
damage to transportation structures, civil 
disorder, police lines, curfews, etc. These 
effects are outside the control of building 
owners and tenants and hence outside the scope 
of this discussion. 
The following are examples of nonstructural 
damage that resulted in interruptions to 
postearthquake emergency operations or to 
business. 
* During the 1994 Northridge earthquake, 
nonstructural damage caused temporary closure, 
evacuation, or patient transfer at ten essential 
hospital facilities. These hospitals generally had 
little or no structural damage but were rendered 
temporarily inoperable, primarily because of 
water damage. At over a dozen of these 
facilities, water leaks occurred when fire 
sprinkler, chilled-water, or other pipelines 
broke. Hospital personnel were apparently 
unavailable or unable to shut off the water, and 
Complete loss of suspended ceiling and light fixtures 
Earthquake Damage: 1994, Northridge, California 
Photo Credit: Wiss, Janney, Elstner Associates, Inc. 
Damage to inventory on industrial storage racks 
Earthquake Damage: 1994, Northridge, California 
Photo Credit: Wiss, Janney, Elstner Associates, Inc. 
Figure 4 Examples of Property Loss Due to Nonstructural Damage 
Broken sprinkler pipe at Olive View Hospital in Sylmar-pipe ruptured at the elbow joint due to 
differential motion within the ceiling plenum. Water leakage from broken fire sprinklers and water lines 
forced the hospital to close for several days. 
Earthquake Damage: 1994, Northridge, California 
Photo Credit: Robert Reitherman 
HVAC damage at Holy Cross Medical Center in Sylmar-damage to signage and louvers caused when suspended fans in the mechanical penthouse swung and impacted the louver panels. HVAC service 
outage caused the temporary evacuation of all patients. 
Earthquake Damage: 1994, Northridge, California 
Photo Credit: Robert Reitherman 
Figure 5 -Examples of Loss of Function Due to Nonstructural Damage 
in some cases water was flowing for many 
hours. At one facility, water up to 2 feet deep 
was reported at some locations in the building 
as a result of damage to the domestic water 
supply tank on the roof. At another, the 
emergency generator was disabled when its 
cooling water line broke where it crossed a 
separation joint. Other damage at these 
facilities included broken glass, dangling light 
fixtures, elevator counterweight damage, and 
lack of emergency power due to failures in the 
distribution or control systems. Two of these 
facilities, Los Angeles County Olive View 
Medical Center and Holy Cross Medical Center, 
both in Sylmar, California, had suffered severe 
structural damage or collapse during the 1971 
San Fernando earthquake and had been 
demolished and entirely rebuilt [3]. (See Figure 
5). 
* Of 32 data processing facilities surveyed 
following the 1989 Loma Prieta earthquake, at 
least 13 were temporarily out of operation for 
periods ranging from 4 to 56 hours. The 
primary cause of outage was loss of outside 
power; at least 3 facilities with Uninterruptible 
Power Supplies (UPS) or Emergency Power 
Systems (EPS) did not suffer any downtime. 
Reported damage included overturning of 
equipment (2 facilities); damage to access floors 
(4 facilities); movement of large pieces of 
computer equipment over distances ranging 
from a few inches to 4 feet (26 facilities); and 
dislodged ceiling panels (13 facilities). Twenty 
of these facilities reported having an earthquake 
preparedness program in place at the time of the 
earthquake, 3 reported no program, and 
information was unavailable for 9 facilities [2]. 
* The 1971 San Fernando earthquake caused 
extensive damage to elevators in the Los 
Angeles area, even in some structures where no 
other damage was reported. An elevator survey 
indicated 674 instances where counterweights 
came out of the guide rails, in addition to 
reports of other types of elevator damage. 
These elevators were inoperable until they could 
be inspected and repaired. Many thousands of 
businesses were temporarily affected by these 
elevator outages. The State of California 
instituted seismic elevator code provisions in 
1975, and while these provisions appear to have 
helped reduce the damage, there were still many 
instances of counterweight damage in the San 
Francisco area following the 1989 Loma Prieta 
earthquake [2], and 688 cases in the Northridge 
earthquake [3]. 
In some cases, cleanup costs or the value of lost 
employee labor are not the key measures of the 
postearthquake impact of an earthquake. For 
example, data processing facilities or financial 
institutions must remain operational on a 
minute-by-minute basis to maintain essential 
services and monitor transactions at distant 
locations. In such cases, spilled files or damage 
to communications and computer equipment 
may represent less tangible but more significant 
outage costs. Hospitals and fire and police 
stations are all facilities with essential functions 
that must remain operational after an 
earthquake; damage to their nonstructural 
elements can be a major cause of loss of 
functionality. 
CAUSES OF 
NONSTRUCTURAL DAMAGE 
Earthquake ground shaking has three primary 
effects on nonstructural elements in buildings. 
These are inertial or shaking effects on the 
nonstructural elements themselves, distortions 
imposed on nonstructural components when the 
building structure sways back and forth, and 
separation or pounding at the interface between 
adjacent structures (Figure 6). 
Inertial Forces When a building is shaken 
during an earthquake, the base of the building 
moves in unison with the ground, but the entire 
building and building contents above the base 
will experience inertial forces. These inertial 
forces can be explained by using the analogy of 
a passenger in a moving vehicle. As a 
passenger, you experience inertial forces 
whenever the vehicle is rapidly accelerating or 
decelerating. If the vehicle is accelerating, you 
may feel yourself pushed backward against the 
seat, since the inertial force on your body acts 
in the direction opposite that of the acceleration. 
If the vehicle is decelerating or braking, you 
may be thrown forward in your seat. Although 
the engineering aspects of earthquake inertial 
forces are more complex than a single principle 
of physics, the law first formulated by Sir Isaac 
Newton, F = ma, or force is equal to the mass 
times the acceleration, is the basic principle 
involved. In general, the earthquake inertial 
forces are greater if the mass is greater (if the 
building or object within the building weighs 
more) or if the acceleration or severity of the 
shaking is greater. 
File cabinets, emergency power-generating 
equipment, freestanding bookshelves, office 
equipment, and items stored on shelves or racks 
can all be damaged because of inertial forces. 
When unrestrained items are shaken by an 
earthquake, inertial forces may cause them to 
slide, swing, strike other objects, or overturn. 
Items may slide off shelves and fall to the floor. 
One common misconception is that large, heavy 
objects are stable and not as vulnerable to 
earthquake damage as lighter objects, perhaps 
because we may have difficulty moving them. 
In fact, many types of objects may be 
vulnerable to earthquake damage caused by 
inertial forces: since inertial forces during an 
earthquake are proportional to the mass or 
weight of an object, a -heavily loaded file 
cabinet requires much stronger restraints to keep 
it from sliding or overturning than a light one 
with the same dimensions. 
Building Distortion During an earthquake, 
building structures distort, or bend, from side to 
side in response to the earthquake forces. For 
example, the top of a tall office tower may lean 
over a few feet in each direction during an 
earthquake. The distortion over the height of 
each story, known as the story drift, might 
range from 14inch to several inches, depending 
on the size of the earthquake and the 
characteristics of the particular building 
structure. Windows, partitions, and other items 
that are tightly locked into the structure are 
forced to go along for the ride. As the columns 
or walls distort and become slightly out of 
square, if only for an instant, any tightly 
confined windows or partitions must also distort 
the same amount. The more space there is 
around a pane of glass where it is mounted 
between stops or molding strips, the more 
distortion the glazing assembly can 
accommodate before the glass itself is subjected 
to earthquake forces. Brittle materials like 
glass, plaster or drywall partitions, and masonry 
infill or veneer cannot tolerate any significant 
distortion and will crack when the perimeter 
gaps close and the building structure pushes 
directly on the brittle elements. Most 
architectural components such as glass panes, 
partitions, and veneer are damaged because of 
this type of building distortion, not because they 
themselves are shaken or damaged by inertial 
forces. 
There have also been notable cases of structural nonstructural 
interaction in past earthquakes, 
where rigid nonstructural components have been 
the cause of structural damage or collapse. 
These cases have generally involved rigid, 
strong architectural components, such as 
masonry infill or concrete spandrels, that inhibit 
the movement or distortion of the structural 
framing and cause premature failure of column 
or beam elements. While this is -a serious 
concern for structural designers, the focus of 
this guide is on earthquake damage to 
nonstructural components. 
Building Separations Another source of 
nonstructural damage involves pounding or 
movement across separation joints between 
OVERTURNING OF 
SLENDER OBJECTS 
SLIDING OF 
STOCKY OBJECTS 
UPLIFT 
SLIDING ANDO
OERTRNING 
BREAKAGE OF
GLASS OR
PARTITIONS 
IMPOSED DEFORMATION
DEFORMED SHAPE BREAKAGE OF PIPING OR DUCTS MAY OCCUR AT 
OF BUILDING SEISMIC JOINTS DUE TO DIFFERENTIAL 
DISPLACEMENTS (SEPARATION AND POUNDING) 
DEFORMED SHAPE 
OF BUILDING 
BUILDING SEPARATION 
Figure 6 -Effects of Earthquakes on Nonstructural Components
adjacent structures. A separation joint, is the 
distance between two different building 
structures, often two wings of the same facility, 
that allows the structures to move independently 
of one another. A seismic gap is a separation 
joint provided to accommodate relative lateral 
movement during an earthquake. In order to 
provide functional continuity between separate 
wings, building utilities must often extend 
across these building separations, and 
architectural finishes must be detailed to 
terminate on either side. For base-isolated 
buildings that are mounted on seismic shock 
absorbers, a seismic isolation gap occurs at the 
ground level, between the foundation and the 
base of the superstructure. The separation joint 
may be only an inch or two in older 
construction or as much as a foot in some newer 
buildings, depending on the expected horizontal 
movement, or seismic drift. Flashing, piping, 
fire sprinkler lines, HVAC ducts, partitions, and 
flooring all have to be detailed to accommodate 
the seismic movement expected at these 
locations when the two structures move closer 
together or further apart. Damage to items 
crossing seismic gaps is a common type of 
earthquake damage. If the size of the gap is 
insufficient, pounding between adjacent 
structures may result in damage to structural 
components but often causes damage to 
nonstructural components, such as parapets, 
veneer, or cornices on the facades of older 
buildings. 
METHODS FOR REDUCING 
NONSTRUCTURAL HAZARDS 
There are a variety of methods available to 
reduce the potential risks associated with 
earthquake damage to nonstructural components. 
These methods range from simple commonsense 
steps one can take oneself to complex solutions 
requiring professional help. Simple steps might 
include relocating top-heavy furniture away 
from the doorway or bed in a bedroom and 
installing some of the simple do-it-yourself 
anchorage details presented in this guide. Large 
organizations with complex facilities may need 
to hire professional consultants to design 
engineering details for building utilities and 
architectural components. For facilities such as 
hospitals, museums, libraries, research 
laboratories, and industrial facilities, 
professional consultants would probably be 
needed to provide specific design details for 
specialized building contents as well. 
Facility Survey Nonstructural hazards may 
be present in any type of facility-a home, an 
office, a church, a day care center, a retail 
store, a nursing care facility, a school, a light 
manufacturing plant. Chapter 3 includes 
guidelines for performing a facility survey to 
identify potential nonstructural hazards. The 
forms and checklists provided in this guide are 
intended for use by laypersons, i.e., 
nonengineers, who are familiar with the building 
or facility to be surveyed. The process of 
conducting the survey should help to increase 
user awareness of the potential problems. The 
results of the survey should help building 
owners, managers, and/or occupants understand 
the scope of the potential problems and assess 
the building's seismic vulnerability, or present 
level of risk of nonstructural earthquake 
damage. 
Commonsense Measures A facility 
survey may identify many items that represent 
a high or moderate risk in their present location 
but that could readily be relocated to reduce the 
potential risk. The answers to the following 
questions may help identify commonsense 
measures that can be used to reduce many of the 
potential risks. 
* Where do you, your family, and your 
employees spend the most time? Are there 
heavy, unstable items near your desk or bed that 
could be moved? What is the probability that 
someone will be injured by various items if they 
fall? Which areas of the building have a higher 
occupant load and hence a potentially higher life 
safety risk? Are there items that no longer 
serve a useful function and can be removed? 
What items can be relocated to prevent possible 
injury and do not need to be anchored to 
prevent damage or loss? 
* If something slides or falls, in what direction 
is it likely to go? While the answer to this 
question is not always obvious, it may be useful 
to rearrange some furniture and move tall or 
heavy objects to where they cannot block a door 
or an exit. Shelved items might be rearranged 
so that heavier items are near the bottom and 
lighter ones near the top. Incompatible 
chemicals can be moved to prevent mixing if the 
containers break. Excess supplies or inventory 
could be stored in the original shipping 
containers until ready for use, in order to reduce 
the possibility of breakage. 
Upgrade Details There are many 
techniques available to reduce potential 
nonstructural earthquake damage. Possible 
upgrade schemes might include one or more of 
the following measures: use anchor bolts to 
provide rigid anchorage to a structural floor or 
wall; brace the item to a structural wall or 
floor; provide a tether or safety cable to limit 
the range of movement if the item falls or 
swings; provide stops or bumpers to limit the 
range of movement if the item slides; provide 
flexible connections for piping and conduit 
where they cross seismic joints or connect to 
rigidly mounted equipment; attach contents to a 
shelf, desktop, or countertop; provide base 
isolation or seismic shock absorbers for 
individual pieces of vital equipment. 
Some of these methods are designed to protect 
the functional integrity of a particular item, 
some are designed merely to reduce the 
consequences of failure. It is important to 
understand the applicability and limitations of 
the various upgrade schemes and to select an 
appropriate scheme for a particular item in a 
particular context. 
Critical and expensive items warrant specialized 
attention. For essential facilities in areas where 
severe shaking is anticipated, any or all of the 
following elements may be needed in order to 
provide an appropriate level of nonstructural 
protection: specialized engineering expertise, 
higher design forces than those required by the 
code, experienced specialty contractors, special 
construction inspection, load-rated hardware, 
vendor-supplied equipment that has been tested 
on a shaking table, special design details such as 
base isolation for individual pieces of 
equipment, larger seismic gaps to prevent 
pounding between adjacent structures, or stiffer 
structural systems such as shear walls to avoid 
excessive distortion of the structural framing. 
Organizational Planning Programs In 
an organizational setting, an effective program 
to reduce nonstructural earthquake hazards may 
have to be integrated with other organizational 
functions, including earthquake preparedness, 
emergency response, facilities maintenance, 
procurement, long-term planning, and/or 
facilities development. Some organizations 
might choose to embark on an ambitious 
program to anchor all of their existing 
equipment and contents, while others may 
concentrate on new facilities and new 
equipment. Many different implementation 
strategies are possible. Programs to develop 
employee awareness and provide emergency 
training might be in order for some 
organizations, since a successful nonstructural 
hazards reduction program has to address the 
many human factors issues along with the 
engineering issues. 
BUILDING CODE 
REQUIREMENTS FOR 
NONSTRUCTURAL 
COMPONENTS 
By and large, advances in earthquake 
engineering made in recent decades have been 
successfully applied to the task of making 
building structures safer. In comparison, there 
has been much less application of this technical 
knowledge to the nonstructural components of 
buildings, although this is gradually changing. 
Design professionals, code committees, and 
building owners are learning that the seismic 
resistance of critical nonstructural components 
must be addressed as part of the design process, 
since failures of nonstructural components may 
threaten the safety of building occupants and 
result in significant financial loss. 
Code Philosophy Surveys of existing 
buildings indicate that many nonstructural items 
are never explicitly designed to resist horizontal 
forces. Instead, they are installed in accordance 
with common construction practice, which 
varies little from seismic to nonseismic areas. 
Modern building codes typically include some 
seismic provisions, that apply to a limited list of 
nonstructural items. Many nonstructural items 
are not specifically addressed in the provisions 
and may therefore be interpreted as being 
exempt from code requirements. For example, 
some specific code provisions, apply to concrete 
masonry unit fences taller than 6 feet, but a 5 
foot tall masonry wall without proper 
reinforcing can also be a hazard. 
The fact that the building code is not as specific 
about nonstructural items as it is about the 
structural portions of buildings is indicative of 
the general intent of the earthquake provisions 
to provide a minimum level of life safety and to 
avoid legislating property damage control 
measures. In general, the concepts of life safety 
and prevention of structural collapse have been 
used almost interchangeably in the thinking 
underlying the earthquake regulations in the 
building code, although it is apparent that there 
are significant nonstructural dangers to life and 
limb as well. In some cases, the potential for 
nonstructural property loss or outage is a strong 
reason for obtaining more than the code 
minimum level of protection. Indeed, even 
code requirements in early 1994 for the design 
of nonstructural items in medical facilities in 
California, which were more stringent than 
those for office and residential occupancies, 
were apparently not restrictive enough to 
completely prevent disruption of service 
following the January 1994 Northridge 
earthquake. 
The point of this discussion is to emphasize the 
life safety focus of current building code 
provisions, which are intended primarily to 
reduce potential injuries, not to prevent costly 
damage or loss of function. Code provisions, 
for nonstructural components are subject to 
revision every three years, and in the future 
these provisions may be revised to aim for a 
higher level of nonstructural protection. 
Engineering Design To design protective 
devices such as bolted connections, snubbers, or 
restraining cables, engineers use a percentage of 
the weight of the object as the horizontal 
earthquake force that must be resisted by the 
design details. Design guidelines developed by 
the National Earthquake Hazards Reduction 
Program (NEIHRP) are contained in NEHRP 
Recommended Provisions for the Development of 
Seismic Regulations for New Buildings [9]. 
Many state and local codes have adopted similar 
design provisions for nonstructural components. 
These provisions specifically address earthquake 
inertial forces. The engineer must also account 
for the effects of building distortion (i.e., 
seismic relative displacements between two 
connection points in the same building or 
structural system) and the effects of building 
separations (i.e., seismic relative displacements 
between two connection points on separate 
buildings or structural systems) in the design. 
The following is a brief description of the 
simplest type of engineering design procedure. 
Minimum design levels for architectural, 
mechanical, and electrical systems and 
components are described in the NEHRP 
provisions. The provisions specify horizontal 
seismic force factors to be used for the design 
of specific items, such as partitions, parapets, 
chimneys, ornaments, tank supports, storage 
racks over 8 feet tall, equipment or machinery, 
piping, and suspended ceilings. According to 
the NEHRP procedure, the design force depends 
on a variety of factors such as, the seismic 
zone, the type of component, the location of the 
item within a building, and the type of 
occupancy. Design forces are generally greater 
for emergency generators than for HVAC 
equipment, greater for police and fire stations 
than for ordinary office buildings, and greater at 
the roof than at the ground. 
To use a specific case, the specified horizontal 
force for a piece of rigid equipment situated at 
ground level in a commercial facility in the Los 
Angeles area is 40% of the weight of the item. 
If the equipment weighs 1000 pounds, the 
engineer must design the bracing and floor or 
wall anchorage details to resist 400 pounds of 
horizontal force acting through the center of 
gravity of the item in any direction. If the item 
is used to store hazardous contents or is located 
on a floor above ground level, the NEHRP 
provisions require higher design forces. Under 
some circumstances, an owner who is 
particularly concerned about postearthquake 
operations may want a greater level of 
protection than is provided by the minimum 
requirements in the NEHRP provisions. In this 
case, the owner and engineer or equipment 
vendor should discuss the performance criteria 
at the beginning of the project, as described in 
Chapter 7. 
This discussion of seismic forces is intended to 
illustrate the design procedure and the 
magnitude of the loads, not to turn the 
layperson into an engineer. This guide does not 
advocate the use by nonengineers of the 
calculation procedure described above. 
SEISMIC HAZARD 
The seismic risk for a particular nonstructural 
component at a particular facility is governed by 
a variety of factors, including the regional 
seismicity, the proximity to an active fault, the 
local soil conditions, the dynamic characteristics 
of the building structure, the dynamic 
characteristics of the nonstructural component 
and any connections to the structure, the 
location of the nonstructural component within 
the building, the function of the facility, and the 
importance of the particular component to the 
operation of the facility. While all of these 
factors may have to be considered in the 
evaluation of equipment in a hospital or nuclear 
facility, we will consider only the issue of 
regional seismicity for the purposes of this 
discussion. 
The seismic hazard in a given region or 
geographic location is related both to the 
severity of ground shaking expected in the area 
and to the likelihood, or probability, that a 
given level of shaking will occur. Seismologists 
review historical earthquake activity, locations 
and characteristics of mapped faults, and 
regional geology to estimate the seismic hazard. 
This information is often depicted on a seismic 
hazard map. 
For the purposes of this guide, seismic hazard 
has been characterized in terms of three levels 
of shaking intensity: namely light, moderate, 
and severe. The seismic hazard maps presented 
in Figure 7 show the geographic areas in the 
United States where light, moderate and severe 
shaking are likely to occur in future 
earthquakes. 
For engineering purposes, earthquake shaking is 
often characterized by an effective peak 
acceleration (EPA), measured as a percentage of 
the acceleration of gravity. The effective peak 
18