Evaluation of unsaturated soil slope stability by incorporating soil-water characteristic curve

Loess soils are unsaturated and widely distributed in the northwest zone in China. Many steep slope of unsaturated are observed are observed to be naturally stable. However, a low factor of safety (FoS) for these slopes would be computed from the slope stability analysis following local code practic...

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Main Authors: Zhai, Qian, Tian, Gang, Ye, Weimin, Rahardjo, Harianto, Dai, Guoliang, Wang, Shijun
Other Authors: School of Civil and Environmental Engineering
Format: Journal Article
Language:English
Published: 2022
Subjects:
Online Access:https://hdl.handle.net/10356/163236
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author Zhai, Qian
Tian, Gang
Ye, Weimin
Rahardjo, Harianto
Dai, Guoliang
Wang, Shijun
author2 School of Civil and Environmental Engineering
author_facet School of Civil and Environmental Engineering
Zhai, Qian
Tian, Gang
Ye, Weimin
Rahardjo, Harianto
Dai, Guoliang
Wang, Shijun
author_sort Zhai, Qian
collection NTU
description Loess soils are unsaturated and widely distributed in the northwest zone in China. Many steep slope of unsaturated are observed are observed to be naturally stable. However, a low factor of safety (FoS) for these slopes would be computed from the slope stability analysis following local code practices. It seems that the analyzed results following the local code practices do not agree with the real condition as observed in the field. It is commonly known that soil suction plays an important role in slope stability due to a higher shear strength of the unsaturated soil as compared with that of the saturated soil. In this paper, it is observed that the computed FoS can also be affected by unsaturated unit weight of the soil. However, the effect of unsaturated unit weight of the soil on the slope stability is commonly ignored in engineering practice. Therefore, both the effects of shear strength and unit weight of the unsaturated soil on the computed FoS of unsaturated soil slope are investigated in this study. It is observed that the unsaturated unit weight of soil on the computed FoS increases with increase in slope angle. It is also observed that the effects of the unsaturated shear strength and unsaturated unit weight on the computed FoS are more significant than the effect of 3D analyses compared to the 2D analyses on the FoS.
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spelling ntu-10356/1632362022-11-29T05:50:06Z Evaluation of unsaturated soil slope stability by incorporating soil-water characteristic curve Zhai, Qian Tian, Gang Ye, Weimin Rahardjo, Harianto Dai, Guoliang Wang, Shijun School of Civil and Environmental Engineering Engineering::Civil engineering Shear Strength Slope Stability Loess soils are unsaturated and widely distributed in the northwest zone in China. Many steep slope of unsaturated are observed are observed to be naturally stable. However, a low factor of safety (FoS) for these slopes would be computed from the slope stability analysis following local code practices. It seems that the analyzed results following the local code practices do not agree with the real condition as observed in the field. It is commonly known that soil suction plays an important role in slope stability due to a higher shear strength of the unsaturated soil as compared with that of the saturated soil. In this paper, it is observed that the computed FoS can also be affected by unsaturated unit weight of the soil. However, the effect of unsaturated unit weight of the soil on the slope stability is commonly ignored in engineering practice. Therefore, both the effects of shear strength and unit weight of the unsaturated soil on the computed FoS of unsaturated soil slope are investigated in this study. It is observed that the unsaturated unit weight of soil on the computed FoS increases with increase in slope angle. It is also observed that the effects of the unsaturated shear strength and unsaturated unit weight on the computed FoS are more significant than the effect of 3D analyses compared to the 2D analyses on the FoS. The authors would like to acknowledge the financial supports he received from the National Natural Science Foundation of China (No. 42030714, 51878160, 52078128), China Huaneng Group Co. Ltd. (No. HNKJ19-H17), and the key laboratory of geotechnical and underground engineering (Tongji university) of Ministry of Education, (No. KLE-TJGE-B2003). 2022-11-29T05:50:06Z 2022-11-29T05:50:06Z 2022 Journal Article Zhai, Q., Tian, G., Ye, W., Rahardjo, H., Dai, G. & Wang, S. (2022). Evaluation of unsaturated soil slope stability by incorporating soil-water characteristic curve. Geomechanics and Engineering, 28(6), 637-644. https://dx.doi.org/10.12989/gae.2022.28.6.637 2005-307X https://hdl.handle.net/10356/163236 10.12989/gae.2022.28.6.637 2-s2.0-85127431745 6 28 637 644 en Geomechanics and Engineering © 2022 Techno-Press, Ltd. All rights reserved.
spellingShingle Engineering::Civil engineering
Shear Strength
Slope Stability
Zhai, Qian
Tian, Gang
Ye, Weimin
Rahardjo, Harianto
Dai, Guoliang
Wang, Shijun
Evaluation of unsaturated soil slope stability by incorporating soil-water characteristic curve
title Evaluation of unsaturated soil slope stability by incorporating soil-water characteristic curve
title_full Evaluation of unsaturated soil slope stability by incorporating soil-water characteristic curve
title_fullStr Evaluation of unsaturated soil slope stability by incorporating soil-water characteristic curve
title_full_unstemmed Evaluation of unsaturated soil slope stability by incorporating soil-water characteristic curve
title_short Evaluation of unsaturated soil slope stability by incorporating soil-water characteristic curve
title_sort evaluation of unsaturated soil slope stability by incorporating soil water characteristic curve
topic Engineering::Civil engineering
Shear Strength
Slope Stability
url https://hdl.handle.net/10356/163236
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