Slope analysis based on local strength reduction method and variable-modulus elasto-plastic model
来源期刊：中南大学学报(英文版)2014年第5期
论文作者：YANG Guang-hua(杨光华) ZHONG Zhi-hui(钟志辉) FU Xu-dong(傅旭东) ZHANG Yu-cheng(张玉成) WEN Yong(温勇) ZHANG Ming-fei(张明飞)
文章页码：2041 - 2050
Key words：slope stability; local strength reduction method; variable-modulus elasto-plastic model; in-situ test
Abstract: Employing an ideal elasto-plastic model, the typically used strength reduction method reduced the strength of all soil elements of a slope. Therefore, this method was called the global strength reduction method (GSRM). However, the deformation field obtained by GSRM could not reflect the real deformation of a slope when the slope became unstable. For most slopes, failure occurs once the strength of some regional soil is sufficiently weakened; thus, the local strength reduction method (LSRM) was proposed to analyze slope stability. In contrast with GSRM, LSRM only reduces the strength of local soil, while the strength of other soil remains unchanged. Therefore, deformation by LSRM is more reasonable than that by GSRM. In addition, the accuracy of the slope’s deformation depends on the constitutive model to a large degree, and the variable-modulus elasto-plastic model was thus adopted. This constitutive model was an improvement of the Duncan–Chang model, which modified soil’s deformation modulus according to stress level, and it thus better reflected the plastic feature of soil. Most importantly, the parameters of the variable-modulus elasto-plastic model could be determined through in-situ tests, and parameters determination by plate loading test and pressuremeter test were introduced. Therefore, it is easy to put this model into practice. Finally, LSRM and the variable-modulus elasto-plastic model were used to analyze Egongdai ancient landslide. Safety factor, deformation field, and optimal reinforcement measures for Egongdai ancient landslide were obtained based on the proposed method.
YANG Guang-hua(杨光华)1, 2, 3, 4 , ZHONG Zhi-hui(钟志辉)1, FU Xu-dong(傅旭东)1, ZHANG Yu-cheng(张玉成)2, 3, WEN Yong(温勇)1, ZHANG Ming-fei(张明飞)4
(1. School of Civil and Architectural Engineering, Wuhan University, Wuhan 430072, China;
2. Guangdong Research Institute of Water Resources and Hydropower, Guangzhou 510610, China;
3. Geotechnical Engineering Technology Center of Guangdong Province, Guangzhou 510610, China;
4. School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510640, China)
Abstract:Employing an ideal elasto-plastic model, the typically used strength reduction method reduced the strength of all soil elements of a slope. Therefore, this method was called the global strength reduction method (GSRM). However, the deformation field obtained by GSRM could not reflect the real deformation of a slope when the slope became unstable. For most slopes, failure occurs once the strength of some regional soil is sufficiently weakened; thus, the local strength reduction method (LSRM) was proposed to analyze slope stability. In contrast with GSRM, LSRM only reduces the strength of local soil, while the strength of other soil remains unchanged. Therefore, deformation by LSRM is more reasonable than that by GSRM. In addition, the accuracy of the slope’s deformation depends on the constitutive model to a large degree, and the variable-modulus elasto-plastic model was thus adopted. This constitutive model was an improvement of the Duncan–Chang model, which modified soil’s deformation modulus according to stress level, and it thus better reflected the plastic feature of soil. Most importantly, the parameters of the variable-modulus elasto-plastic model could be determined through in-situ tests, and parameters determination by plate loading test and pressuremeter test were introduced. Therefore, it is easy to put this model into practice. Finally, LSRM and the variable-modulus elasto-plastic model were used to analyze Egongdai ancient landslide. Safety factor, deformation field, and optimal reinforcement measures for Egongdai ancient landslide were obtained based on the proposed method.
Key words:slope stability; local strength reduction method; variable-modulus elasto-plastic model; in-situ test
