Combining Snow and Earthquake Loads for Limit States Design
Publication: Journal of Structural Engineering
Volume 122, Issue 11
Abstract
ASCE Standard 7, “Minimum Design Loads for Buildings and Other Structures,” and the “NEHRP/BSSC Recommended Provisions for Seismic Regulations for Buildings” both contain load requirements for earthquake-resistant structural design. Many of the NEHRP provisions are being implemented in building codes and are the basis for the seismic load provisions in Chapter 9 of ASCE 7. However, the treatment of combinations of earthquake and snow loads differs in the ASCE 7 and NEHRP documents. Concerns regarding these differences were raised during the balloting of both the ASCE 7-93 and ASCE 7-95 provisions. To address these concerns, the load combination requirements involving dead, snow and earthquake load in these two resource documents were examined using modern probabilistic load models and load combination techniques. It is found that approximately 20% of the nominal snow load should be considered in combining snow and earthquake loads.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
Algermissen, S. T., et al. (1982). “Probabilistic estimates of maximum acceleration and velocity in rock in the contiguous United States.”Open File Rep. No. 82-1033, U.S. Geological Survey, Reston, Va.
2.
Brown, J. W.(1994). “Discussion of `Roof snow load for seismic design calculations' by O'Rourke and Speck.”J. Struct. Engrg., ASCE, 120(1), 309–312.
3.
“Building code requirements for reinforced concrete.” (1992). ACI 318-89, American Concrete Institute, Detroit, Mich.
4.
Cornell, C. A.(1968). “Engineering seismic risk analysis.”Bull. Seismological Soc. Am., 58(5), 1583–1606.
5.
Ellingwood, B., MacGregor, J. G., Galambos, T. V., and Cornell, C. A.(1982). “Probability based load criteria: Load factors and load combinations.”J. Struct. Engrg., ASCE, 108(5), 978–997.
6.
Ellingwood, B., and Redfield, R. K.(1983). “Ground snow loads for structural design.”J. Struct. Engrg., ASCE, 109(4), 950–964.
7.
Galambos, T. V., Ellingwood, B., MacGregor, J. G., and Cornell, C. A.(1982). “Probability based load criteria: assessment of current design practice.”J. Struct. Engrg., ASCE, 108(5), 959–977.
8.
Kanda, J.(1993). “Simplified load combination factors for snow load.”Struct. Safety, 13(1), 45–51.
9.
Load and resistance factor design specification for structural steel buildings (LRFD). (1993). American Institute of Steel Construction, Chicago, Ill.
10.
Melchers, R. E. (1987). “Structural reliability: analysis and prediction.” Ellis Harwood, Ltd., Chichester, U.K.
11.
“Minimum design loads for buildings and other structures.” (1995). ASCE 7-95 (previously ANSI Standard A58.1-1982), ASCE, New York, N.Y.
12.
“NEHRP recommended provisions for seismic resistant design of buildings.” (1992). FEMA Rep. No. 222, Federal Emergency Management Agency (FEMA), Washington, D.C.
13.
O'Rourke, M., Redfield, R., and Von Bradsky, P.(1982). “Roof snow loads.”J. Struct. Engrg., ASCE, 108(12), 2781–2798.
14.
O'Rourke, M., and Speck, R. (1992). “Roof snow loads for seismic design calculations.”J. Struct. Engrg., ASCE, 118(9), 2338– 2350.
15.
Reiter, L. (1990). Earthquake hazards analysis: issues and insights. Columbia University Press, New York, N.Y.
16.
Rubenstein, R. Y. (1981). Simulation and the Monte Carlo method. John Wiley, New York, N.Y.
17.
Turkstra, C. J., and Madsen, H.(1980). “Load combinations in codified structural design.”J. Struct. Engrg., ASCE, 106(12), 2527–2543.
18.
Uniform building code. (1993). International Conference of Building Officials, Whittier, Calif.
19.
Wen, Y. K.(1977). “Statistical combination of extreme loads.”J. Struct. Engrg., ASCE, 103(5), 1079–1095.
Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 122 • Issue 11 • November 1996
Pages: 1364 - 1368
Copyright
Copyright © 1996 American Society of Civil Engineers.
History
Published online: Nov 1, 1996
Published in print: Nov 1996
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.