critical to mission continuation of the activity (there
with each performance objective are presented in
is no redundant back-up facility on- or off-site) as
Table 4-4, and each of the analytical procedures is
determined by the Commanding Officer at the
described in Chapter 5.
These procedures are
activity and/or the Major Claimant.
considered to provide acceptable analytical results for
most low-rise (i.e., six stories or less) regular
Seismic Use Groups IIIH
buildings. Chapter 5 provides guidance regarding the
buildings are those containing substantial quantities
limitations of these minimum analytical procedures,
of hazardous substances that could be dangerous to
as well as when more rigorous analyses are required.
the safety of the public, if released.
It should be noted that most military buildings are
Group II. Seismic Use Group II buildings
Occupancy) that have Performance Objective 1A
are those that constitute a substantial public hazard
(Life Safety). For these buildings, the basic design
because of the occupancy or use of the building.
approach used in this document prescribes a linear
elastic (ELF or modal analysis) procedure that has
Group I. Seismic Use Group I buildings are
not changed from previous criteria. The most basic
those that are not assigned to Seismic Use Groups II
change from previous design procedures is that the
comparison of the demand of the design loads to the
structural component capacity is performed at the
Hazardous Critical Facilities.
strength level, rather than working or allowable
facilities (e.g., nuclear power plants, dams, and LNG
facilities) are not included within the scope of this
document, but are covered by other publications or
For any facilities housing
criteria for each of the performance objectives and
hazardous items not covered by criteria in this
the applicable analytical procedures are prescribed in
document, guidance should be requested from
Chapter 6. Numerical acceptance limits for specific
DAEN-ECE-D (Army), NAVFAC Code 04BA
structural systems are provided in Chapter 7.
(Navy), or HQ USAF/LEEE (Air Force).
Seismic Use Groups.
Examples of buildings or structures in each of the
above groups are provided in Table 4-1. Buildings
The following Seismic Use Groups are established
with multiple occupancies will be categorized
based on the occupancy or function of a building:
according to the most important occupancy, unless
the portion of the building that houses the most
Seismic Use Group IIIE
important occupancy can be shown to satisfy all of
buildings are those containing essential facilities that
the requirements for that occupancy.
are required for post-earthquake recovery, and/or
those structures housing mission-essential functions.
Mission-essential functions are those absolutely