Cover [PDF]

Standards [PDF]

Foreword [PDF]

Acknowledgements [PDF]

Dedication [PDF]

Contents [PDF]

Chapter 1 General

Chapter 2 Combinations of Loads

Chapter 3 Dead Loads, Soil Loads, and Hydrostatic Pressure

Chapter 4 Live Loads

Chapter 5 Flood Loads

Chapter 6 Reserved for Future Provisions

Chapter 7 Snow Loads

Chapter 8 Rain Loads

Chapter 9 Reserved for Future Provisions

Chapter 10 Ice Loads - Atmospheric Icing

Chapter 11 Seismic Design Criteria

Chapter 12 Seismic Design Requirements for Building Structures

Chapter 13 Seismic Design Requirements for Nonstructural Components

Chapter 14 Material Specific Seismic Design and Detailing Requirements

Chapter 15 Seismic Design Requirements for Nonbuilding Structures

Chapter 16 Seismic Response History Procedures

Chapter 17 Seismic Design Requirements for Seismically Isolated Structures

Chapter 18 Seismic Design Requirements for Structures with Damping Systems

Chapter 19 Soil-Structure Interaction for Seismic Design

Chapter 20 Site Classification Procedure for Seismic Design

Chapter 21 Site-Specific Ground Motion Procedures for Seismic Design

Chapter 22 Seismic Ground Motion Long-Period Transition and Risk Coefficient Maps

Chapter 23 Seismic Design Reference Documents

Chapter 24

Chapter 25

Chapter 26 Wind Loads: General Requirements

Chapter 27 Wind Loads on Buildings‒MWFRS (Directional Procedure)

Chapter 28 Wind Loads on Buildings‒MWFRS (Envelope Procedure)

Chapter 29 Wind Loads on Other Structures and Building Appurtenances‒MWFRS

Chapter 30 Wind Loads ‒ Components and Cladding (C&C)

Chapter 31 Wind Tunnel Procedure

Appendix 11A Quality Assurance Provisions

Appendix 11B Existing Building Provisions

Appendix C Serviceability Considerations

Appendix D Buildings Exempted from Torisional Wind Load Cases

This chapter establishes minimum design criteria for nonstructural components that are permanently attached to structures and for their supports and attachments. Where the weight of a nonstructural component is greater than or equal to 25% of the effective seismic weight, W, of the structure as defined in Section 12.7.2, the component shall be classified as a nonbuilding structure and shall be designed in accordance with Section 15.3.2.
For the purposes of this chapter, nonstructural components shall be assigned to the same seismic design category as the structure that they occupy or to which they are attached.
All components shall be assigned a component importance factor as indicated in this section. The component importance factor, Ip, shall be taken as 1.5 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 and egress stairways.
  2. The component conveys, supports, or otherwise contains toxic, highly toxic, or explosive substances where the quantity of the material exceeds a threshold quantity established by the authority having jurisdiction and is sufficient to pose a threat to the public if released.
  3. The component is in or attached to a Risk Category IV structure, and it is needed for continued operation of the facility or its failure could impair the continued operation of the facility.
  4. The component conveys, supports, or otherwise contains hazardous substances and is attached to a structure or portion thereof classified by the authority having jurisdiction as a hazardous occupancy.
All other components shall be assigned a component importance factor, Ip, equal to 1.0.
The following nonstructural components are exempt from the requirements of this section:
  1. Furniture (except storage cabinets as noted in Table 13.5-1).
  2. Temporary or movable equipment.
  3. Architectural components in Seismic Design Category B other than parapets supported by bearing walls or shear walls provided that the component importance factor, Ip, is equal to 1.0.
  4. Mechanical and electrical components in Seismic Design Category B.
  5. Mechanical and electrical components in Seismic Design Category C provided that the component importance factor, Ip, is equal to 1.0.
  6. Mechanical and electrical components in Seismic Design Categories D, E, or F where all of the following apply:
    1. The component importance factor, Ip, is equal to 1.0;
    2. The component is positively attached to the structure;
    3. Flexible connections are provided between the component and associated ductwork, piping, and conduit; and either
      1. The component weighs 400 lb (1,780 N) or less and has a center of mass located 4 ft (1.22 m) or less above the adjacent floor level; or
      2. The component weighs 20 lb (89 N) or less or, in the case of a distributed system, 5 lb/ft (73 N/m) or less.
Nonbuilding structures (including storage racks and tanks) that are supported by other structures shall be designed in accordance with Chapter 15. Where Section 15.3 requires that seismic forces be determined in accordance with Chapter 13 and values for RP are not provided in Table 13.5-1 or 13.6-1, RP shall be taken as equal to the value of R listed in Section 15. The value of ap shall be determined in accordance with footnote a of Table 13.5-1 or 13.6-1.
Where a reference document provides a basis for the earthquake-resistant design of a particular type of nonstructural component, that document is permitted to be used, subject to the approval of the authority having jurisdiction and the following conditions:
  1. The design earthquake forces shall not be less than those determined in accordance with Section 13.3.1.
  2. Each nonstructural component's seismic interactions with all other connected components and with the supporting structure shall be accounted for in the design. The component shall accommodate drifts, deflections, and relative displacements determined in accordance with the applicable seismic requirements of this standard.
  3. Nonstructural component anchorage requirements shall not be less than those specified in Section 13.4.
Where a reference document provides a basis for the earthquake-resistant design of a particular type of component, and the same reference document defines acceptance criteria in terms of allowable stresses rather than strengths, that reference document is permitted to be used. The allowable stress load combination shall consider dead, live, operating, and earthquake loads in addition to those in the reference document. The earthquake loads determined in accordance with Section 13.3.1 shall be multiplied by a factor of 0.7. The allowable stress design load combinations of Section 2.4 need not be used. The component shall also accommodate the relative displacements specified in Section 13.3.2.
Architectural, mechanical, and electrical components, supports, and attachments shall comply with the sections referenced in Table 13.2-1. These requirements shall be satisfied by one of the following methods:
  1. Project-specific design and documentation submitted for approval to the authority having jurisdiction after review and acceptance by a registered design professional.
  2. Submittal of the manufacturer's certification that the component is seismically qualified by at least one of the following:
    1. Analysis, or
    2. Testing in accordance with the alternative set forth in Section 13.2.5, or
    3. Experience data in accordance with the alternative set forth in Section 13.2.6.
Table 13.2-1 Applicable Requirements for Architectural, Mechanical, and Electrical Components: Supports and Attachments
Nonstructural Element (i.e., Component, Support, Attachment) General Design
Requirements
(Section 13.2)
Force and Displacement
Requirements
(Section 13.3)
Attachment Requirements
(Section 13.4)
Architectural Component
Requirements
(Section 13.5)
Mechanical and Electrical
Component Requirements
(Section 13.6)
Architectural components and supports and attachments for architectural components X X X
Mechanical and electrical components with IP > I X X X
Supports and attachments for mechanical and electrical components X X X


Certifications shall be provided for designated seismic systems assigned to Seismic Design Categories C through F as follows:
  1. Active mechanical and electrical equipment that must remain operable following the design earthquake ground motion shall be certified by the manufacturer as operable whereby active parts or energized components shall be certified exclusively on the basis of approved shake table testing in accordance with Section 13.2.5 or experience data in accordance with Section 13.2.6 unless it can be shown that the component is inherently rugged by comparison with similar seismically qualified components. Evidence demonstrating compliance with this requirement shall be submitted for approval to the authority having jurisdiction after review and acceptance by a registered design professional.
  2. Components with hazardous substances and assigned a component importance factor, Ip, of 1.5 in accordance with Section 13.1.3 shall be certified by the manufacturer as maintaining containment following the design earthquake ground motion by (1) analysis, (2) approved shake table testing in accordance with Section 13.2.5, or (3) experience data in accordance with Section 13.2.6. Evidence demonstrating compliance with this requirement shall be submitted for approval to the authority having jurisdiction after review and acceptance by a registered design professional.
The functional and physical interrelationship of components, their supports, and their effect on each other shall be considered so that the failure of an essential or nonessential architectural, mechanical, or electrical component shall not cause the failure of an essential architectural, mechanical, or electrical component.
The design and evaluation of components, their supports, and their attachments shall consider their flexibility and their strength.
As an alternative to the analytical requirements of Sections 13.2 through 13.6, testing shall be deemed as an acceptable method to determine the seismic capacity of components and their supports and attachments. Seismic qualification by testing based upon a nationally recognized testing standard procedure, such as ICC-ES AC 156, acceptable to the authority having jurisdiction shall be deemed to satisfy the design and evaluation requirements provided that the substantiated seismic capacities equal or exceed the seismic demands determined in accordance with Sections 13.3.1 and 13.3.2. For the testing alternative, the maximum seismic demand determined in accordance with Equation 13.3-2 is not required to exceed 3.2IPWp.
As an alternative to the analytical requirements of Sections 13.2 through 13.6, use of experience data shall be deemed as an acceptable method to determine the seismic capacity of components and their supports and attachments. Seismic qualification by experience data based upon nationally recognized procedures acceptable to the authority having jurisdiction shall be deemed to satisfy the design and evaluation requirements provided that the substantiated seismic capacities equal or exceed the seismic demands determined in accordance with Sections 13.3.1 and 13.3.2.
Where design of nonstructural components or their supports and attachments is required by Table 13.2-1, such design shall be shown in construction documents prepared by a registered design professional for use by the owner, authorities having jurisdiction, contractors, and inspectors. Such documents shall include a quality assurance plan if required by Appendix 11A.
The horizontal seismic design force (Fp) shall be applied at the component's center of gravity and distributed relative to the component's mass distribution and shall be determined in accordance with Eq. 13.3-1:

(13.3-1)
Fp is not required to be taken as greater than

Fp = 1.6SDSIpWp           (13.3-2)


and Fp shall not be taken as less than

Fp = 0.3SDSIpWp           (13.3-3)


where
Fp = seismic design force
SDS = spectral acceleration, short period, as determined from Section 11 .4.4
ap = component amplification factor that varies from 1.00 to 2.50 (select appropriate value from Table 13.5- 1 or 13.6-1)
Ip = component importance factor that varies from 1.00 to 1.50 (see Section 13.1.3)
Wp = component operating weight
Rp = component response modification factor that varies from 1.00 to 12 (select appropriate value from Table 13.5- 1 or 13.6-1)
z = height in structure of point of attachment of component with respect to the base. For items at or below the base, z shall be taken as 0. The value of z/h need not exceed 1.0
h = average roof height of structure with respect to the base

    The force (Fp) shall be applied independently in at least two orthogonal horizontal directions in combination with service loads associated with the component, as appropriate. For vertically cantilevered systems, however, the force FP shall be assumed to act in any horizontal direction. In addition, the component shall be designed for a concurrent vertical force ±0.2SDSWp. The redundancy factor, ρ, is permitted to be taken equal to 1 and the overstrength factor, Ω0, does not apply.
    EXCEPTION: The concurrent vertical seismic force need not be considered for lay-in access floor panels and lay-in ceiling panels.
    Where nonseismic loads on nonstructural components exceed Fp, such loads shall govern the strength design, but the detailing requirements and limitations prescribed in this chapter shall apply.
In lieu of the forces determined in accordance with Eq. 13.3-1, accelerations at any level are permitted to be determined by the modal analysis procedures of Section 12.9 with R = 1.0. Seismic forces shall be in accordance with Eq. 13.3-4:

(13.3-4)


where ai is the acceleration at level i obtained from the modal analysis and where Ax is the torsional amplification factor determined by Eq.12.8-14. Upper and lower limits of FP determined by Eqs. 13.3-2 and 13.3-3 shall apply.
The effects of seismic relative displacements shall be considered in combination with displacements caused by other loads as appropriate. Seismic relative displacements, DpI, shall be determined in accordance with Eq. 13.3-5:

DpI = DpIe (13.3-5)
where
Ie = the importance factor in Section 11.5.1
Dp = displacement determined in accordance with the equations set forth in Sections 13.3.2.1 and 13.3.2.2.
For two connection points on the same structure A or the same structural system, one at a height hx and the other at a height hy, Dp shall be determined as

           Dp = ΔxA - ΔyA          (13.3-6)


    Alternatively, Dp is permitted to be determined using modal procedures described in Section 12.9, using the difference in story deflections calculated for each mode and then combined using appropriate modal combination procedures. Dp is not required to be taken as greater than

(13.3-7)
For two connection points on separate structures A and B or separate structural systems, one at a height hx and the other at a height hy, DP shall be determined as

(13.3-8)


    DP is not required to be taken as greater than

(13.3-9)
where
DP = relative seismic displacement that the component must be designed to accommodate
δxA = deflection at building level x of structure A, determined in accordance with Eq. (12.8-15)
δyA = deflection at building level y of structure A, determined in accordance with Eq. (12.8-15) .
δyB = deflection at building level y of structure B, determined in accordance with Eq. (12.8-15).
hx = height of level x to which upper connection point is attached
hy = height of level y to which lower connection point isattached
ΔaA = allowable story drift for structure A as defined in Table 12.12-1
ΔaB = allowable story drift for structure B as defined in Table 12.12-1
hsx = story height used in the definition of the allowable drift Δa in Table 12.12-1. Note that Δa/hsx = the drift index.

    The effects of seismic relative displacements shall be considered in combination with displacements caused by other loads as appropriate.
Nonstructural components and their supports shall be attached (or anchored) to the structure in accordance with the requirements of this section, and the attachment shall satisfy the requirements for the parent material as set forth elsewhere in this standard.
    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 connections shall be designed and constructed for the component forces where they control the design of the elements or their connections. The component forces shall be those determined in Section 13.3.1. The design documents shall include sufficient information relating to the attachments to verify compliance with the requirements of this section.
The force in the attachment shall be determined based on the prescribed forces and displacements for the component as determined in Sections 13.3.1 and 13.3.2, except that Rp shall not be taken as larger than 6.
Anchors in concrete shall be designed in accordance with Appendix D of ACI 318.
Anchors in masonry shall be designed in accordance with TMS 402/ACI 530/ASCE 5. Anchors shall be designed to be governed by the tensile or shear strength of a ductile steel element.
    EXCEPTION: Anchors shall be permitted to be designed so that the support that the anchor is connecting to the structure undergoes ductile yielding at a load level corresponding to anchor forces not greater than their design strength, or the minimum design strength of the anchors shall be at least 2.5 times the factored forces transmitted by the component.
Post-installed anchors in concrete shall be prequalified for seismic applications in accordance with ACI 355.2 or other approved qualification procedures. Post-installed anchors in masonry shall be prequalified for seismic applications in accordance with approved qualification procedures.
Determination of forces in attachments shall take into account the expected conditions of installation including eccentricities and prying effects.
Determination of force distribution of multiple attachments at one location shall take into account the stiffness and ductility of the component, component supports, attachments, and structure and the ability to redistribute loads to other attachments in the group. Designs of anchorage in concrete in accordance with Appendix D of ACI 318 shall be considered to satisfy this requirement.
Power actuated fasteners in concrete or steel shall not be used for sustained tension loads or for brace applications in Seismic Design Categories D, E, or F unless approved for seismic loading. Power actuated fasteners in masonry are not permitted unless approved for seismic loading.
   EXCEPTIONS:
  1. Power-actuated fasteners in concrete used for support of acoustical tile or lay-in panel suspended ceiling applications and distributed systems where the service load on any individual fastener does not exceed 90 lb (400 N).
  2. Power actuated fasteners in steel where the service load on any individual fastener does not exceed 250 lb (1,112 N).
Friction clips in Seismic Design Categories D, E, or F shall not be used for supporting sustained loads in addition to resisting seismic forces. C-type beam and large flange clamps are permitted for hangers provided they are equipped with restraining straps equivalent to those specified in NFPA 13, Section 9.3.7. Lock nuts or equivalent shall be provided to prevent loosening of threaded connections.
Architectural components, and their supports and attachments, shall satisfy the requirements of this section. Appropriate coefficients shall be selected from Table 13.5-1.
    EXCEPTION: Components supported by chains or otherwise suspended from the structure are not required to satisfy the seismic force and relative displacement requirements provided they meet all of the following criteria:
  1. The design load for such items shall be equal to 1.4 times the operating weight acting down with a simultaneous horizontal load equal to 1.4 times the operating weight. The horizontal load shall be applied in the direction that results in the most critical loading for design.
  2. Seismic interaction effects shall be considered in accordance with Section 13.2.3.
  3. The connection to the structure shall allow a 360° range of motion in the horizontal plane.
Table 13.5-1 Coefficients for Architectural Components
Architectural Component apa Rp Ω0c
Interior Nonstructural Walls and Partitionsb

Plain (unreinforced) masonry walls

All other walls and partitions


1

1








Cantilever Elements (Unbraced or Braced to Structural Frame below Its Center of Mass)

Parapets and cantilever interior nonstructural walls

Chimneys where laterally braced or supported by the structural frame















Cantilever Elements (Braced to Structural Frame above Its Center of Mass)

Parapets

Chimneys

Exterior Nonstructural Wallsb


1

1

1b












Exterior Nonstructural Wall Elements and Connectionsb

Wall element

Body of wall panel connections

Fasteners of the connecting system


1

1







1






Veneer

Limited deformability elements and attachments

Low deformability elements and attachments


1

1








Penthouses (except where framed by an extension of the building frame)
Ceilings

All


1




Cabinets

    Permanent floor-supported storage cabinets over 6 feet (1829 mm) tall, including contents

    Permanent floor-supported library shelving, book stacks, and bookshelves over 6 feet (1829 mm) tall, including contents

1


1









Laboratory equipment 1
Access Floors

    Special access floors (designed in accordance with Section 13.5.7.2)

    All other


1

1








Appendages and Ornamentations
Signs and Billboards 3
Other Rigid Components

High deformability elements and attachments

Limited deformability elements and attachments

Low deformability materials and attachments


1

1

1












Other Flexible Components

High deformability elements and attachments

Limited deformability elements and attachments

Low deformability materials and attachments


















Egress stairways not part of the building structure 1

aA lower value for ap shall not be used unless justified by detailed dynamic analysis. The value for ap shall not be less than 1. The value of ap = 1 is for rigid components and rigidly attached components. The value of ap = 2½ is for flexible components and flexibly attached components.
bWhere flexible diaphragms provide lateral support for concrete or masonry walls and partitions, the design forces for anchorage to the diaphragm shall be as specified in Section 12.11.2.
cOverstrength as required for anchorage to concrete. See Section 12.4.3 for inclusion of overstrength factor in seismic load effect.
All architectural components, and their supports and attachments, shall be designed for the seismic forces defined in Section 13.3.1.
    Architectural components that could pose a life-safety hazard shall be designed to accommodate the seismic relative displacement requirements of Section 13.3.2. Architectural components shall be designed considering vertical deflection due to joint rotation of cantilever structural members.
Exterior nonstructural wall panels or elements that are attached to or enclose the structure shall be designed to accommodate the seismic relative displacements defined in Section 13.3.2 and movements due to temperature changes. Such elements shall be supported by means of positive and direct structural supports or by mechanical connections and fasteners in accordance with the following requirements:
  1. Connections and panel joints shall allow for the story drift caused by relative seismic displacements (Dp) determined in Section 13.3.2, or 0.5 in. (13 mm), whichever is greatest.
  2. Connections to permit movement in the plane of the panel for story drift shall be sliding connections using slotted or oversize holes, connections that permit movement by bending of steel, or other connections that provide equivalent sliding or ductile capacity.
  3. The connecting member itself shall have sufficient ductility and rotation capacity to preclude fracture of the concrete or brittle failures at or near welds.
  4. All fasteners in the connecting system such as bolts, inserts, welds, and dowels, and the body of the connectors shall be designed for the force (Fp) determined by Section 13.3.1 with values of RP and ap taken from Table 13.5-1 applied at the center of mass of the panel.
  5. Where anchorage is achieved using flat straps embedded in concrete or masonry, such straps shall be attached to or hooked around reinforcing steel or otherwise terminated so as to effectively transfer forces to the reinforcing steel or to assure that pullout of anchorage is not the initial failure mechanism.
Glass in glazed curtain walls and storefronts shall be designed and installed in accordance with Section 13.5.9.
Transverse or out-of-plane bending or deformation of a component or system that is subjected to forces as determined in Section 13.5.2 shall not exceed the deflection capability of the component or system.
Suspended ceilings shall be in accordance with this section.
    EXCEPTIONS:
  1. Suspended ceilings with areas less than or equal to 144 ft2 (13.4 m2) that are surrounded by walls or soffits that are laterally braced to the structure above are exempt from the requirements of this section.
  2. Suspended ceilings constructed of screw- or nail-attached gypsum board on one level that are surrounded by and connected to walls or soffits that are laterally braced to the structure above are exempt from the requirements of this section.
The weight of the ceiling, Wp, shall include the ceiling grid; ceiling tiles or panels; light fixtures if attached to, clipped to, or laterally supported by the ceiling grid; and other components that are laterally supported by the ceiling. Wp shall be taken as not less than 4 psf (192 N/m2).
    The seismic force, Fp, shall be transmitted through the ceiling attachments to the building structural elements or the ceiling-structure boundary.
Unless designed in accordance with Section 13.5.6.3, or seismically qualified in accordance with Section 13.2.5 or 13.2.6, acoustical tile or lay-in panel ceilings shall be designed and constructed in accordance with this section.
Acoustical tile or lay-in panel ceilings in structures assigned to Seismic Design Category C shall be designed and installed in accordance with ASTM C635, ASTM C636, and ASTM E580, Section 4-Seismic Design Category C.
Acoustical tile or lay-in panel ceilings in Seismic Design Categories D, E, and F shall be designed and installed in accordance with ASTM C635, ASTM C636, and ASTM E580, Section 5-Seismic Design Categories D, E, and F as modified by this section.
    Acoustical tile or lay-in panel ceilings shall also comply with the following:
  1. The width of the perimeter supporting closure angle or channel shall be not less than 2.0 in. (50 mm). Where perimeter supporting clips are used, they shall be qualified in accordance with approved test criteria. In each orthogonal horizontal direction, one end of the ceiling grid shall be attached to the closure angle or channel. The other end in each horizontal direction shall have a 0.75 in. (19 mm) clearance from the wall and shall rest upon and be free to slide on a closure angle or channel.
  2. For ceiling areas exceeding 2,500 ft2 (232 m2), a seismic separation joint or full height partition that breaks the ceiling up into areas not exceeding 2,500 ft2 (232 m2), each with a ratio of the long to short dimension less than or equal to 4, shall be provided unless structural analyses are performed of the ceiling bracing system for the prescribed seismic forces that demonstrate ceiling penetrations and closure angles or channels provide sufficient clearance to accommodate the anticipated lateral displacement. Each area shall be provided with closure angles or channels in accordance with Section 13.5.6.2.2.a and horizontal restraints or bracing.
As an alternate to providing large clearances around sprinkler system penetrations through ceilings, the sprinkler system and ceiling grid are permitted to be designed and tied together as an integral unit. Such a design shall consider the mass and flexibility of all elements involved, including the ceiling, sprinkler system, light fixtures, and mechanical (HVAC) appurtenances. Such design shall be performed by a registered design professional.
The weight of the access floor, Wp, shall include the weight of the floor system, 100% of the weight of all equipment fastened to the floor, and 25% of the weight of all equipment supported by but not fastened to the floor. The seismic force, Fp, shall be transmitted from the top surface of the access floor to the supporting structure.
    Overturning effects of equipment fastened to the access floor panels also shall be considered. The ability of "slip on" heads for pedestals shall be evaluated for suitability to transfer overturning effects of equipment.
    Where checking individual pedestals for overturning effects, the maximum concurrent axial load shall not exceed the portion of Wp assigned to the pedestal under consideration.
Access floors shall be considered to be "special access floors" if they are designed to comply with the following considerations:
  1. Connections transmitting seismic loads consist of mechanical fasteners, anchors satisfying the requirements of Appendix D of ACI 318, welding, or bearing. Design load capacities comply with recognized design codes and/or certified test results.
  2. Seismic loads are not transmitted by friction, power actuated fasteners, adhesives, or by friction produced solely by the effects of gravity.
  3. The design analysis of the bracing system includes the destabilizing effects of individual members buckling in compression.
  4. Bracing and pedestals are of structural or mechanical shapes produced to ASTM specifications that specify minimum mechanical properties. Electrical tubing shall not be used.
  5. Floor stringers that are designed to carry axial seismic loads and that are mechanically fastened to the supporting pedestals are used.
Partitions that are tied to the ceiling and all partitions greater than 6 ft (1.8 m) in height shall be laterally braced to the building structure. Such bracing shall be independent of any ceiling lateral force bracing. Bracing shall be spaced to limit horizontal deflection at the partition head to be compatible with ceiling deflection requirements as determined in Section 13.5.6 for suspended ceilings and elsewhere in this section for other systems.
   EXCEPTION: Partitions that meet all of the following conditions:
  1. The partition height does not exceed 9 ft (2,740 mm).
  2. The linear weight of the partition does not exceed the product of 10 lb (0.479 kN) times the height (ft or m) of the partition.
  3. The partition horizontal seismic load does not exceed 5 psf (0.24 kN/m2).
Glass in glazed partitions shall be designed and installed in accordance with Section 13.5.9.
Glass in glazed curtain walls, glazed storefronts, and glazed partitions shall meet the relative displacement requirement of Eq. 13.5-1:

Δfallout ≥ 1.25IeDp         (13.5-1)

or 0.5 in. (13 mm), whichever is greater where:
Δfallout = the relative seismic displacement (drift) at which glass
fallout from the curtain wall, storefront wall, or partition
occurs (Section 13.5.9.2)
Dp = the relative seismic displacement that the component
must be designed to accommodate (Section 13.3.2.1).
Dp shall be applied over the height of the glass component under consideration
Ie = the importance factor determined in accordance with Section 11.5 .1


    EXCEPTIONS:
  1. Glass with sufficient clearances from its frame such that physical contact between the glass and frame will not occur at the design drift, as demonstrated by Eq. 13.5-2, need not comply with this requirement:

    Dclear ≥ 1.25Dp           (13.5-2)
    where
    Dclear = relative horizontal ( drift) displacement, measured over the height of the glass panel under consideration, which causes initial glass-to-frame contact. For rectangular glass panels within a rectangular wall frame

    where
    hp = the height of the rectangular glass panel
    bp = the width of the rectangular glass panel
    c1 = the average of the clearances (gaps) on both sides
    between the vertical glass edges and the frame
    c2 = the average of the clearances (gaps) top and bottom
    between the horizontal glass edges and the frame
  2. Fully tempered monolithic glass in Risk Categories I, II, and III located no more than 10 ft (3 m) above a walking surface need not comply with this requirement.
  3. Annealed or heat-strengthened laminated glass in single thickness with interlayer no less than 0.030 in. (0.76 mm) that is captured mechanically in a wall system glazing pocket, and whose perimeter is secured to the frame by a wet-glazed gunable curing elastomeric sealant perimeter bead of 0.5 in. (13 mm) minimum glass contact width, or other approved anchorage system need not comply with this requirement.
Δfallout, the drift causing glass fallout from the curtain wall, storefront, or partition shall be determined in accordance with AAMA 501.6 or by engineering analysis.
Mechanical and electrical components and their supports shall satisfy the requirements of this section. The attachment of mechanical and electrical components and their supports to the structure shall meet the requirements of Section 13.4. Appropriate coefficients shall be selected from Table 13.6-1.
    EXCEPTION: Light fixtures, lighted signs, and ceiling fans not connected to ducts or piping, which are supported by chains or otherwise suspended from the structure, are not required to satisfy the seismic force and relative displacement requirements provided they meet all of the following criteria:
  1. The design load for such items shall be equal to 1.4 times the operating weight acting down with a simultaneous horizontal load equal to 1.4 times the operating weight. The horizontal load shall be applied in the direction that results in the most critical loading for the design.
  2. Seismic interaction effects shall be considered in accordance with Section 13.2.3.
  3. The connection to the structure shall allow a 360° range of motion in the horizontal plane.
    Where design of mechanical and electrical components for seismic effects is required, consideration shall be given to the dynamic effects of the components, their contents, and where appropriate, their supports and attachments. In such cases, the interaction between the components and the supporting structures, including other mechanical and electrical components, shall also be considered.
Table 13.6-1 Seismic Coefficients for Mechanical and Electrical Components
MECHANICAL AND ELECTRICAL COMPONENTS apa Rpb Ω0c
Air-side HVAC, fans, air handlers, air conditioning units, cabinet heaters, air distribution boxes, and other mechanical components constructed of sheet metal framing. 6
Wet-side HVAC, boilers, furnaces, atmospheric tanks and bins, chillers, water heaters, heat exchangers, evaporators, air separators, manufacturing or process equipment, and other mechanical components constructed of high-deformability materials. 1
Engines, turbines, pumps, compressors, and pressure vessels not supported on skirts and not within the scope of Chapter 15. 1
Skirt-supported pressure vessels not within the scope of Chapter 15.
Elevator and escalator components. 1
Generators, batteries, inverters, motors, transformers, and other electrical components constructed of high-deformability materials. 1
Motor control centers, panel boards, switch gear, instrumentation cabinets, and other components constructed of sheet metal framing. 6
Communication equipment, computers, instrumentation, and controls. 1
Roof-mounted stacks, cooling and electrical towers laterally braced below their center of mass. 3
Roof-mounted stacks, cooling and electrical towers laterally braced above their center of mass. 1
Lighting fixtures. 1
Other mechanical or electrical components. 1
VIBRATION ISOLATED COMPONENTS AND SYSTEMSb
Components and systems isolated using neoprene elements and neoprene isolated floors with built-in or separate elastomeric snubbing devices or resilient perimeter stops.
Spring-isolated components and systems and vibration-isolated floors closely restrained using built-in or separate elastomeric snubbing devices or resilient perimeter stops. 2
Internally isolated components and systems. 2
Suspended vibration-isolated equipment including in-line duct devices and suspended internally isolated components.
DISTRIBUTION SYSTEMS
Piping in accordance with ASME B31, including in-line components with joints made by welding or brazing. 12
Piping in accordance with ASME B31, including in-line components, constructed of high- or limited-deformability materials, with joints made by threading, bonding, compression couplings, or grooved couplings. 6
Piping and tubing not in accordance with ASME B31, including in-line components, constructed of high-deformability materials, with joints made by welding or brazing. 9
Piping and tubing not in accordance with ASME B31, including in-line components, constructed of high- or limited-deformability materials, with joints made by threading, bonding, compression couplings, or grooved couplings.
Piping and tubing constructed of low-deformability materials, such as cast iron, glass, and nonductile plastics. 3
Ductwork, including in-line components, constructed of high-deformability materials, with joints made by welding or brazing. 9
Ductwork, includin in-line components, constructed of high- or lirited-deformability materials with joint s made by means other than welding or brazing. 6
Ductwork, including in-line components, constructed of low-deformability materials, such as cast iron, glass, and nonductile plastics. 3
Electrical conduit and cable trays 6
Bus ducts 1
Plumbing 1
Manufacturing or process conveyors (nonpersonnel). 3


aA lower value for ap is permitted where justified by detailed dynamic analyses. The value for ap shall not be less than 1. The value of ap equal to 1 is for rigid components and rigidly attached components. The value of ap equal to 2½ is for flexible components and flexibly attached components.
bComponents mounted on vibration isolators shall have a bumper restraint or snubber in each horizontal direction. The design force shall be taken as 2Fp if the nominal clearance (air gap) between the equipment support frame and restraint is greater than 0.25 in. If the nominal clearance specified on the construction documents is not greater than 0.25 in., the design force is permitted to be taken as Fp.
cOverstrength as required for anchorage to concrete. See Section 12.4.3 for inclusion of overstrength factor in seismic load effect.
The fundamental period of the nonstructural component (including its supports and attachment to the structure), Tp, shall be determined by the following equation provided that the component, supports, and attachment can be reasonably represented analytically by a simple spring and mass single degree-of-freedom system:
(13.6-1)
where
Tp = component fundamental period
Wp = component operating weight
g = gravitational acceleration
Kp = combined stiffness of the component, supports and attachments, determined in terms of load per unit deflection at the center of gravity of the component

    Alternatively, the fundamental period of the component, Tp, in seconds is permitted to be determined from experimental test data or by a properly substantiated analysis.
HVAC ductwork shall meet the requirements of Section 13.6.7. Piping systems shall meet the requirements of Section 13.6.8. Boilers and vessels shall meet the requirements of Section 13.6.9. Elevators shall meet the requirements of Section 13.6.10. All other mechanical components shall meet the requirements of Section 13.6.11. Mechanical components with IP greater than 1.0 shall be designed for the seismic forces and relative displacements defined in Sections 13.3.1 and 13.3.2 and shall satisfy the following additional requirements:
  1. Provision shall be made to eliminate seismic impact for components vulnerable to impact, for components constructed of nonductile materials, and in cases where material ductility will be reduced due to service conditions (e.g., low temperature applications).
  2. The possibility of loads imposed on components by attached utility or service lines, due to differential movement of support points on separate structures, shall be evaluated.
  3. Where piping or HVAC ductwork components are attached to structures that could displace relative to one another and for isolated structures where such components cross the isolation interface, the components shall be designed to accommodate the seismic relative displacements defined in Section 13.3.2.
Electrical components with Ip greater than 1.0 shall be designed for the seismic forces and relative displacements defined in Sections 13.3.1 and 13.3.2 and shall satisfy the following additional requirements:
  1. Provision shall be made to eliminate seismic impact between components.
  2. Loads imposed on the components by attached utility or service lines that are attached to separate structures shall be evaluated.
  3. Batteries on racks shall have wraparound restraints to ensure that the batteries will not fall from the racks. Spacers shall be used between restraints and cells to prevent damage to cases. Racks shall be evaluated for sufficient lateral load capacity.
  4. Internal coils of dry type transformers shall be positively attached to their supporting substructure within the transformer enclosure.
  5. Electrical control panels, computer equipment, and other items with slide-out components shall have a latching mechanism to hold the components in place.
  6. Electrical cabinet design shall comply with the applicable National Electrical Manufacturers Association (NEMA) standards. Cutouts in the lower shear panel that have not been made by the manufacturer and reduce significantly the strength of the cabinet shall be specifically evaluated.
  7. The attachments for additional external items weighing more than 100 lb (445 N) shall be specifically evaluated if not provided by the manufacturer.
  8. Where conduit, cable trays, or similar electrical distribution components are attached to structures that could displace relative to one another and for isolated structures where such components cross the isolation interface, the components shall be designed to accommodate the seismic relative displacements defined in Section 13.3.2.
Mechanical and electrical component supports (including those with Ip = 1.0) and the means by which they are attached to the component shall be designed for the forces and displacements determined in Sections 13.3.1 and 13.3.2. Such supports include structural members, braces, frames, skirts, legs, saddles, pedestals, cables, guys, stays, snubbers, tethers, and elements forged or cast as a part of the mechanical or electrical component.
If standard supports, for example, ASME B31, NFPA 13, or MSS SP-58, or proprietary supports are used, they shall be designed by either load rating (i.e., testing) or for the calculated seismic forces. In addition, the stiffness of the support, where appropriate, shall be designed such that the seismic load path for the component performs its intended function.
Component supports shall be designed to accommodate the seismic relative displacements between points of support determined in accordance with Section 13.3.2.
The means by which supports are attached to the component, except where integral (i.e., cast or forged), shall be designed to accommodate both the forces and displacements determined in accordance with Sections 13.3.1 and 13.3.2. If the value of IP = 1.5 for the component, the local region of the support attachment point to the component shall be evaluated for the effect of the load transfer on the component wall.
The materials comprising supports and the means of attachment to the component shall be constructed of materials suitable for the application, including the effects of service conditions, for example, low temperature applications. Materials shall be in conformance with a nationally recognized standard.
The following additional requirements shall apply to mechanical and electrical component supports:
  1. Seismic supports shall be constructed so that support engagement is maintained.
  2. Reinforcement (e.g., stiffeners or Belleville washers) shall be provided at bolted connections through sheet metal equipment housings as required to transfer the equipment seismic loads specified in this section from the equipment to the structure. Where equipment has been certified per Section 13.2.2, 13.2.5, or 13.2.6, anchor bolts or other fasteners and associated hardware as included in the certification shall be installed in conformance with the manufacturer's instructions. For those cases where no certification exists or where instructions for such reinforcement are not provided, reinforcement methods shall be as specified by a registered design professional or as approved by the authority having jurisdiction.
  3. Where weak-axis bending of cold-formed steel supports is relied on for the seismic load path, such supports shall be specifically evaluated.
  4. Components mounted on vibration isolators shall have a bumper restraint or snubber in each horizontal direction, and vertical restraints shall be provided where required to resist overturning. Isolator housings and restraints shall be constructed of ductile materials. (See additional design force requirements in footnote b to Table 13.6-1.) A viscoelastic pad or similar material of appropriate thickness shall be used between the bumper and components to limit the impact load.
  5. Where post-installed mechanical anchors are used for non-vibration isolated mechanical equipment rated over 10 hp (7.45 kW), they shall be qualified in accordance with ACI 355.2.
  6. For piping, boilers, and pressure vessels, attachments to concrete shall be suitable for cyclic loads.
  7. For mechanical equipment, drilled and grouted-in-place anchors for tensile load applications shall use either expansive cement or expansive epoxy grout.
Raceways shall be designed for seismic forces and seismic relative displacements as required in Section 13.3. Conduit greater than 2.5 in. (64 mm) trade size and attached to panels, cabinets, or other equipment subject to seismic relative displacement, Dp, shall be provided with flexible connections or designed for seismic forces and seismic relative displacements as required in Section 13.3.
    EXCEPTIONS:
  1. Design for the seismic forces and relative displacements of Section 13.3 shall not be required for raceways where either:
    1. Trapeze assemblies are used to support raceways and the total weight of the raceway supported by trapeze assemblies is less than 10 lb/ft (146 N/m), or
    2. The raceway is supported by hangers and each hanger in the raceway run is 12 in. (305 mm) or less in length from the raceway support point to the supporting structure. Where rod hangers are used, they shall be equipped with swivels to prevent inelastic bending in the rod.
  2. Design for the seismic forces and relative displacements of Section 13.3 shall not be required for conduit, regardless of the value of Ip, where the conduit is less than 2.5 in. (64 mm) trade size.
At the interface of adjacent structures or portions of the same structure that may move independently, utility lines shall be provided with adequate flexibility to accommodate the anticipated differential movement between the portions that move independently. Differential displacement calculations shall be determined in accordance with Section 13.3.2.
     The possible interruption of utility service shall be considered in relation to designated seismic systems in Risk Category IV as defined in Table 1.5-1. Specific attention shall be given to the vulnerability of underground utilities and utility interfaces between the structure and the ground where Site Class E or F soil is present, and where the seismic coefficient SDS at the underground utility or at the base of the structure is equal to or greater than 0.33.
HVAC and other ductwork shall be designed for seismic forces and seismic relative displacements as required in Section 13.3. Design for the displacements across seismic joints shall be required for ductwork with Ip = 1.5 without consideration of the exceptions below.
     EXCEPTIONS:The following exceptions pertain to ductwork not designed to carry toxic, highly toxic, or flammable gases or used for smoke control:
  1. Design for the seismic forces and relative displacements of Section 13.3 shall not be required for ductwork where either:
    1. Trapeze assemblies are used to support ductwork and the total weight of the ductwork supported by trapeze assemblies is less than 10 lb/ft (146 N/m); or
    2. The ductwork is supported by hangers and each hanger in the duct run is 12 in. (305 mm) or less in length from the duct support point to the supporting structure. Where rod hangers are used, they shall be equipped with swivels to prevent inelastic bending in the rod.
  2. Design for the seismic forces and relative displacements of Section 13.3 shall not be required where provisions are made to avoid impact with larger ducts or mechanical components or to protect the ducts in the event of such impact, and HVAC ducts have a cross-sectional area of less than 6 ft2 (0.557 m2), or weigh 17 lb/ft (248 N/m) or less.
    HVAC duct systems fabricated and installed in accordance with standards approved by the authority having jurisdiction shall be deemed to meet the lateral bracing requirements of this section.
    Components that are installed in-line with the duct system and have an operating weight greater than 75 lb (334 N), such as fans, heat exchangers, and humidifiers, shall be supported and laterally braced independent of the duct system and such braces shall meet the force requirements of Section 13.3.1. Appurtenances such as dampers, louvers, and diffusers shall be positively attached with mechanical fasteners. Unbraced piping attached to in-line equipment shall be provided with adequate flexibility to accommodate the seismic relative displacements of Section 13.3.2.
Unless otherwise noted in this section, piping systems shall be designed for the seismic forces and seismic relative displacements of Section 13.3. ASME pressure piping systems shall satisfy the requirements of Section 13.6.8.1. Fire protection sprinkler piping shall satisfy the requirements of Section 13.6.8.2. Elevator system piping shall satisfy the requirements of Section 13.6.10.
    Where other applicable material standards or recognized design bases are not used, piping design including consideration of service loads shall be based on the following allowable stresses:
  1. For piping constructed with ductile materials (e.g., steel, aluminum, or copper), 90% of the minimum specified yield strength.
  2. For threaded connections in piping constructed with ductile materials, 70% of the minimum specified yield strength.
  3. For piping constructed with nonductile materials (e.g., cast iron or ceramics), 10% of the material minimum specified tensile strength.
  4. For threaded connections in piping constructed with nonductile materials, 8% of the material minimum specified tensile strength.
    Piping not detailed to accommodate the seismic relative displacements at connections to other components shall be provided with connections having sufficient flexibility to avoid failure of the connection between the components.
Pressure piping systems, including their supports, designed and constructed in accordance with ASME B31 shall be deemed to meet the force, displacement, and other requirements of this section. In lieu of specific force and displacement requirements provided in ASME B31, the force and displacement requirements of Section 13.3 shall be used. Materials meeting the toughness requirements of ASME B31 shall be considered high-deformability materials.
Fire protection sprinkler piping, pipe hangers, and bracing designed and constructed in accordance with NFPA 13 shall be deemed to meet the force and displacement requirements of this section. The exceptions of Section 13.6.8.3 shall not apply.
Design of piping systems and attachments for the seismic forces and relative displacements of Section 13.3 shall not be required where one of the following conditions apply:
  1. Trapeze assemblies are used to support piping whereby no single pipe exceeds the limits set forth in 3a, 3b, or 3c below and the total weight of the piping supported by the trapeze assemblies is less than 10 lb/ft (146 N/m).
  2. The piping is supported by hangers and each hanger in the piping run is 12 in. (305 mm) or less in length from the top of the pipe to the supporting structure. Where pipes are supported on a trapeze, the trapeze shall be supported by hangers having a length of 12 in. (305 mm) or less. Where rod hangers are used, they shall be equipped with swivels, eye nuts, or other devices to prevent bending in the rod.
  3. Piping having an Rp in Table 13.6-1 of 4.5 or greater is used and provisions are made to avoid impact with other structural or nonstructural components or to protect the piping in the event of such impact and where the following size requirements are satisfied:
    1. For Seismic Design Category C where Ip is greater than 1.0, the nominal pipe size shall be 2 in. (50 mm) or less.
    2. For Seismic Design Categories D, E, or F and Ip is greater than 1.0, the nominal pipe size shall be 1 in. (25 mm) or less.
    3. For Seismic Design Categories D, E, or F where Ip = 1.0, the nominal pipe size shall be 3 in. (80 mm) or less.
Boilers or pressure vessels designed and constructed in accordance with ASME BPVC shall be deemed to meet the force, displacement, and other requirements of this section. In lieu of the specific force and displacement requirements provided in the ASME BPVC, the force and displacement requirements of Sections 13.3.1 and 13.3.2 shall be used. Materials meeting the toughness requirements of ASME BPVC shall be considered high-deformability materials. Other boilers and pressure vessels designated as having an Ip = 1.5, but not designed and constructed in accordance with the requirements of ASME BPVC, shall comply with the requirements of Section 13.6.11.
Elevators and escalators designed in accordance with the seismic requirements of ASME A17.1 shall be deemed to meet the seismic force requirements of this section, except as modified in the following text. The exceptions of Section 13.6.8.3 shall not apply to elevator piping.
Escalators, elevators, and hoistway structural systems shall be designed to meet the force and displacement requirements of Sections 13.3.1 and 13.3.2.
Elevator equipment and controller supports and attachments shall be designed to meet the force and displacement requirements of Sections 13.3.1 and 13.3.2.
Elevators operating with a speed of 150 ft/min (46 m/min) or greater shall be provided with seismic switches. Seismic switches shall provide an electric signal indicating that structural motions are of such a magnitude that the operation of the elevators may be impaired. Seismic switches in accordance with Section 8.4.10.1.2 of ASME A17.1 shall be deemed to meet the requirements of this section.
    EXCEPTION: In cases where seismic switches cannot be located near a column in accordance with ASME A17.1, they shall have two horizontal axes of sensitivity and have a trigger level set to 20% of the acceleration of gravity where located at or near the base of the structure and 50% of the acceleration of gravity in all other locations.
    Upon activation of the seismic switch, elevator operations shall conform to requirements of ASME A17.1, except as noted in the following text.
    In facilities where the loss of the use of an elevator is a life-safety issue, the elevator shall only be used after the seismic switch has triggered provided that
  1. The elevator shall operate no faster than the service speed, and
  2. Before the elevator is occupied, it is operated from top to bottom and back to top to verify that it is operable.
Retainer plates are required at the top and bottom of the car and counterweight.
Mechanical and electrical components, including conveyor systems, not designed and constructed in accordance with the reference documents in Chapter 23 shall meet the following:
  1. Components, their supports and attachments shall comply with the requirements of Sections 13.4, 13.6.3, 13.6.4, and 13.6.5.
  2. For mechanical components with hazardous substances and assigned a component importance factor, Ip, of 1.5 in accordance with Section 13.1.3 and for boilers and pressure vessels not designed in accordance with ASME BPVC, the design strength for seismic loads in combination with other service loads and appropriate environmental effects shall be based on the following material properties:
    1. For mechanical components constructed with ductile materials (e.g., steel, aluminum, or copper), 90% of the minimum specified yield strength.
    2. For threaded connections in components constructed with ductile materials, 70% of the minimum specified yield strength.
    3. For mechanical components constructed with nonductile materials (e.g., plastic, cast iron, or ceramics), 10% of the material minimum specified tensile strength.
    4. For threaded connections in components constructed with nonductile materials, 8% of the material minimum specified tensile strength.
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