LFRD Calibration of Pullout Resistance Factors Using Survival Analysis for Soil Nails in North Texas
Publication: Journal of Infrastructure Systems
Volume 22, Issue 2
Abstract
Reliability-based analysis of the calibration of pullout resistance factors () for soil nails are presented in this paper. To conduct the calibration, a total of 47 verification tests conducted in cohesive soil within the Lyndon B. Johnson (LBJ) Express construction project in North Dallas Texas were collected. Three failure criteria, i.e., creep test data, test curve evaluation, and load-elongation curve were selected to estimate the nominal bond resistance between soil and grout. As a result, 25 tests met at least one of the failure criteria. In addition, 45 existing test results from the National Cooperative Highway Research Program (NCHRP) Report 701 in cohesive soil were incorporated to the test database and resulted in a total of 92 soil nail tests including 22 nonfailed tests. These 92 tests were separated into three databases for analysis and calibration purposes. Statistical analysis was conducted on these databases to evaluate the predicted () to measured () nominal bond resistances and normal and lognormal distributions were conservatively fitted to the lower tail of the failed test data. A new survival analysis approach was proposed to analyze the resistance distribution, which allows for incorporation of the nonfailed verification testing results. Utilizing these distributions, calibration of was conducted by load and resistance factor design (LRFD) reliability analysis with the strength limit state and Monte Carlo simulations. A target reliability index () of 2.33 and load factors () of 1.0, 1.35, 1.5, 1.6, and 1.75 were selected for the calibration as a result of the redundancy and loading conditions commonly found in soil nail walls (SNWs). From this analysis, values were calibrated and ranged from 0.42 to 1.49, allowing engineers to select a value appropriate to the SNW characterizations and conditions in cohesive soil.
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Acknowledgments
The authors gratefully acknowledge the support and information provided by Trinity Infrastructure LLC and Craig Olden. In particular, the authors would like to thank Carlos Fernández Lillo, Cynthia Zuñiga, Carmen Díaz-Caneja, and Dr. D. L. Hawkins for their guidance throughout this research project. The comments and suggestions from reviewers are also greatly appreciated.
References
AASHTO. (2007). LRFD bridge design specifications, 4th Ed., Washington, DC.
Allen, T. M., Nowak, A., and Barthurst, R. (2005). “Calibration to determine load and resistance factors for geotechnical and structural design.”, Transportation Research Board, Washington, DC.
Baecher, G. B., and Christian, J. T. (2003). Reliability and statistics in geotechnical engineering, Wiley, New York.
Byne, R. J., Cotton, D., Porterfield, J., Wolschlag, C., and Ueblacker, G. (1998). “Manual for design and construction monitoring of soil nail walls.”, Federal Highway Administration, Washington, DC.
Elias, V., and Juran, I. (1991). “Soil nailing for stabilization of highway slopes and excavation.”, Federal Highway Administration, Washington, DC.
Hirary, A., and Kulhawy, F. H. (2002). “On the interpretation of drilled foundation load test results.” Deep Foundation 2002 (GSP 116), ASCE, Reston, VA, 1018–1028.
Kaplan, E. L., and Meier, P. (1958). “Nonparametric estimation from incomplete observations.” J. Am. Stat. Assoc., 53(282), 457–481.
Koutsoftas, D. C. (2000). “High capacity steel H-piles in Franciscan rock.” Proc., Geo-Denver, ASCE, Reston, VA, 157–177.
Lazarte, C. A. (2011). “Proposed specifications for LRFD soil-nailing design and construction.”, Transportation Research Board, Washington, DC.
Lazarte, C. A., Elias, V., Espinoza, R. D., and Sabatini, P. J. (2003). “Soil nail walls.”, Federal Highway Administration, Washington, DC.
Lee, E. T., and Wang, J. W. (2003). Statistical methods for survival data analysis, 3rd Ed., Wiley, Hoboken, NJ.
SAS 9.2 [Computer software]. SAS Institute, Cary, NC.
Withiam, J. L., et al. (1997). “Load and resistance factor design (LRFD) for highway bridge substructures.”, Federal Highway Administration, Washington, DC.
Yu, X., Murad, Y., Abu-Farsakh, M. Y., Yoon, S., Tsai, C., and Zhang, Z. (2012). “Implementation of LRFD of drilled shafts in Louisiana.” J. Infrastruct. Syst., 103–112.
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Information
Published In
Journal of Infrastructure Systems
Volume 22 • Issue 2 • June 2016
Copyright
© 2016 American Society of Civil Engineers.
History
Received: Nov 19, 2013
Accepted: Oct 23, 2015
Published online: Jan 20, 2016
Published in print: Jun 1, 2016
Discussion open until: Jun 20, 2016
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