摘要
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.
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.
基金
Project([2005]205)supported by the Science and Technology Planning Project of Water Resources Department of Guangdong Province,China
Project(2012-7)supported by Guangdong Bureau of Highway Administration,China
Project(2012210020203)supported by the Fundamental Research Funds for the Central Universities,China
