CEMP-E
TI 809-02
1 September 1999
b. Limited life structures. Limited life structures include both semi-permanent and
temporary construction as defined below.
(1) Semi-permanent construction will be designed and constructed to serve a life
expectancy of more than 5 years but less than 25-years (generally a 15-year service life), will
be energy efficient, and will include finishes, materials, and systems selected for a moderate
degree of maintenance using the life-cycle approach.
(2) Temporary construction will be designed and constructed to serve life
expectancy of 5 years or less, will use low cost construction, and systems selected with
maintenance factors being a secondary consideration.
1-12. STABILITY. The building foundation must be capable of safely transferring all vertical
and horizontal forces, due to specified design load combinations, to the supporting soil or rock.
The mechanism used for the transmission of horizontal forces may be friction between the
bottom of the footing and ground, friction between the floor slab and ground, and /or lateral
resistance of soil against vertical surfaces of grade beams, basement walls, footings, piles, or
pile caps. Net upward forces on footings and piles, which must be resisted to prevent
overturning and/or flotation, will be considered in the foundation design. Dead load should
include the benefits of weight of the overlying fill in resisting sliding, overturning, and flotation.
Structures will be designed to resist overturning effects caused by seismic forces in
accordance with TI 809-04. For load combinations other than earthquake when load
combinations applicable to allowable stress design (ASCE 7, paragraph 2.4.1) are used for the
foundation design, the building will have a minimum safety factor of 1.5 against sliding,
overturning, and flotation.
1-13. SPECIAL INSPECTIONS. Earthquake resistant structures designed in accordance with
TI 809-04 and FEMA 302 are required to undergo special inspections. The term "special
inspection" means that experts qualified in the installation, fabrication, erection or placement of
structural components and connections will be available on a periodic or continuous basis to
ensure the adequacy of the work. The type of special inspection depends on the type of
construction used (concrete, masonry, steel, etc.) and on the seismic region in which the
building is located. Special inspection requirements from FEMA 302 are addressed in the
various chapters of this report. The requirements in some cases have been generalized to
cover all types of loading conditions and combinations. Special inspections should not be
limited to those required by FEMA 302 and this document. Rather they should be specifically
required in the contract documents where ever they are needed to assure quality in
construction. It is the designers' responsibility to assure all special inspection requirements are
included in the contract specifications.
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