Assessment of Current Load Factors for Use in Geotechnical Load and Resistance Factor Design
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 129, Issue 4
Abstract
Load and resistance factor design (LRFD) is the standard structural design practice. In order for foundation design to be consistent with current structural design practice, the use of the same loads, load factors, and load combinations would be required. In this paper, we review the load factors presented in various LRFD codes from the United States, Canada, and Europe. A simple first-order second-moment (FOSM) reliability analysis is presented to determine appropriate ranges for the values of the load factors. These values are compared with those proposed in the codes. The comparisons between the analysis and the codes show that the values of load factors given in the codes generally fall within ranges consistent with the results of the FOSM analysis. However, it would be desirable for the successful development and adoption of the geotechnical component of LRFD codes to have uniformity of load-factor values across different codes for the loads that are common for virtually all civil structures.
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References
Allen, D. E.(1975). “Limit states design-probabilistic study.” Can. J. Civ. Eng., 2, 36–49.
American Association of State Highway and Transportation Officials (AASHTO). (1994). “LRFD bridge design specifications.” 1st Ed., AASHTO, Washington, D.C.
AASHTO. (1998). “LRFD bridge design specifications.” 2nd Ed., AASHTO, Washington, D.C.
American Concrete Institute (ACI). (1999). “Building code requirements for structural concrete (318-99) and commentary (318R-99).” ACI, Detroit.
American Institute of Steel Construction (AISC). (1994). “Load and resistance factor design specification for structural steel buildings.” 2nd Ed., AISC, Chicago.
American Petroleum Institute (API). (1993). “Recommended practice for planning, designing and constructing fixed offshore platforms — load and resistance factor design.” API, Washington, D.C.
Barker, R. M., Duncan, J. M., Rojiani, K. B., Ooi, P. S. K., Tan, C. K., and Kim, S. G. (1991). “Manuals for the design of bridge foundations.” Transportation Research Board, NCHRP Rep. No. 343, National Cooperative Highway Research Program, Washington, D.C.
Becker, D. E.(1996). “Eighteenth Canadian Geotechnical Colloquium: Limit States Design for Foundations. Part II. Development for the National Building Code of Canada.” Can. Geotech. J., 33, 984–1007.
Cornell, C. A. (1969). “Structural safety specifications based on second-moment reliability.” Symposium Int. Association Bridges and Structural Engineering, London.
Danish Geotechnical Institute (DGI). (1985). Code of practice for foundation engineering. DGI, Copenhagen, Denmark.
European Committee for Standardization (ECS). (1994). “Eurocode 7: Geotechnical design. I: General rules.” ECS, Central Secretariat, Brussels.
ECS. (1995). “Eurocode 1: Basis of design and actions on structures. I: Basis of design.” ECS, Central Secretariat, Brussels.
Ellingwood, B., Galambos, T. V., MacGregor, J. G., and Cornell, C. A. (1980). “Development of a probability based load criterion for American National Standard A58—Building code requirements for minimum design loads in buildings and other structures.” National Bureau of Standards, Washington, D.C.
Ellingwood, B. R., and Tekie, P. B.(1999). “Wind load statistics for probability-based structural design.” J. Struct. Eng., 125(4), 453–463.
Goble, G. (1999). “Geotechnical related development and implementation of load and resistance factor design (LRFD) methods.” Transportation Research Board, NCHRP synthesis 276.
Haldar, A. and Mahadevan, S. (2000). Probability, reliability, and statistical methods in engineering design, Wiley, New York.
Harr, M. E. (1987). Reliability based design in civil engineering, Dover, Mineola, N.Y.
Jaynes, E. T. (1957). “Information theory and statistical mechanics, II.” Phys. Rev., 108.
Lind, N. C.(1971). “Consistent partial safety factors.” J. Struct. Eng., 97(6), 1651–1669.
MacGregor, J. G.(1976). “Safety and limit states design for reinforced concrete.” Can. J. Civ. Eng., 3, 484–513.
MacGregor, J. G. (1997). Reinforced concrete mechanics and design, 3rd Ed., Prentice-Hall, Englewood Cliffs, N.J.
American Society of Civil Engineers (ASCE). (1996). “Minimum design loads for buildings and other structures.” ASCE 7-95, ASCE, Reston, Va.
Ministry of Transportation (MOT). (1992). “Ontario highway bridge design code.” MOT, Downsview, Ont., Canada.
Nowak, A. S.(1994). “Load model for bridge design code.” Can. J. Civ. Eng., 21, 36–49.
Nowak, A. S., and Grouni, H. N.(1994). “Calibration of the Ontario highway bridge design code 1991 edition.” Can. J. Civ. Eng., 21, 25–35.
National Research Council of Canada (NRC). (1995). “National building code of Canada.” NRC, Ottawa.
Withiam, J. L., Voytko, E. P., Barker, R. M., Duncan, J. M., Kelly, B. C., Musser, S. C., and Elias, V. (1997). “Load and resistance design (LRFD) for highway bridge substructures.” Federal Highway Administration, Washington, D.C.
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Copyright © 2003 American Society of Civil Engineers.
History
Received: Apr 26, 2001
Accepted: Jul 15, 2002
Published online: Mar 14, 2003
Published in print: Apr 2003
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