Calibration of Resistance Factors for Load and Resistance Factor Design of Internal Limit States of Soil Nail Walls
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 145, Issue 1
Abstract
A general approach for calibration of resistance factors for load and resistance factor design (LRFD) of pullout and tensile failure internal limit states of soil nail walls is presented. The calibration of resistance factor values includes the influence of nominal load and nominal resistance model type and accuracy (method bias), bias dependencies, uncertainty in nominal load and resistance values, and possible cross-correlation (dependency) between nominal load and resistance terms. The current default Federal Highway Administration simplified method and an improved version are used to compute maximum nail loads under operational (in-service) conditions. Nail pullout capacity is calculated using the effective stress method adopted in Hong Kong and a more accurate modified version. Resistance factors are calibrated for a range of load factors and target reliability indexes. Example design outcomes for internal limit states of a soil nail wall using different load and resistance model combinations are presented. The benefit of using the more accurate improved load and resistance models for soil nail wall pullout design is demonstrated by a reduction in total length of soil nails.
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Acknowledgments
The authors are grateful for financial support through an ENGAGE research grant awarded to the corresponding author by the Natural Sciences and Engineering Research Council of Canada (NSERC).
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Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 145 • Issue 1 • January 2019
Copyright
©2018 American Society of Civil Engineers.
History
Received: Feb 15, 2018
Accepted: Jul 27, 2018
Published online: Nov 9, 2018
Published in print: Jan 1, 2019
Discussion open until: Apr 9, 2019
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