seismic bracing of today’s speakers and topics...

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Presented byPresented byStructural Engineers Association of UtahStructural Engineers Association of Utah

Seismic CommitteeSeismic Committee

SEISMIC BRACING OF NON-STRUCTURAL ELEMENTS

TodayToday’’s Speakers and Topicss Speakers and Topics

• 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

Topics To Begin WithTopics To Begin WithJohn Masek, SEJohn Masek, SE

– Why is Non-Structural Seismic Bracing Important?

– What is the Current State of Practice?

WhyWhy is Nonis Non--Structural Seismic Bracing Structural Seismic Bracing Important?Important?

• 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


SLC is undoubtedly at risk of a seismic event


Do those in the industry think that nonstructural bracing is occurring correctly now?....not really!!

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• 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


• Lack of attention for details (i.e. reliance on “typical” details) can lead to unacceptable damage to critical faculties


• Even Small Earthquakes can cause significant nonstructural damage if designs are not done correctly (M5.9 Whittier EQ damage shown)

What is the What is the CurrentCurrent State of Practice?State of Practice?THE EARTHQUAKE ENGINEERING RESEARCH INSTITUTETHE EARTHQUAKE ENGINEERING RESEARCH INSTITUTE

SPECIAL PROJECTS AND INITIATIESSPECIAL PROJECTS AND INITIATIES

Identification of Methods to Achieve Successful Implementation of Nonstructural and Equipment Seismic Restraints

John Masek, S.E.,VIE ConsultantsMember EERI, Robert Ridge, PhDBrigham Young University

WhatWhat is the Current State of Practice?is the Current State of Practice?

- The purpose of this research was to identify methods to cause proper designand 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?

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WhatWhat is the Current State of Practice?is the Current State of Practice?

The procedure that was used:1) Interviews of a selected group of peers to identify

potential key issues2) Development of an internet based survey using

“Qualtrics” Software3) Collection and Analysis of Survey Results over a nine

month period of time, along with telephone interviews4) Data gathered from 300 plus people in California, Utah

and Washington State5) Twelve target respondent groups initially, this was

expanded.6) Analysis of data and development of

recommendations

Who responded to the survey:Who responded to the survey:

What What is the Current State of Practice?is the Current State of Practice?

• Where survey respondents practiced:

Who did respondents think was Who did respondents think was ultimatelyultimatelyresponsible for nonstructural seismic bracing?responsible for nonstructural seismic bracing?

Why did respondents think noncompliance with Why did respondents think noncompliance with nonstructural earthquake standards occurs?nonstructural earthquake standards occurs?

How did respondents think compliance with nonstructural How did respondents think compliance with nonstructural seismic design provisions could be improved?seismic design provisions could be improved?

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How did respondents think compliance with nonstructural How did respondents think compliance with nonstructural seismic design provisions could be improved?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 equationThe next part of the equation The Next Part: CodesThe Next Part: CodesDon Barker, SEDon Barker, SE

– What Must Be Braced – Typical Construction Details

Seismic Bracing of NonSeismic Bracing of Non--Structural Structural ComponentsComponents

References

• 2006 International Building Code (IBC)

“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”

• ASCE/SEI 7-05 Minimum Design Loads for Buildings and Other Structures

• FEMA 450-2/2003 NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other Structures

• FEMA 412/December 2002 Installing Seismic Restraints for Mechanical Unitshttp://www.fema.gov/plan/prevent/earthquake/professionals.shtm

• FEMA 413/January 2004 Installing Seismic Restraints for Electrical Equipment

• FEMA 414/January 2004 Installing Seismic Restraints for Ducts and Pipes

• ASCE 41-06 Seismic Rehabilitation of Existing Structures

ASCE/SEI 7ASCE/SEI 7--05 Chapter 13 05 Chapter 13 ““Seismic Design for NonSeismic Design for Non--Structural Structural

ComponentsComponents””What Are Non-Structural Components?

• Architectural Components (ASCE 7-05 Section 13.5, Table13.6-1)

• Mechanical Components (ASCE 7-05 Section 13.6 , Table13.6-1)

• Electrical Components (ASCE 7-05 Section 13.6 , Table13.6-1)

• Vibration Isolated Components and Systems (ASCE 7-05 Table 13.6-1)

• Distribution Systems (ASCE 7-05 Table 13.6-1)

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Architectural ComponentsArchitectural Components

• 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

Typical Suspended Ceiling DetailTypical Suspended Ceiling Detail

Standard Architectural Detail Found in Architectural Plans

Typical Bracing for Nonstructural Typical Bracing for Nonstructural Masonry WallMasonry Wall

BHB Engineering Standard Bracing Detail

Mechanical ComponentsMechanical 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

Examples of Mechanical Examples of Mechanical Equipment AnchorageEquipment Anchorage

• Reference: FEMA 412 “Installing Seismic Restraint For • Mechanical Equipment”

Examples of Mechanical Examples of Mechanical Equipment AnchorageEquipment Anchorage


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Electrical ComponentsElectrical 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

Examples of Electrical Component Examples of Electrical Component AnchorageAnchorage

• Reference: FEMA 413 “Installing Seismic Restraint For • Electrical Equipment”

Example of Electrical Component Example of Electrical Component AnchorageAnchorage

• Reference: FEMA 413 “Installing Seismic Restraint For • Electrical Equipment”

Vibration Isolated Components and Vibration Isolated Components and SystemsSystems

• 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

Example of Vibration Isolated Example of Vibration Isolated Equipment AnchorageEquipment Anchorage


Distribution SystemsDistribution Systems

• Piping in Accordance with ASME B31• Piping and Tubing not in Accordance with ASTM

B31• Piping and Tubing Constructed of Low-

Deformability 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 Example of Distribution System AnchorageAnchorage


ASCE/SEI 7ASCE/SEI 7--05 Section 13.405 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 designedand constructed for the component forces where they control the design of the elements or their connections.”

“The design documents shall include sufficient information relating to the attachments to verify compliance with the requirements of this section.”

Topics To End WithTopics To End WithStephen Cohen, SEStephen Cohen, SE

– Who is Responsible?– What Code Documentation is required?– What to look for in the field?

WhoWho’’s Responsible?s Responsible?

• Owner?• Architect?• Structural Engineer?• Mechanical Engineer?• Electrical Engineer?• Contractor?• Building Official/Inspector?• Special Inspector?

Who did respondents think was Who did respondents think was ultimatelyultimatelyresponsible for nonstructural seismic bracing?responsible for nonstructural seismic bracing?

ASCE 13.2.7 Construction ASCE 13.2.7 Construction Documents.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 professionalin responsible charge

• For use by the owner, building officials, contractors, and inspectors

• Documents shall include a quality assuranceplan per IBC 1707.7 and 1707.8

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ASCE Table ASCE Table --13.213.2--11 ASCE 13.1.3 Component ASCE 13.1.3 Component Importance FactorImportance Factor

Ip > 1.0 if any of the following conditions apply:

1. The component is required to function for life-safety 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 IVOccupancy Category IV

Essential Facilities per IBC Table 1604.5Includes:• 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 IBC 1708.5 Seismic Qualification of Mechanical and Electrical EquipmentMechanical 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 IBC 1708.5 Seismic Qualification of Mechanical and Electrical EquipmentMechanical and Electrical EquipmentContinued• 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 Special Inspection RequirementsRequirements

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IBC 1707.7 Architectural IBC 1707.7 Architectural ComponentsComponents

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 wallsweighing 15 psf (73.5 N/m2) or less.

IBC 1707.8 Mechanical and IBC 1707.8 Mechanical and Electrical ComponentsElectrical 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

IBC 1707.8 Mechanical and IBC 1707.8 Mechanical and Electrical ComponentsElectrical Components

Continued3. 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.

Seismic Design CategorySeismic Design CategoryTABLE 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 AsField As--Built PhotosBuilt Photos

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Questions??Questions??