Bearing Capacity Analysis of Pile-Stabilized Slopes under Steady Unsaturated Flow Conditions
Publication: International Journal of Geomechanics
Volume 19, Issue 12
Abstract
When analyzing slopes stabilized by piles, the soil has been commonly considered dry or saturated, whereas soils are usually unsaturated in practice. Suction stress is caused by positive and negative pore water pressures, changing the strength properties of soils compared with soils without considering it and, consequently, leads to various stability conditions of a slope. In this study, a unified formula is presented for estimating soil-pile pressure in which the effect of suction stress is considered in variably saturated soils, which is an important extension of Ito and Matsui’s classical equation. Under such proposed formulation, an attempt has been made to develop a new method by means of the upper-bound limit analysis for analyzing the capacity of an unsaturated slope with vertical steady unsaturated flow reinforced by piles, and the most critical solutions for the optimal limiting surcharge are obtained by the optimization method. By comparing the results of the proposed method with other theoretical and experimental results in some examples, the method’s feasibility is verified. A numerical study for the parametric effects is also provided in this paper, which shows that the limiting surcharge is largely determined by soil properties, slope geometry, as well as seepage conditions. From an engineering application aspect, cost savings could be possible for the construction of slopes if a proper assessment of the effect of suction stress is completed.
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Acknowledgments
The authors would like to acknowledge the financial support from the National Science Foundation of China under Contract No. 51678230.
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Published In
International Journal of Geomechanics
Volume 19 • Issue 12 • December 2019
Copyright
©2019 American Society of Civil Engineers.
History
Received: Dec 13, 2018
Accepted: Apr 16, 2019
Published online: Oct 12, 2019
Published in print: Dec 1, 2019
Discussion open until: Mar 12, 2020
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