LRFD Calibration for Steel Strip Reinforced Soil Walls
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 138, Issue 8
Abstract
The paper reports the results of load and resistance factor design (LRFD) calibration for pullout and yield limit states for steel strip reinforced soil walls under self-weight loading. An important feature of the calibration method is the use of bias statistics to account for prediction accuracy of the underlying deterministic models for reinforcement load, pullout capacity and yield strength of the steel strips, and random variability in input parameters. To improve the accuracy of reinforcement load predictions, small adjustments to current semiempirical American Association of State Highway and Transportation Officials (AASHTO) load design charts are proposed. Similarly, current empirical-based design charts found in AASHTO and Federal Highway Administration (FHWA) guidance documents for the estimation of the pullout resistance factor for smooth and ribbed steel strips are adjusted to improve the accuracy of pullout capacity predictions. The results of calibration lead to a load factor of 1.35 that is consistent with current practice and resistance factors that together give a consistent probability of failure of 1% for all three limit states considered. Furthermore, comparison with allowable stress design (ASD) past practice (AASHTO simplified method) shows that the operational factors of safety using a rigorous LRFD approach give the same or higher factors of safety and lower probabilities of failure. In this study, data for steel strip reinforced soil walls are used as an example to illustrate rigorous reliability theory-based LRFD calibration concepts. However, the general approach is applicable to other reinforced soil wall technologies and calibration outcomes can be updated as more data become available.
Get full access to this article
View all available purchase options and get full access to this article.
References
Allen, T., Christopher, B., Elias, V., and De Maggio, J. (2001). “Development of the simplified method for internal stability.” Report WA-RD 513, Washington State Department of Transportation, Olympia, WA.
Allen, T. M. (2005). “Development of geotechnical resistance factors and downdrag load factors for LRFD foundation strength limit state design.” FHWA-NHI, 05-052, Federal Highway Administration, Washington, DC.
Allen, T. M., Bathurst, R. J., Holtz, R. D., Lee, W. F., and Walters, D. L. (2004). “A new working stress method for prediction of loads in steel reinforced soil walls.” J. Geotech. Geoenviron. Eng., 130(11), 1109–1120.JGGEFK
Allen, T. M., Nowak, A. S., and Bathurst, R. J. (2005). “Calibration to determine load and resistance factors for geotechnical and structural design.” Circular E-C079, Transportation Research Board, National Research Council, Washington, DC.
American Association of State Highway and Transportation Officials (AASHTO). (2002). Standard specifications for highway bridges, 17th Ed., Washington, DC.
American Association of State Highway and Transportation Officials (AASHTO). (2010). LRFD bridge design specifications, 5th Ed., Washington, DC.
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.” NCHRP Report 343, Transportation Research Board, National Research Council, Washington, DC.
Bathurst, R. J., Allen, T. M., and Nowak, A. S. (2008a). “Calibration concepts for load and resistance factor design (LRFD) of reinforced soil walls.” Can. Geotech. J.CGJOAH, 45(10), 1377–1392.
Bathurst, R. J., Huang, B., and Allen, T. M. (2011). “Load and resistance factor design (LRFD) calibration for steel grid reinforced soil walls.” Georisk, 5(3-4), 218–228.
Bathurst, R. J., Nernheim, A., and Allen, T. M. (2008b). “Comparison of measured and predicted loads using the Coherent Gravity Method for steel soil walls.” Ground Improv., 161(3), 113–120.
Bathurst, R. J., Nernheim, A., and Allen, T. M. (2009). “Predicted loads in steel reinforced soil walls using the AASHTO simplified method.” J. Geotech. Geoenviron. Eng., 135(2), 177–184.JGGEFK
Becker, D. E. (1996a). “Eighteenth canadian geotechnical colloquium: Limit states design for foundations. Part, I. An overview of the foundation design process.” Can. Geotech. J.CGJOAH, 33(6), 956–983.
Becker, D. E. (1996b). “Eighteenth canadian geotechnical colloquium: limit states design for foundations. Part II. Development for the National Building Code of Canada.” Can. Geotech. J.CGJOAH, 33(6), 984–1007.
Canadian Standards Association (CSA). (2006). “Canadian Highway Bridge Design Code (CHBDC).” CSA Standard S6-06, Canadian Standards Association, Toronto, Canada.
Christopher, B. R., et al. (1990). “Reinforced soil structures. Vol. 1: Design and construction guidelines.” Report FHWA-RD-89-043, Federal Highway Administration, Washington, DC.
D’Appolonia Engineering. (1999). “Developing new AASHTO LRFD specifications for retaining walls.” Report for NCHRP Project 20-7, Task 88, Transportation Research Board, Washington, DC.
Draper, N. R., and Smith, H. (1981). Applied regression analysis, 2nd Ed., John Wiley & Sons, New York.
Federal Highway Administration (FHWA). (2009). “Design and construction of mechanically stabilized earth walls and reinforced soil slopes—Vols. 1 and 2.” FHWA-NHI-10-024, Berg, R. R., Christopher, B. R., and Samtani, N. C., eds., Federal Highway Administration, Washington, DC.
Goble, G. (1999). “Geotechnical related development and implementation of load and resistance factor design (LRFD) methods.” Synthesis of Highway Practice 276, National Cooperative Highway Research Program, Transportation Research Board, Washington, DC.
Jones, C. J. F. P. (1985). Earth reinforcement and soil structures, ASCE, New York.
Kulhawy, F. H., and Phoon, K.-K. (2002). “Observations on geotechnical reliability-based design development in North America.” Proc., Int. Workshop on foundation design codes and soil investigation in view of international harmonization and performance based design, Honjo, Y., Kusakabe, O., Matsui, K., Kouda, M., and Pokharel, G., eds., Balkema, Lisse-Netherlands, 31–48.
Mitchell, J. K., and Schlosser, F. (1979). “Mechanics and behaviour—design methods: General Report.” Proc., Int. Conf. on Soil Reinforcement: Reinforced Earth and Other Techniques, Paris, 3, 25–62.
Nowak, A. S. (1999). “Calibration of LRFD bridge design code.” NCHRP Report 368, National Cooperative Highway Research Program, Transportation Research Board, Washington, DC.
Nowak, A. S., and Collins, K. R. (2000). Reliability of structures, McGraw Hill, New York.
Nowak, A. S., and Szerszen, M. (2003). “Calibration of design code for buildings (AC 318): Part 1–Statistical models for resistance.” ACI Struct. J., 100(3), 377–382.ASTJEG
Paikowsky, S. G. (2004). “Load and resistance factor design (LRFD) for deep foundations.” NCHRP Report 507, National Cooperative Highway Research Program, Transportation Research Board, Washington, DC.
Reinforced Earth Company (RECO). (1995). “Apparent coefficient of friction, f* to be used in the design of reinforced earth structures.” Technical Bulletin: MSE-6, Vienna, VA.
Schlosser, F. (1990). “Mechanically stabilized earth retaining structures in Europe.” Proc., ASCE Conf. on Design and Performance of Earth Retaining Structures, Cornell University, Ithaca, NY, 347–378.
Schlosser, F., and Elias, V. (1978). “Friction in reinforced earth.” Proc., ASCE Symp. on Earth Reinforcement, Pittsburgh, PA, 735–763.
Withiam, J. L., et al. (1998). “Load and resistance factor design (LRFD) for highway bridge substructures.” Report FHWA HI-98-032, Federal Highway Administration, Washington, DC.
Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 138 • Issue 8 • August 2012
Pages: 922 - 933
Copyright
© 2012. American Society of Civil Engineers.
History
Received: Aug 23, 2010
Accepted: Nov 15, 2011
Published online: Nov 17, 2011
Published in print: Aug 1, 2012
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.