UFC 4-023-03
25 January 2005
CHAPTER 1
INTRODUCTION
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PURPOSE AND SCOPE.
This Unified Facilities Criteria (UFC) provides the design requirements
necessary to reduce the potential of progressive collapse for new and existing DoD
facilities that experience localized structural damage through normally unforeseeable
events. This UFC incorporates a prudent, effective, and uniform level of resistance to
progressive collapse without expensive or radical changes to typical design practice.
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APPLICABILITY.
This UFC applies to new construction, major renovations, and leased
buildings and must be utilized in accordance with the applicability requirements of UFC
4-010-01 Minimum Antiterrorism Standards for Buildings or as directed by Service
Guidance. See Section 1-6 of UFC 4-010-01 for additional detail on the structures that
must be considered.
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GENERAL.
UFC 4-010-01 requires that all new and existing buildings of three stories or
more be designed to avoid progressive collapse. Progressive collapse is defined in the
commentary of the American Society of Civil Engineers Standard 7-02 Minimum Design
Loads for Buildings and Other Structures (ASCE 7-02) as "the spread of an initial local
failure from element to element, eventually resulting in the collapse of an entire
structure or a disproportionately large part of it." The standard further states that
buildings should be designed "to sustain local damage with the structural system as a
whole remaining stable and not being damaged to an extent disproportionate to the
original local damage." As discussed in the commentary of ASCE7-02, "except for
specially designed protective systems, it is usually impractical for a structure to be
designed to resist general collapse caused by severe abnormal loads acting directly on
a large portion of it. However, structures can be designed to limit the effects of local
collapse and to prevent or minimize progressive collapse." The structural design
requirements presented herein were developed to ensure prudent precautions are taken
when the event causing the initial local damage is undefined and the extent of the initial
damage is unknown.
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Significance of Progressive Collapse.
Progressive collapse is a relatively rare event, in the United States and other
Western nations, as it requires both an abnormal loading to initiate the local damage
spread of damage. However, significant casualties can result when collapse occurs.
This is illustrated by the April 19, 1995 bombing of the Alfred P. Murrah building in
Oklahoma City, in which the majority of the 168 fatalities were due to the partial collapse
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