DS 2-8 Earthquake Protection for Water-Based Fire ... - FM Global

2-8 Earthquake Protection
Page 28 FM Global Property Loss Prevention Data Sheets
6. Adhere to the following guidelines for attachments to concrete components:
a) Do not use powder-driven fasteners to attach sway bracing to concrete components of the structural
system.
b) When the strength of concrete is unknown, the appropriate fastener size may be selected from
Table 13 (Table 14 for metric) based on the configuration of the fastener with respect to the structural
member and the angle of the brace from the vertical. The load values given correspond to the
applied horizontal seismic load (either H or a fraction of H not less than H/2, depending on sway
bracing configuration) for the worst-case angle from the vertical for the range of angles given. In
other words, the seismic design load on the fastener must be less than the table values for the
fastener size and configuration selected. Values in Tables 13 and 14 may be used when the
following conditions are met:
i. The expansion or wedge anchors are listed for use in seismic applications by the local governing
jurisdiction based on testing that establishes parameters for anchor design.
In the United States, an example of a local governing jurisdiction would be the International
Conference of Building Officials (ICBO) evaluation services guide, and an example of an
acceptable testing protocol is the American Concrete Institute (ACI) standard 355.2, Qualification
of Post-Installed Mechanical Anchors in Concrete.
ii. A minimum edge distance of 12 times the bolt diameter (12D b) and a minimum embedment
depth of 6D b are provided, unless otherwise allowed by the manufacturer and calculations are
provided to verify adequacy.
iii. All details of the installation are in conformance with the manufacturer’s instructions and any
guidelines established by the local governing jurisdiction as part of their load ratings, including
any inspection requirements or certification of concrete strength.
iv. Verification of the capability of the structural member and the point of attachment to withstand
the anticipated load is included with the system design information.
c) Expansion anchors may be selected from a manufacturer’s product line if they meet conditions
(i) through (iv) in item b above as well as the following conditions:
i. The capacity of an anchor or group of anchors is established using ACI 318 Appendix D or a
similar local building code or standard.
ii. The relationship between actual calculated shear and tension loads, and allowable shear and
tension loads, conforms to the following equations:
(S ACT/S ALL) +(T ACT/T ALL) ≤ 1.2
(S ACT/S ALL) ≤ 1.0
(T ACT/T ALL) ≤ 1.0
where
S ACT = calculated actual shear load using Figs. 8 through 13.
S ALL = local governing jurisdiction-approved shear load.
T ACT = calculated actual tension load using Figs. 8 through 13.
T ALL = local governing jurisdiction-approved allowable tension load.
d) Cast-in-place concrete inserts may be used in place of expansion anchors if the governing
jurisdiction-approved loads for the inserts are greater than or equal to the values for the specified
expansion anchor.
7. Adhere to the following guidelines for attachments to steel structural members:
a) Make attachments to solid steel structural members using through-bolts in drilled holes, welded
studs, or connection hardware that is FM Approved for use in resisting seismic loads. Do not use
powder-driven fasteners or C-clamps (even those with retaining straps) to attach sway bracing
to steel structural members.
b) Select the appropriate fastener size from Table 15 (Table 16 for metric) for through-bolts,
corresponding to the bolt configuration with respect to the structural member, and the applied
horizontal seismic load (either H, or a fraction of H not less than H/2, depending on sway bracing
configuration), for the worst-case angle from the vertical for the range of angles given. In other
©2010 Factory Mutual Insurance Company. All rights reserved.