= 5. CHAPTER 5 — LOADS | |
= 5.2 — General | |
== 5.2.1 Loads shall include self-weight; applied loads; and | |
effects of prestressing, earthquakes, restraint of volume | |
change, and differential settlement. | |
== 5.2.2 Loads and Seismic Design Categories (SDCs) shall | |
be in accordance with the general building code, or determined | |
by the building official. | |
= R5.2 — General | |
== R5.2.1 Provisions in the Code are associated with dead, | |
live, wind, and earthquake loads such as those recommended | |
in ASCE/SEI 7. The commentary to Appendix C of ASCE/ | |
SEI 7 provides service-level wind loads Wa for serviceability | |
checks; however, these loads are not appropriate for strength | |
design. | |
If the service loads specified by the general building code | |
differ from those of ASCE/SEI 7, the general building code | |
governs. However, if the nature of the loads contained in a | |
general building code differs considerably from ASCE/SEI 7 | |
loads, some provisions of this Code may need modification | |
to reflect the difference. | |
== R5.2.2 Seismic Design Categories (SDCs) in this Code | |
are adopted directly from ASCE/SEI 7. Similar designations | |
are used by the International Building Code (2018 IBC) and | |
the National Fire Protection Association (NFPA 5000 2012). | |
The BOCA National Building Code (BOCA 1999) and “The | |
Standard Building Code” (SBC 1999) used seismic performance | |
categories. The “Uniform Building Code” (IBCO | |
1997) relates seismic design requirements to seismic zones, | |
whereas editions of ACI 318 prior to 2008 related seismic | |
design requirements to seismic risk levels. Table R5.2.2 | |
correlates SDC to seismic risk terminology used in ACI | |
318 for several editions before the 2008 edition, and to the | |
various methods of assigning design requirements used in | |
the United States under the various model building codes, | |
the ASCE/SEI 7 standard, and the National Earthquake | |
Hazard Reduction Program (NEHRP 1994). | |
Design requirements for earthquake-resistant structures in | |
this Code are determined by the SDC to which the structure | |
is assigned. In general, the SDC relates to seismic hazard | |
level, soil type, occupancy, and building use. Assignment of | |
a building to an SDC is under the jurisdiction of the general | |
building code rather than this Code. | |
In the absence of a general building code that prescribes | |
earthquake effects and seismic zoning, it is the intent of | |
Committee 318 that application of provisions for earthquake- | |
resistant design be consistent with national standards | |
or model building codes such as ASCE/SEI 7, 2012 IBC, | |
and NFPA 5000. The model building codes also specify | |
overstrength factors Ωo that are related to the seismic-forceresisting | |
system used for the structure and design of certain | |
elements. | |
American Concrete Institute – Copyrighted © Material – www.concrete.org | |
PART 2: LOADS & ANALYSIS 61 | |
5 Loads | |
No further reproduction or distribution is permitted. | |
Table R5.2.2—Correlation between seismic-related terminology in model codes | |
== 5.2.3 Live load reductions shall be permitted in accordance | |
with the general building code or, in the absence of a | |
general building code, in accordance with ASCE/SEI 7. | |
[ Lanjut Ke 5.3—Load factors and combinations ... ] | |
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