Abstract
The intensive soil-water interaction in unsaturated expansive soil is one of the major reasons for slope failures. In this paper, the soil-water interaction is investigated with the full-scale field inspection of rainwater infiltration and comprehensive experiments, including wetting-induced softening tests, swelling, and shrinkage tests. It is demonstrated that the soil-water interaction induced by seasonal wetting-drying cycles is very complex, and it involves coupled effects among the changes in water content, suction, stress, deformation and shear strength. In addition, the abundant cracks in the expansive soil play an important role in the soil-water interaction. The cracks disintegrate the soil mass, and more importantly, provide easy pathways for rainfall infiltration. Infiltration of rainwater not only results in wetting-induced softening of the shallow unsaturated soil layers, but also leads to the increase of horizontal stress. The increase of horizontal stress may lead to a local passive failure. The seasonal wetting-drying cycles tend to result in a down-slope creeping of the shallow soil layer, which leads to progressive slope failure.
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References
Liu Tehong. Problems of Expansive Soils in Civil Engineering. Beijing: Architecture and Building Press of China, 1997 (in Chinese)
Bao Chenggang, Gong Biwei, Zhan Liangtong. Properties of unsaturated soils and slope stability for expansive soils. In: Proceedings of the 2nd International Conference on Unsaturated Soils. Beijing: International Academic Publishers, 1998, 2:71–98
Liao Jichuan. Engineering geological properties of expansive soils in cut slopes. In: Proceedings of Symposium on Theory and Practice of Unsaturated Soils. Beijing: Chinese Society of Civil Engineering, Division of Soil Mechanics and Foundation Engineering, 1992 (in Chinese)
Huang Shaojian, Ke Zhengjing, Fang Qiuyuan. Field monitoring of weather, suction, water content, and deformation in an expansive soil slope. In: Proceedings of Sino-Canada Symposium on Unsaturated Soils. Wuhan: Chinese Society of Civil Engineering, Division of Soil Mechanics and Foundation Engineering, 1994 (in Chinese)
Xu Yongfu. Mechanical properties of unsaturated expansive soils and its engineering application. Dissertation for the Doctoral Degree. Nanjing: Hehai University, 1997 (in Chinese)
Bao Chenggang. Stability of expansive soil slopes along the South-to-North water transfer canal and its stabilization methods. The people’s Yangtze River, 2003, 34(5): 4–7
Ng C W W, Zhan Liangtong, Bao Chenggang, et al. Performance of an unsaturated expansive soil slope subjected to artificial rainfall infiltration. Géotechnique, 2003, 53(2): 143–157
Zhan Liangtong, Ng C W W, Bao Chenggang et al. Field monitoring of an unsaturated expansive soil slope subjected to rainfall infiltration. Rock and Soil Mechanics, 2003, 24(2): 151–158 (in Chinese)
Zhan Liangtong. Field and laboratory study of an unsaturated expansive soil associated with rain-induced slope instability. Dissertation for the Doctoral Degree. Hong Kong: The Hong Kong University of Science and Technology, 2003
Fredlund D G, Rahardjo H. Soil Mechanics for Unsaturated Soil Mechanics. New York: Wiley Int, 1993
Take W A. Physical modeling of seasonal moisture cycles and progressive failure in embankments. Dissertation for the Doctoral Degree. Cambridge: University of Cambridge, 2003
Arad R, Konrad J M, Soulié M. Desiccation of a sensitive clay: Application of the model crack. Canadian Geotechnique, 1997, 34: 943–951
Richard B G, Peter P, Emerson W W. The effect of vegetation on the swelling and shrinkage of soils in Australia. Géotechnique, 1983, 33(2): 127–139
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Translated from Journal of Zhejiang University (Engineering Science), 2006, 40(3): 494–500 [译自: 浙江大学学报 (工学版)]
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Zhan, L. Soil-water interaction in unsaturated expansive soil slopes. Front. Archit. Civ. Eng. China 1, 198–204 (2007). https://doi.org/10.1007/s11709-007-0023-1
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DOI: https://doi.org/10.1007/s11709-007-0023-1