Original scientific paper

The mechanism of inhibiting swelling deformation and slope instability of expansive soils by replacement method

Han Xu ; Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources, Changjiang River Scientific Research Institute, No. 23 Huangpu Road Wuhan, 430010, Hubei, P. R. China
Zhan-lin Cheng ; Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources, Changjiang River Scientific Research Institute, No. 23 Huangpu Road Wuhan, 430010, Hubei, P. R. China
Bin Huang ; Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources, Changjiang River Scientific Research Institute, No. 23 Huangpu Road Wuhan, 430010, Hubei, P. R. China
Jia-jun Pan ; Key Laboratory of Geotechnical Mechanics and Engineering of the Ministry of Water Resources, Changjiang River Scientific Research Institute, No. 23 Huangpu Road Wuhan, 430010, Hubei, P. R. China

Abstract

For expansive soils slope, replacement with non-swelling clay is always the most vital treatment measure. However, there are still many unsolved problems in the replacement method, including how to determine the optimal replacement thickness, and whether there was inhibition effect on slope instability of expansive soils. In this study, a "Stress Path Triaxial Testing System" (GDS) has been applied for exploring triaxial swelling rate. It proposed a triaxial swelling rate model for expansive soils, and this model was secondary developed and embedded in ABAQUS. Different thicknesses of replacement clay have been applied in treating slopes composed by strong, medium and weak expansive soil respectively. Sensitivity analysis also has been carried out with finite element method. For the strong expansive soil slope with natural moisture content 27,5 %, the safety coefficient without clay replacement was 0,73. The safety coefficient was 0,85; 1,08 and 1,33 with the replacement thickness of 1 m, 2 m and 3 m, respectively. The results validated that the replacement method could not only effectively inhibit the swelling of expansive soils, but also correspondingly improve the slope stability. In addition, the different replacement thicknesses could bring varied increasing rate of slope safety coefficient. The increasing rate was nonlinearly changed. Finally, it demonstrated the mechanical mechanism of inhibiting effects from existing replacement method on slope instability of expansive soils. The research results are able to provide theoretical basis for practical engineering. It could be conductive to treating swelling danger from expansive soil slope.

Keywords

replacement method; slope instability; swelling deformation; triaxial swelling rate model

Hrčak ID:

129055

URI

https://hrcak.srce.hr/129055

Publication date:

29.10.2014.

Article data in other languages: croatian

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