Today’
Today’s Speakers and Topics
SEISMIC BRACING OF
NON-STRUCTURAL ELEMENTS
Presented by
Structural Engineers Association of Utah
Seismic Committee
• John Masek, SE
– Why is Non-Structural Seismic Bracing Important
– What is the Current State of Practice
• Don Barker, SE
– What Must Be Braced
– Typical Construction Details (Do They Work?)
• Stephen Cohen, SE
– Who Is Responsible???
– What Code Documentation is required?
– What To Look For In The Field
Why is NonNon-Structural Seismic Bracing
Important?
Topics To Begin With
John Masek, SE
– Why is Non-Structural Seismic Bracing
Important?
– What is the Current State of Practice?
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Why is NonNon-Structural Seismic Bracing
Important?
SLC is undoubtedly at risk
of a seismic event
For essential facilities avoiding
nonstructural and equipment
items may be more important to
the owner than sustaining
moderate but repairable
structural damage
Nonstructural damage has
historically accounted for 25% to
50% of the damage observed in
recent United States
Earthquakes
Even for more common small to
moderate earthquakes,
nonstructural damage may
represent a life safety hazard if
not addressed in design
Why is NonNon-Structural Seismic Bracing
Important?
Do those in the industry think that nonstructural
bracing is occurring correctly now?....not really!!
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Why is NonNon-Structural Seismic Bracing
Important?
• In some facilities,
nonstructural items are of
higher value and more
important than the
structure, i.e. some
structural damage may
occur, but equipment
must remain functional
• Retrofit after initial
installation can be more
difficult than if work is
done correctly in the first
place
• “It’s so heavy it can’t
move” doesn’t work.
F=MA
Why is NonNon-Structural Seismic Bracing
Important?
• Lack of attention for
details (i.e. reliance
on “typical” details)
can lead to
unacceptable damage
to critical faculties
What is the Current State of Practice?
THE EARTHQUAKE ENGINEERING RESEARCH INSTITUTE
SPECIAL PROJECTS AND INITIATIES
Identification of
Methods to Achieve
Successful
Implementation of
Nonstructural and
Equipment Seismic
Restraints
Why is NonNon-Structural Seismic Bracing
Important?
Why is NonNon-Structural Seismic Bracing
Important?
• Even Small
Earthquakes can
cause significant
nonstructural damage
if designs are not
done correctly (M5.9
Whittier EQ damage
shown)
What is the Current State of Practice?
- The purpose of this research was to
identify methods to cause proper design
and construction of nonstructural and
equipment seismic restraints to occur as a
matter of standard practice.
- Why not ask those who are in the industry
from owners to designers to construction
firms and building officials?
John Masek, S.E.,
VIE Consultants
Member EERI,
Robert Ridge, PhD
Brigham Young University
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What is the Current State of Practice?
Who responded to the survey:
The procedure that was used:
1)
2)
3)
4)
5)
6)
Interviews of a selected group of peers to identify
potential key issues
Development of an internet based survey using
“Qualtrics” Software
Collection and Analysis of Survey Results over a nine
month period of time, along with telephone interviews
Data gathered from 300 plus people in California, Utah
and Washington State
Twelve target respondent groups initially, this was
expanded.
Analysis of data and development of
recommendations
What is the Current State of Practice?
Who did respondents think was ultimately
responsible for nonstructural seismic bracing?
• Where survey respondents practiced:
Why did respondents think noncompliance with
nonstructural earthquake standards occurs?
How did respondents think compliance with nonstructural
seismic design provisions could be improved?
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Why is NonNon-Structural Seismic Bracing
Important?
How did respondents think compliance with nonstructural
seismic design provisions could be improved?
Bottom line:
Do YOU want to explain to
your client or employer,
or municipality why their
facility was extensively
damaged because it was
“not your job” to make
sure nonstructural issues
were correctly
addressed?
The next part of the equation
The Next Part: Codes
Don Barker, SE
– What Must Be Braced
– Typical Construction Details
ASCE/SEI 77-05 Chapter 13
“Seismic Design for NonNon-Structural
Components”
Components”
Seismic Bracing of NonNon-Structural
Components
References
•
2006 International Building Code (IBC)
What Are Non-Structural Components?
“Every structure, and portion thereof, including nonstructural components that are permanently
attached to structures and their supports and attachments, shall be designed and constructed to
resist the effects of earthquake motion in accordance with ASCE7”
•
Architectural Components (ASCE 7-05 Section 13.5, Table13.6-1)
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ASCE/SEI 7-05 Minimum Design Loads for Buildings and Other Structures
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Mechanical Components (ASCE 7-05 Section 13.6 , Table13.6-1)
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FEMA 450-2/2003 NEHRP Recommended Provisions for Seismic Regulations for New Buildings
and Other Structures
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Electrical Components (ASCE 7-05 Section 13.6 , Table13.6-1)
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FEMA 412/December 2002 Installing Seismic Restraints for Mechanical Units
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Vibration Isolated Components and Systems (ASCE 7-05 Table 13.6-1)
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Distribution Systems (ASCE 7-05 Table 13.6-1)
http://www.fema.gov/plan/prevent/earthquake/professionals.shtm
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FEMA 413/January 2004 Installing Seismic Restraints for Electrical Equipment
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FEMA 414/January 2004 Installing Seismic Restraints for Ducts and Pipes
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ASCE 41-06 Seismic Rehabilitation of Existing Structures
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Architectural Components
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Typical Suspended Ceiling Detail
Interior Nonstructural Walls and Partitions
Cantilevered Elements (parapets and chimneys, cantilevered interior
nonstructural walls).
Cantilevered Elements (parapets, chimneys, exterior nonstructural walls)
Veneer
Penthouses
Suspended Ceilings
Cabinets
Access Floors
Appendages and Ornamentations
Signs and Billboards
Glass
Partitions
Glass in Glazed Curtain Walls, Glazed Storefronts, and Glazed Partitions
Standard Architectural Detail Found in Architectural Plans
Typical Bracing for Nonstructural
Masonry Wall
Mechanical Components
• Air-Side HVAC, Fans, Air Handlers, Air
Conditioning Units, Cabinet Heaters, Air
Distribution Boxes, etc.
• Wet-Side HVAC, Boilers, Furnaces, Atmospheric
Tanks and Bins, Chillers, Water Heaters, Heat
Exchangers, Evaporators, Air Separators,
Manufacturing or Process Equipment, etc.
• Engines, Turbines, Pumps, Compressors, and
Pressure Vessels Not Supported on Skirts.
• Elevator and Escalator Components
BHB Engineering Standard Bracing Detail
Examples of Mechanical
Equipment Anchorage
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Reference: FEMA 412 “Installing Seismic Restraint For
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Mechanical Equipment”
Examples of Mechanical
Equipment Anchorage
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Reference: FEMA 412 “Installing Seismic Restraint For
•
Mechanical Equipment”
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Electrical Components
• Generators, Batteries, Inverters, Motors,
Transformers, etc.
• Motor Control Centers, Panel Boards, Switch
Gear, Instrumentation Cabinets
• Communication Equipment, Computers,
Instrumentation, and Controls
• Roof-Mounted Chimneys, Stacks, Cooling and
Electrical Towers, Laterally Braced Above or
Below Their Centers of Mass
• Lighting Fixtures
• Other Electrical Components
Example of Electrical Component
Anchorage
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Reference: FEMA 413 “Installing Seismic Restraint For
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Electrical Equipment”
Example of Vibration Isolated
Equipment Anchorage
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Reference: FEMA 412 “Installing Seismic Restraint For
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Mechanical Equipment”
Examples of Electrical Component
Anchorage
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Reference: FEMA 413 “Installing Seismic Restraint For
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Electrical Equipment”
Vibration Isolated Components and
Systems
• Components and Systems Isolated Using
Neoprene Elements
• Spring Isolated Components and Systems
• Internally Isolated Components and
Systems
• Suspended Vibration Isolated Equipment
Including In-Line Duct Devices and
Suspended Internally Isolated
Components
Distribution Systems
• Piping in Accordance with ASME B31
• Piping and Tubing not in Accordance with ASTM
B31
• Piping and Tubing Constructed of LowDeformability Materials
• Ductwork including in-line Components
• Electrical Conduit, Bas Ducts, Rigidly Mounted
Cable Trays, and Plumbing
• Manufacturing or Process Conveyors
• Suspended Cable Trays
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Example of Distribution System
Anchorage
ASCE/SEI 77-05 Section 13.4
Section 13.4 Nonstructural Component Anchorage
“Component attachments shall be bolted, welded, or otherwise
positively fastened without consideration of frictional resistance
produced by the effects of gravity”
“A continuous load path of sufficient strength and stiffness between
the component and the supporting structure shall be provided. Local
elements of the structure including connection shall be designed
and constructed for the component forces where they control the
design of the elements or their connections.”
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“The design documents shall include sufficient information relating
to the attachments to verify compliance with the requirements of this
section.”
Reference: FEMA 412 “Installing Seismic Restraint For
•
Mechanical Equipment”
Who’
Who’s Responsible?
Topics To End With
Stephen Cohen, SE
– Who is Responsible?
– What Code Documentation is required?
– What to look for in the field?
Who did respondents think was ultimately
responsible for nonstructural seismic bracing?
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Owner?
Architect?
Structural Engineer?
Mechanical Engineer?
Electrical Engineer?
Contractor?
Building Official/Inspector?
Special Inspector?
ASCE 13.2.7 Construction
Documents.
When required by Table 13.2-1 non-structural
components, their supports and their
attachments:
• Shall be shown in construction documents
prepared by the registered design professional
in responsible charge
• For use by the owner, building officials,
contractors, and inspectors
• Documents shall include a quality assurance
plan per IBC 1707.7 and 1707.8
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ASCE Table -13.213.2-1
ASCE 13.1.3 Component
Importance Factor
Ip > 1.0 if any of the following conditions apply:
1. The component is required to function for lifesafety purposes after an earthquake, including
fire protection sprinkler systems.
2. The component contains hazardous materials.
3. The component is in or attached to an
Occupancy Category IV structure and it is
needed for continued operation of the facility
Occupancy Category IV
Essential Facilities per IBC Table 1604.5
Includes:
• Hospitals with surgery and other emergency
treatment facilities
• Fire, Rescue and Police Stations and Garages
• Emergency Shelters
• Emergency Communications Centers
• Utilities required for emergency power and fire
suppression, etc.
IBC 1708.5 Seismic Qualification of
Mechanical and Electrical Equipment
• Registered design professional in responsible
charge shall state the applicable seismic
qualification requirements on the construction
documents
• Each manufacturer of designated components
shall test or analyze the component and its
mounting system and anchorage
Continued Next Slide
IBC 1708.5 Seismic Qualification of
Mechanical and Electrical Equipment
Continued
• Shall submit a certificate of compliance for
review and acceptance by the registered design
professional in responsible charge and for
approval by the building official.
• Qualification shall be by:
– an actual test on a shake table
– use of experience data
– rigorous analysis providing for equivalent
safety
Special Inspection
Requirements
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IBC 1707.7 Architectural
Components
Periodic special inspection is required during the erection and
fastening of exterior cladding, interior and exterior nonbearing walls
and interior and exterior veneer in structures assigned to Seismic
Design Category D, E or F.
Exceptions:
– 1. Special inspection is not required for exterior cladding, interior and
exterior nonbearing walls and interior and exterior veneer in structures
30 feet (9144 mm) or less in height.
– 2. Special inspection is not required for cladding and veneer weighing
5 psf (24.5 N/m2) or less.
– 3. Special inspection is not required for interior nonbearing walls
weighing 15 psf (73.5 N/m2) or less.
IBC 1707.8 Mechanical and
Electrical Components
Continued
3. Required during installation of piping systems
intended to carry flammable, combustible or highly toxic
contents and their associated mechanical units for
Seismic Design Category C, D, E or F;
4. Required for installation of HVAC ductwork that will
contain hazardous materials for Seismic Design
Category C, D, E or F; and
5. Required for installation of vibration isolation systems
Seismic Design Category C, D, E or F when a nominal
clearance of 0.25 inches or less between the equipment
support frame and restraint.
IBC 1707.8 Mechanical and
Electrical Components
Special inspection (periodic) for mechanical and
electrical equipment shall be as follows:
1. Required for anchorage of electrical equipment for
emergency or standby power systems for Seismic
Design Category C, D, E or F;
2. Required for anchorage of other electrical equipment
for Seismic Design Category E or F;
Continued Next Slide
Seismic Design Category
TABLE 1613.5.6(1) SEISMIC DESIGN CATEGORY
BASED ON SHORT-PERIOD RESPONSE
ACCELERATIONS
TABLE 1613.5.6(2) SEISMIC DESIGN CATEGORY
BASED ON 1-SECOND RESPONSE
ACCELERATIONS
When S1 is greater than or equal to 0.75 shall be assigned to
Seismic Design Category E. Structures classified as Occupancy
Category IV where S1 is greater than or equal to 0.75 shall be
assigned to Seismic Design Category F
Field As-Built Photos
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Questions??
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