1. International Seismic Application Technology
Engineered Seismic Bracing Systems
and Services
ASCE 7-10 SEISMIC DESIGN REQUIREMENTS
FOR MEP NON-STRUCTURAL COMPONENTS
For :
GAYNER ENGINEERS
Presented by Tim Lindfelt, Regional
Engineering Manager 1
2. Why Is Seismic Bracing Required for
MEP Systems
Life Safety Functionality
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3. EXAMPLE:
1994 NORTHRIDGE EARTHQUAKE
80-90% of the damage was to NON-structural elements
10 Essential Hospitals temporarily inoperable due
primarily to water damage, broken glass, dangling
light fixtures, and lack of emergency power due to
failures in the distribution or control systems.
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12. Ip =1.5 EXAMPLES
Examples of life-safety :
• Fire protection system
• Smoke exhaust system
• Power to life-safety/hazardous
systems
• Emergency Power
• Flammable, toxic, hazardous
Examples of Risk
Category IV Buildings :
• Acute Care Hospitals
• Emergency Response
Centers/Shelters
• Fire/Police Stations
• Air Traffic Control Towers
• Water Facilities Supplying OCC
CAT IV Buildings
• Some Buildings
Storing/Processing Hazardous
Materials
• Strategic National Defense
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13. SEISMIC DEMANDS ON
NONSTRUCTURAL COMPONENTS
13.3.1 – SEISMIC DESIGN FORCE
UPPER LIMIT
LOWER LIMIT
With Modal AnalysisWithout Modal Analysis
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14. SEISMIC DEMANDS ON
NONSTRUCTURAL COMPONENTS
FLOOR MOUNTED per TABLE 13.6-1
High Deformability Component
ap = 1.0 and Rp = 2.5 (ap/Rp = 0.4)
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15. SEISMIC DEMANDS ON
NONSTRUCTURAL COMPONENTS
FLOOR MOUNTED per TABLE 13.6-1
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Spring Isolated Component
ap = 2.5 and Rp = 2.0 (ap/Rp = 1.25)
16. SEISMIC DEMANDS ON
NONSTRUCTURAL COMPONENTS
DISTRIBUTED per TABLE 13.6-1
Pipes welded or brazed
ap = 2.5 and Rp = 12.0 (ap/Rp = 0.2)
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18. SEISMIC DEMANDS ON
NONSTRUCTURAL COMPONENTS
DISTRIBUTED
Low Deformable Material (Glass or Cast Iron
ap = 2.5, Rp = 3.0 ap/Rp = 0.83)
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GLASS PIPES CAST IRON PIPES
19. WHAT REQUIRES BRACING?
PER 13.1.4:
SUSPENDED/WALL MOUNTED COMPONENTS OVER 20LBS OR 5PLF
FLOOR MOUNTED EQUIPMENT OVER 400LBS OR CENTER OF GRAVITY 4 FT
OR HIGHER ABOVE FLOOR
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20. WHAT REQUIRES BRACING….
ELECTRICAL SYSTEMS (RACEWAYS):
SEISMIC DESIGN CAT. C,D,E,F:
Ip=1.5– Conduit > 2.5” dia. (SDC C)
Ip=1.0 and 1.5 – Conduit > 2.5” dia (SDC D, E, F)
Ip=1.0 and 1.5 – Trapezed Conduit/CT ≥ 10plf
Conduits > 2.5” attached to panels, cabinets
or other equipment shall be installed with flexible
connections.
13.6.5.6:
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21. WHAT REQUIRES BRACING….
ELECTRICAL SYSTEMS cont.:
Light Fixtures, Lighted Signs, Ceiling Fans
• Vertical supports shall be designed for 140% of operating weight with
simultaneous horizontal force of 140% of operating weight.
• Lights within a ceiling grid < 56 lbs does not need additional bracing
• Connection to structure shall allow a 360 degree range of motion if no
bracing is provided
13.6.1:
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22. WHAT REQUIRES BRACING….
HVAC SYSTEMS:
SEISMIC DESIGN CATEGORY C,D,E,F:
Ip=1.0 or 1.5 – Duct ≥ 6 Sq. Ft. or weigh > 17 lb/ft
**Provisions must be made to avoid impact with larger ducts
or mechanical components, or the ducts must be
protected in the event of such impacts
Ip=1.0 or 1.5 –Ducts supported on trapeze ≥ 10 lb/ft
Ip=1.0 or 1.5 – Inline Equipment > 75lbs , unbraced
pipes attached to inline equipment shall have flex
connections
Note: All smoke control/hazardous /
toxic ductwork requires bracing with
no size exceptions.
13.6.7:
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23. WHAT REQUIRES BRACING….
PIPING SYSTEMS:
SEISMIC DESIGN CAT. C:
Ip=1.0 – No bracing required for single hung pipe
Ip=1.5 – Piping > 2” dia.
Ip= 1.0 and 1.5 – Trapezed Piping ≥ 10plf
SEISMIC DESIGN CAT. D,E,F:
Ip=1.0 – Piping > 3” dia. (Cast Iron > 2” dia)
Ip=1.5 – Piping > 1” dia.
Ip=1.0 and 1.5 – Trapezed Piping ≥ 10plf
13.6.8:
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24. WHAT REQUIRES BRACING….
PIPING SYSTEMS cont.:
Item 3: Piping has an Rp < 4.5 per Table 13.6-1, piping
systems and attachment shall be designed for the seismic
forces and relative displacements of Section 13.3.
13.6.8.3:
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Ap Rp
25. GENERAL EXCEPTIONS TO THE RULES
12” RULE:
Must be ALL hangers on a run
Provisions are made for the piping to accommodate expected
deflections (flexes at components with relative displacements)
Assure that components does not swing and damage another utility.
13.6.5.6, 13.6.7, 13.6.8:
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26. GENERAL EXCEPTIONS TO THE RULES
12” RULE cont.:
ELECTRICAL CONDUITS AND MECHANICAL DUCTS:
• If rods are used as hangers, swivels shall be provided to
prevent inelastic bending in rods.
• Rods and anchors will have to be designed for bending due
to seismic forces in Section 13.3 if swivels are not installed
PIPING SYSTEMS:
• If rods are used as hangers, swivels, eyenuts, or other
devices to prevent any bending in the rods.
13.6.5.6, 13.6.7, 13.6.8:
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28. TYPICAL BRACING RULES - PIPING
Transverse Max Spacing : Steel/Cu = 40 ft ; Cast Iron = 20 ft
Longitudinal Max Spacing : Steel/Cu = 80 ft ; Cast Iron = 40 ft
Min Run Length = 10 ft
A Brace Within 2ft of 90deg Turn Can Work for Both Sides
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35. ROOF TOP SUPPORTS
Wind forces shall be designed per section
29.5
Wind provisions for components and
cladding is now in chapter 30
Wind provisions on equipment is part 6
Compare section 13.3 vs WIND SECTION
29.5
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36. ROOF TOP SUPPORTS
Detailing for wind design shall
be per Ch 13 (13.1.6 c)
Code compliance requires
“Positive Attachment” to
structure.
Friction resistance cannot be
used
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37. ROOF TOP EQUIPMENT
ASCE 29.5 and 29.5.1
• Wind loads shall be increased by 1.9 if your roof top equipment or
structure is on a roof that is no more than 60ft from grade.
• Studies from Texas Tech University showed that the wind gust factor is
actually 1.63 compared to 0.85 that was in ASCE 7-02. The 1.9 factor
was used to increase the pressure based on the testing (1.63/0.85 =
1.9).
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38. ROOF SCREENS DO NOT REDUCE
WIND LOADS ON STRUCTURES
Definition of mechanical screens per 2010 CBC
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FEMA 549 ATTACHMENT OF ROOFTOP EQUIPMENT IN HIGH WIND REGIONS
39. INTERSTORY DRIFT
Caused by earthquake forces
Deflection is typically 1% of
story height
MEP systems physically attached
to two different floors
Methods to mitigate effects:
- Use flex couplings/hose
- Use slotted mounts
- Spring isolators
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52. Pre-Insulated Pipe Support Integral Attachment Support
Example: 10” Pipe with 2” Insulation – Hot Water Service, 200°F
No Direct Path for Heat Loss Direct Path for Heat Loss thru Tee
Heat Loss = 100 Btu/hr Heat Loss = 2500 Btu/hr
HEAT LOSS THRU PIPE SUPPORT –
PRE-INSULATED VS INTEGRAL
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54. BRACING/SUPPORTS FOR MEP SYSTEMS
MUST BE ENGINEERED BY A PE AND
REVIEWED AND APPROVED BY THE AHJ
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55. Special Seismic Certification
13.2.2:
Manufacturer Submit Cert of Compliance for Approval to the
Registered Design Professional and Building Official
Designated (Ip=1.5) Equipment
Options : Testing / Analysis / Experiential Data
Registered Design Professional must state requirements on
Construction Documents
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57. IBC REQUIRES SPECIAL INSPECTION For
Ip=1.5 (Designated Seismic Systems)
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• Inspector needs to check
• Label of equipment
• Anchorage or mounted conforms to certificate of
compliance
58. IBC 2012 REQUIRES SPECIAL INSPECTION
MEP COMPONENTS
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SEISMIC BRACING IS PART OF INSTALLATION
THEREFORE NEEDS TO BE INSPECTED ALSO
59. Mechanical Engineer of Record Duties
Define Ip for Each Component
Determine List of Special Seismic Certifications
Review Subcontractor Submittals (Seismic Bracing and
Anchorage Submittals)
Statement of Special Inspections
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63. SEISMIC BRACING SUBMITTAL DRAWINGS
Each Seismic Location is Detailed on the Plans and
Denoted with a Location Specific I.D. Number
A Seismic Bracing Legend is Added
to Assist Installers, Inspectors, and
Reviewing Engineers in
Understanding the Constraints of
the Design
ISAT’s Structural Engineers “Wet” Stamp Each
Layout with Their Stamp from the Project State
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64. IN-HOUSE CUSTOM ENGINEERING
California Licensed PE’s, SE’s, ME’s
Custom Details and Calculations
ELECTRONIC “WET STAMPS”
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69. Example: Cable Bracing Kit
Kits Labeled with:
-Contractor Name
-Project Name
-Drawing #
-Building
Area/Floor
Cables are Pre-Tied
to custom lengths,
field adjustable,
with correct
brackets installed.
(No need to field
cut and swage
cables, no
“hunting” for
correct materials)
Correct concrete anchors, beam clamps, wood
connections, etc. are included in each kit. (No quote
surprises, No “hunting” for Anchors)
Appropriate quantity of Rod Stiffener components are included in
each kit. (No surprises in the quote (stiffeners are usually an add
with other systems), No “hunting” for materials)
Installation Details
are in each kit
Kit Production and Material Shipment…
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71. Buy American Act
ISAT’s Seismic Bracing Kits and Blue Banger
Hangers, labeled as such, are a “Domestic
Construction Material” under FAR 52.225-9 and FAR
52.225-2
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75. Typical Vibration Isolation
• Spring hangers for suspended equipment, piping,
and duct
• Un-housed spring mounts
• Seismically restrained spring mounts
• Neoprene mounts
• Neoprene hangers
• Equipment frames (e.g. cooling towers)
• Equipment inertia bases
• Riser supports (anchors, guides, and springs)
• Most material complies with Buy American Act
76. Flexible Hose and Expansion Joints
Flexible Hose
• Stainless, bronze,
• CSA certified for natural gas
• Variety of end fittings
• Custom lengths
Rubber sphere expansion joints
Expansion compensators
Seismic expansion joints
• V-loops for easy nesting
• U-loops
• Drain ports
• O2 cleaned, capped, and bagged for medical gas
• CSA certified for natural gas
PTFE bellows and hose
77. Los Angeles, CA (HQ)
San Francisco, CA
San Diego, CA
Sacramento, CA
Phoenix, AZ
Las Vegas, NV
Portland, OR
Seattle, WA
Salt Lake City, UT
Denver, CO
Charlotte, NC
Atlanta, GA
New York, NY
San Juan, Puerto Rico
ISAT Office Locations
ISAT is opening additional offices in geographic regions where
building code compliance for nonstructural seismic restraints is
becoming more stringent.
