STUDY OF STRENGTH REDUCTION METHOD CONSIDERING MATERIAL DEFORMATION AND FAILURE CHARACTERISTICS

Based on post-peak progressive failure process of material,the slope and dam foundation asynchronous strength reduction method conforming to the geotechnical materials deformation and failure law is proposed.And the calculation method of asynchronous reduction ratio is given based on Mohr-Coulomb criterion.Meanwhile,considering the different dilatancy properties of rock mass with different stress states and plastic deformation,the user subroutine USDFLD is compiled using the field variable interface of ABAQUS program.Then the dilatancy angle will varies with the minimum principal stress and plastic shear strain.Finally,an example is analyzed.The results show that:(1) At the working state of hydropower station,the stress level of the potential sliding surface stress is enhanced significantly,and it changes the dilatancy characteristics of rock mass on sliding surface.The factors of safety of dam foundation are obviously different from those with associated and non-associated dilatancy angles.(2) The factor of safety decreases significantly with the increase in asynchronous reduction ratio.Therefore,only considering the geotechnical materials′ real deformation law and failure process can correctly represent the factors of safety of slope and dam foundation.The analysis can provide meaningful results for the optimization design and stability estimation of large scale slope and dam foundation engineering.