Analytical Method for Determining Bearing Capacity of Shallow Foundations on Unsaturated Soils
Publication: International Journal of Geomechanics
Volume 22, Issue 11
Abstract
The bearing capacity of foundations constructed on unsaturated soils depends on the soil saturation degree and thus the soil suction. This paper presents a simple limit equilibrium approach to compute the foundation bearing capacity on unsaturated soil using lateral earth pressure theory. An imaginary retaining wall is assumed to pass the edge of the foundation and active and passive lateral pressures on both sides of the wall are computed using the distribution introduced in an earlier study. Equating total active and passive thrusts on two sides of the wall gives the footing bearing capacity. The soil–water characteristic curve is used to obtain soil suction corresponding to different moisture contents and drained shear–strength parameters are used to determine the foundation bearing capacity. The developed method is applicable to sands and c-φ unsaturated soils with varying saturation degrees. The predicted results have been compared with data from seven case studies reported in the literature and found a satisfactory agreement. Parametric studies have been conducted to investigate effects of foundation embedded depths, two-layer soils, various suction stresses, and ground slope changes on the footing ultimate bearing capacity. The results show that with increasing the soil suction, the footing bearing capacity increases significantly.
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Published In
International Journal of Geomechanics
Volume 22 • Issue 11 • November 2022
Copyright
© 2022 American Society of Civil Engineers.
History
Received: Sep 16, 2021
Accepted: Apr 28, 2022
Published online: Aug 26, 2022
Published in print: Nov 1, 2022
Discussion open until: Jan 26, 2023
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