Application of the Simplified Stiffness Method to Design of Reinforced Soil Walls
Publication: Journal of Geotechnical and Geoenvironmental Engineering
Volume 144, Issue 5
Abstract
In an earlier paper, the writers proposed modifications to the AASHTO simplified method to address shortcomings in the method and to improve reinforcement load predictions for walls under operational conditions. The new method is called the simplified stiffness method to emphasize the importance of reinforcement stiffness on reinforcement loads rather than strength as in the current AASHTO approach. The method provides a seamless transition for walls built with soil reinforcing elements ranging from inextensible steel to relatively extensible geosynthetics. The accuracy of the new approach is examined statistically and predicted loads are demonstrated to be more accurate than loads computed using the AASHTO simplified method and a log spiral limit equilibrium–based approach. The paper shows how the simplified stiffness method can be applied within a load and resistance factor design (LRFD) framework. To ensure that the reinforced soil zone remains within working stress conditions, a new limit state to address failure of the soil within the reinforced soil zone is introduced and applied within the LRFD framework. Step-by-step design examples for three different wall cases constructed with cohesionless backfill soils are provided in the Supplemental Data for the paper.
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Acknowledgments
The work reported in this paper was part of a pooled fund research program supported by grants from the Natural Sciences and Engineering Research Council (NSERC) of Canada, the Ministry of Transportation of Ontario, the Department of National Defence (Canada) and the following state departments of transportation in the USA: Alaska, Arizona, California, Colorado, Idaho, Minnesota, New York, North Dakota, Oregon, Utah, Washington, and Wyoming. The writers would also like to thank Dr. Dov Leshchinsky for providing the computer program used to perform the log spiral limit equilibrium calculations reported in the paper, and Ms. Kathryn Hamilton (Research Assistant at RMC), who contributed to the work by checking some of the calculations in this paper.
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Published In
Journal of Geotechnical and Geoenvironmental Engineering
Volume 144 • Issue 5 • May 2018
Copyright
©2018 American Society of Civil Engineers.
History
Received: Mar 27, 2017
Accepted: Nov 8, 2017
Published online: Mar 15, 2018
Published in print: May 1, 2018
Discussion open until: Aug 15, 2018
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