Basis for Design.
The primary basis for this document is the 1997
edition of the NEHRP Provisions for Seismic
Regulations for New Buildings and Other Structures
Purpose and Scope.
(FEMA 302), and the terminology and general
This document is intended to provide qualified
design procedures are incorporated by reference in
designers with the necessary criteria and guidance
this document. This document provides guidance in
for the performance-based seismic analysis and
the interpretation and implementation of the FEMA
302 provisions for the Life Safety performance
nonstructural systems and components in the
objective for all buildings, and it provides criteria for
the design and analysis of buildings with enhanced
Introduction to Seismic Design. Chapter 2
General. The criteria in this document are
applicable to all elements responsible for the design
performance-based seismic design as prescribed in
of military construction in the United States and its
Classification of Buildings. All buildings
document may be used to verify the performance
objectives of any new construction.
are classified regarding use and/or function into one
of four Seismic Use Groups indicated in Table 4-1.
Based on these seismic use groups and the applicable
and hazardous critical facilities (e.g., nuclear power
design ground motion, the buildings are further
plants, piers, wharves, dams, and liquefied gas
assigned a Seismic Design Category, as shown in
facilities) are not within the scope of this document.
Tables 4-2a and 4-2b.
The Seismic Use Group
classification dictates the seismic performance
Design Team. When use of this document
objective for the building, while the Seismic Design
is required, the selected design team will include an
engineer knowledgeable in seismic design.
engineer will be included in the facility planning
process from the beginning to provide guidance in
the selection of the appropriate seismic resisting
Two levels of ground
system. Early input and a special peer review team
motion are prescribed in this document. Both levels
are required when seismic isolation or energy
are defined in terms of spectral ordinates with
reference to the Maximum Considered Earthquake
(MCE). Contours of spectral ordinates at periods of
0.2 second and 1.0 second are delineated on the