VARIABLE MODULUS ELASTOPLASTIC STRENGTH REDUCTION METHOD AND ITS APPLICATION TO SLOPE STABILITY ANALYSIS
YANG Guanghua1，2，ZHANG Yucheng1，2，3，ZHANG Youxiang2
(1. Guangdong Research Institute of Water Resources and Hydropower，Guangzhou，Guangdong 510610，China；2. School of Civil and Architectural Engineering，Wuhan University，Wuhan，Hubei 430072，China；3. China Construction the Third Engineering Bureau Co.，Ltd.，Wuhan，Hubei 430070，China)
Abstract：At present，only the strength parameters are reduced when the strength reduction method is used to analyze the slope stability；moreover，the ideal elastoplastic model is used. This method is mainly utilized to obtain the safety factor of slope stability. In elastic stage，it adopts the linear elastic model and elastic modulus is not reduced，so the nonlinearities of rock and soil are not considered fully before yielding. The deformation calculated by strength reduction method based on the ideal elastoplastic model is smaller. On the basis of the Duncan-Chang¢s model，variable modulus elastoplastic strength reduction method which reduces the elastic modulus in elastic state is proposed；and more practical deformation field can be obtained by this method. The variable modulus is obtained according to the simplified nonlinear constitutive model of soil. By comparing with the theoretical solution for strip foundation and the in-situ loading test results，the rationality of the new method is proved. The method is applied to the calculation of slope engineering deformation，and the relation between deformation and safety factor is hoped to be established to make the field deformation monitoring more reasonable. Meanwhile，it is easier to get the safety factor based on the deformation mutation calculated by the ideal elastoplastic model. It is proposed that the ideal elastoplastic model can be used to determine the safety factor，and the variable modulus elastoplastic model to calculate the deformation field.
