Study on the development of plastic zone based on strain expressed Mohr- Coulomb yield condition

At present, there is a lot of research for slope stability, the inherent reason of slope instability is geotechnical material will get plastic deformation under load. In this paper, Mohr-Coulomb yield condition is transformed strain expressed to stress expressed. Based on this, analysis the effects that geotechnical material parameters internal friction angle phi, cohesion c and Poisson's ratiovto Mohr-Coulomb yield condition and the development of soil plastic zone. In addition, using the strength reduction FEM simulating the change of plastic zone distribution caused by change of the geotechnical materials parameters. The results show that the internal friction angle phi, cohesion c are reducted, the plastic zone expand; Increasing the Poisson's ratio., narrowing the slope's plastic zone; Plastic zone's different distribution is caused by different material parameters affect the yield surface.