NEHRP Clearinghouse

Title
Development of a Probability Based Load Criterion for American National Standard A58, Building Code Requirements for Minimum Design Loads in Buildings and Other Structures.
File
PB80196512.pdf
Author(s)
Ellingwood, B.; Galambos, T. V.; MacGregor, J. G.; Cornell, C. A.
Source
June 1980, 232 p.
Identifying Number(s)
NBS-SP-577
Abstract
Recommended load factors and load combinations are presented which are compatible with the loads recommended in the proposed 1980 version of American National Standard A58, Building Code Requirements for Minimum Design Loads in Buildings and Other Structures (ANSI A58.1-1980 D). The load effects considered are due to dead, occupancy live, snow, wind and earthquake loads. The load factors were developed using concepts of probabilistic limit states design which incorporate state-of-the-art load and resistance models and available statistical information. Reliabilities associated with representative structural members and elements designed according to current (1979) structural specifications were calculated for reinforced and prestressed concrete, structural steel, cold-formed steel, aluminum, masonry and glued-laminated timber construction. The report presents the rationale for selecting the criterion format and load factors and describes the methodology to be followed by material specification groups for determining resistance factors consistent with the implied level of reliability and the statistical data. The load factors are intended to apply to all types of structural materials used in building construction.
Keywords
Dynamic loads; Static loads; Probability density functions; Design; Specifications; Construction materials; UNIVAC-1108 computers; Aerodynamic loads; Computer programs; Fortran; Building codes