Importance of Lower-Bound Capacities in the Design of Deep Foundations
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 135, Issue 7
Abstract
There is generally a physical limit to the smallest possible capacity for a deep foundation. However, a lower bound on the capacity has rarely been accounted for in performing reliability analyses and developing reliability-based design codes. The objectives of this paper are to investigate the effect of having a lower-bound capacity on the reliability of a geotechnical engineering system and to propose a load and resistance factor design (LRFD) checking format that includes information on the lower-bound capacity in design. It is concluded that a lower-bound capacity can cause a significant increase in the calculated reliability for a geotechnical design even if it is an uncertain estimate. Two alternative LRFD formats that incorporate lower-bound capacities and that would not require substantive changes to existing codes are proposed. Real-world examples dealing with the design of onshore and offshore foundations indicate that the incorporation of a lower-bound capacity into design is expected to provide a more realistic quantification of reliability for decision-making purposes and therefore a more rational and efficient basis for design.
Formats available
You can view the full content in the following formats:
References
AASHTO. (1994). LRFD bridge and construction specifications, Washington, D.C.
AASHTO. (2004). LRFD bridge design specifications, Washington, D.C.
Aggarwal, R. K., Litton, R. W., Cornell, C. A., Tang, W. H., Chen, J. H., and Murff, J. D. (1996). “Development of pile foundation bias factors using observed behavior of platforms during hurricane Andrew.” Proc., Offshore Technology Conf., OTC 8078, Houston, 445–455.
Al-Awar, Z. (2002). “Developing a model for axial pile capacity in an offshore field.” Master’s thesis, Univ. of Texas at Austin, Austin, Tex.
American Petroleum Institute (API). (1993). API RP 2A-LRFD: Recommended practice for planning, designing and construction fixed offshore platforms—Load and resistance factor design, 1st Ed., Washington, D.C.
Ang, A. H.-S., and Tang, W. H. (1984). Probability concepts in engineering planning and design. Vol. II. Decisions, risk and reliability, Wiley, New York.
Barker, R. M., Duncan, J. M., Rojiani, K. B., Ooi, P. S. K., Tan, C. K., and Kim, S. G. (1991). “Load factor design criteria for highway structure foundations.” Final Rep. No. NCHRP Proj. 24-4, Virginia Polytechnic Institute and State Univ., Blacksburg, Va.
Bea, R. G., Jin, Z., Valle, C., and Ramos, R. (1999). “Evaluation of reliability of platform pile foundations.” J. Geotech. Geoenviron. Eng., 125(8), 696–704.
Doyle, E. H. (1999). “Pile installation performance for four TLP’s in the Gulf of Mexico.” Proc., 31st Offshore Technology Conf., OTC 10826, Houston.
Goble, G. G. (1996). “Load and resistance factor design of driven piles.” Transportation Research Record. 1546, Transportation Research Board, Washington, D.C., 88–93.
Goble, G. G. (1999). “Geotechnical related development and implementation of load and resistance factor design (LRFD) methods.” NCHRP synthesis of highway practice 275, TRB, Washington, D.C.
Hamilton, J. M., and Murff, J. D. (1992). “Selection of LRFD resistance factors for pile foundation design.” Proc., Structural Congress ’92, ASCE, San Antonio, 788–795.
Horsnell, M. R., and Toolan, F. E. (1996). “Risk of foundation failure of offshore jacket piles.” Proc., Offshore Technology Conf., OTC 7997, Houston, 381–392.
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, Hayama, Japan, 31–48.
Kuo, C. L., McVay, M. C., and Birgisson, B. (2002). “Calibration of load and resistance factor design.” Transportation Research Record. 1808, Transportation Research Board, Washington, D.C., 108–111.
Liang, R., and Nawari, N. O. (2000). “Evaluation of resistance factors for driven piles.” Geotechnical Special Publication No. 100, ASCE, New York, 178–191.
McVay, M. C., Birgisson, B., Nguygen, T., and Kuo, C. L. (2002). “Uncertainty in load and resistance factor design phi factors for driven prestressed concrete piles.” Transportation Research Record. 1808, Transportation Research Board, Washington, D.C., 99–107.
McVay, M. C., Birgisson, B., Zhang, L., Perez, A., and Putcha, S. (2000). “Load and resistance factor design (LRFD) for driven piles using dynamic methods—A Florida perspective.” Geotech. Test. J., 23(1), 55–66.
McVay, M. C., Ellis, R. D., Birgisson, B., Consolazio, G. R., Putcha, S., and Lee, S. M. (2003). “Load and resistance factor design, cost, and risk.” Transportation Research Record. 1849, Transportation Research Board, Washington, D.C. 98–106.
Najjar, S. S. (2005). “The importance of lower-bound capacities in geotechnical reliability assessments.” Dissertation, Univ. of Texas at Austin, Austin, Tex.
Olson, R. E., and Dennis, N. D. (1982). “Review & compilation of pile test results, axial pile capacity.” PRAC Project 81-29, American Petroleum Institute, Dallas.
Paikowsky, S. G. (2003). “Practical lessons learned from applying the reliability methods to LRFD for the analysis of deep foundations.” Proc., Int. Workshop on Limit State Design in Geotechnical Engineering Practice (LSD 2003), Mass.
Phoon, K. K., Kulhawy, F. H., and Grigoriu, M. D. (2003). “Development of a reliability-based design framework for transmission line structure foundations.” J. Geotech. Geoenviron. Eng., 129(9), 798–806.
Rodriguez, S. G. H., Henriques, C. C. D., Ellwanger, G. B., and de Lima, E. C. P. (1998). “Structural reliability with truncated probability distributions.” Proc., Int. Conf. on Offshore Mechanics and Arctic Engineering, OMAE, Lisbon, Portugal.
Simpson, B., Pappin, J. W., and Croft, D. D. (1981). “An approach to limit state calculations in geotechnics.” Ground Eng., 14(6), 21–28.
Tang, W. H. (1988). “Offshore axial pile design reliability.” Research Rep. to API, Phase I, PRAC Project No. 86-29B, Univ. of Illinois, Urbana-Champaign, Ill.
Tang, W. H. (1990). “Performance reliability of offshore piles.” Proc., Offshore Technology Conf., OTC 6379, Houston, 299–308.
Tang, W. H., and Gilbert, R. B. (1993). “Case study of offshore pile system reliability.” Proc., Offshore Technology Conf., OTC 7196, Houston, 677–686.
Withiam, J. L. (2003). “Implementation of the AASHTO LRFD bridge design specifications for substructure design.” Proc., Int. Workshop on Limit State Design in Geotechnical Engineering Practice (LSD 2003), Boston.
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 factor design (LRFD) for highway bridge substructures.” Rep. No. DTFH61-94-C-00098, FHwA, U.S. Department of Transportation, Washington, D.C.
Wu, T. H., Tang, W. H., Sangrey, D. A., and Baecher, G. B. (1989). “Reliability of offshore foundations—State of the art.” J. Geotech. Engrg., 115(2), 157–178.
Zhang, L., Tang, W. H., and Ng, W. W. (2001). “Reliability of axially loaded driven pile groups.” J. Geotech. Geoenviron. Eng., 127(12), 1051–1060.
Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 135 • Issue 7 • July 2009
Pages: 890 - 900
Copyright
© 2009 ASCE.
History
Received: Apr 3, 2008
Accepted: Nov 11, 2008
Published online: Feb 20, 2009
Published in print: Jul 2009
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.