Reducing Uncertainty of Prediction from Empirical Correlations
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 130, Issue 5
Abstract
Empirical correlations with in situ or laboratory test results are routinely used in geotechnical designs and the uncertainty of prediction from these correlations can be substantial at times. This paper formalizes a procedure for characterizing and analyzing uncertainty in a design in which linear correlations have been used. In particular, how this design uncertainty can be reduced from gathering regional data and site-specific observations is addressed. The Bayesian approach is then applied to update empirical predictions with regional information or site-specific observations and hence to effectively reduce the uncertainty associated with the correlation. Three levels of uncertainty reduction associated with the use of an empirical correlation for design are discussed based on the availability of regional data and site-specific observations. Analyses of correlations for the shaft resistance of rock-socketed piles based on a global data set and a regional data set and for the shaft resistance of large-diameter bored piles in saporilitic soils based on site-specific observations are demonstrated as examples to implement the proposed procedure. In both examples, the uncertainty with the predictions updated by the proposed approach is significantly smaller than those directly associated with empirical correlations.
Get full access to this article
View all available purchase options and get full access to this article.
References
Ang, A. H.-S., and Tang, W. H. (1975). Probability concepts in engineering planning and design, 1, Wiley, New York.
Baecher, G. B., and Rackwitz, R.(1982). “Factors of safety and pile load tests.” Int. J. Numer. Analyt. Meth. Geomech., 6(4), 409–424.
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.
Christian, J. T., Ladd, C. C., and Baecher, G. B.(1994). “Reliability applied to slope stability analysis.” J. Geotech. Eng., 120(12), 2180–2207.
Duncan, J. M.(2000). “Factors of safety and reliability in geotechnical engineering.” J. Geotech. Geoenviron. Eng., 126(4), 307–316.
Evangelista, A., Pellegrino, A., and Viggiani, C. (1977). “Variability among piles of the same foundation.” Proc., 9th Int. Conf. on Soil Mechanics and Foundation Engineering, Tokyo, 493–500.
Fenton, G. A.(1999). “Estimation for stochastic soil models.” J. Geotech. Geoenviron. Eng., 125(6), 470–485.
Geotechnical Engineering Office (GEO). (1996). “Pile design and construction.” GEO Publication No. 1/96, Hong Kong.
Kay, J. N.(1976). “Safety factor evaluation for single piles in sand.” J. Geotech. Eng. Div., Am. Soc. Civ. Eng., 102(10), 1093–1108.
Kulhawy, F. H.(1996). “From Casagrande’s ‘calculated risk’ to reliability-based design in foundation engineering.” J. Boston Soc. Civ. Eng. Sect., Am. Soc. Civ. Eng., 11(2), 43–56.
Kulhawy, F. H., and Mayne, P. W. (1990). Manual on estimating soil properties for foundation design, Rep. No. EL-6800, Electric Power Research Institute, Palo Alto, Calif.
Lacasse, S., Guttormsen, T. R., and Goulois, A. (1990). “Bayesian updating of axial capacity of single pile.” Proc., 5th Int. Conf. on Structural Safety and Reliability, H.-S. Ang, M. Shinozuka, and G. I. Schuller, eds., ASCE, New York, 287–290.
Meyerhof, G. G.(1976). “Bearing capacity and settlement of pile foundations.” J. Geotech. Eng. Div., Am. Soc. Civ. Eng., 102(3), 195–228.
Ng, C. W. W., Yau, T. L. Y., Li, J. H. M., and Tang, W. H.(2001). “Side resistance of large diameter bored piles socketed into decomposed rocks.” J. Geotech. Geoenviron. Eng., 127(8), 658–669.
O’Neill, M. W. (1999). “Some effects of construction on the performance of deep foundations.” Analysis, design, construction, and testing of deep foundations, Geotech. Special Publication No. 88, ASCE, Reston, Va., 196–215.
Phoon, K. K., and Kulhawy, F. H.(1999). “Characterization of geotechnical variability.” Can. Geotech. J., 36(4), 612–624.
Ronald, E. W. (1982). Introduction to statistics, 3rd ed., Macmillan, New York.
Schmertmann, J. H. (1978). “Guidelines for cone penetration test, performance and design.” Rep. No. FHWA-TS-78-209, Federal Highway Administration, Washington, D.C.
Tang, W. H. (1972). “A Bayesian evaluation of information for foundation engineering design.” Statistics and probability in civil engineering, P. Lumb, ed., Hong Kong University Press, Hong Kong, 174–185.
Tang, W. H. (1984). “Principles of probabilistic characterizations of soil properties.” Probabilistic characterization of soil properties: Bridge between theory and practice, D. S. David and H.-Y. Ko, eds., ASCE, New York, 74–89.
Tang, W. H., Stark, T., and Angulo, M.(1999). “Reliability in back analysis of slope failures.” Soils Found., 39(5), 73–80.
Tang, W. H., Zhang, L. M., and Zhang, L. (2002). “Reliability-based design of large-diameter bored piles in Hong Kong—Part 2: Bayesian updating using load tests.” Proc., Int. Workshop on Foundation Design Codes and Soil Investigation in View of International Harmonization and Performance Based Design, Y. Honjo, O. Kusakabe, K. Matsui, M. Kouda, and G. Pokharel, eds., Balkema, Rotterdam, The Netherlands, 273–281.
Whitman, R. V.(2000). “Organizing and evaluating uncertainty in geotechnical engineering.” J. Geotech. Geoenviron. Eng., 126(7), 583–593.
Wu, T. H., Tang, W. H., Sangrey, D. A., and Baecher, G. B.(1989). “Reliability of offshore foundations—State of the art.” J. Geotech. Eng., 115(2), 157–178.
Yau, T. L. Y. (2000). “Capacity and failure criteria of bored piles in soils and rocks.” MPhilos thesis, The Hong Kong University of Science and Technology, Hong Kong.
Zhang, L. M., and Tang, W. H. (2002). “Use of load tests for reducing pile length.” Deep foundations 2002, Geotechnical Special Publication No. 116, ASCE, Reston, Va., 993–1005.
Zhang, L. M., Tang, W. H., and Zhang, L. (2002). “Reliability-based design of large-diameter bored piles in Hong Kong—Part 1: Evaluation of design methods.” Proc., Int. Workshop on Foundation Design Codes and Soil Investigation in View of International Harmonization and Performance Based Design, Y. Honjo, O. Kusakabe, K. Matsui, M. Kouda, and G. Pokharel, eds., Balkema, Rotterdam, The Netherlands, 263–271.
Information & Authors
Information
Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 130 • Issue 5 • May 2004
Pages: 526 - 534
Copyright
Copyright © 2004 American Society of Civil Engineers.
History
Received: Jan 10, 2003
Accepted: Jul 18, 2003
Published online: Apr 15, 2004
Published in print: May 2004
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.