NUMERICAL SIMULATION ON MECHANICAL RESPONSE OF ROCK MASS DUE TO TRAITS OF STRUCTURAL PLANE

This paper studies the influence that the properties of structural plane can make on the material properties of rock mass at Jinping site. A series of indoor triaxial compression tests are carried out. Based on the test results, four groups of numerical simulation tests for the influence that structural plane traits can make on rock mass mechanics properties are made out. Finally the instance of the slope excavation is numerically simulated. The indoor test results show that the rock failure process can be divided into four typical phases: elastic deformation stage, the yield stage, residual strength and plastic flow phase. As the confining pressure increases, the rock damage deviatoric stress increases gradually and shows the ductility properties gradually. Structural plane simulation results show that weak-filling structural planes have a larger degradation on rock mechanics properties than no-filling structure planes. The structure planes with a dip angle have larger degradation on rock mechanics properties than structure planes which the zero dip angle. Structure planes that have a larger dip angle have a larger influence on rock mechanics properties than the small dip angle's, and weak-filling thickness have a larger influence on internal friction angle of rock mass. Examples of simulation results show that excavation unloading causes the rebound deformation trailing edge of slope rock mass, and tensile displacements of X direction have developed in slope. Plastic zones extend along the lamprophyric vein which is a weak field. When the excavation is to 8 phase, lamprophyric vein is a plastic penetration area, which mean the slope is instable. The research results have certain guiding significance on excavation stability evaluation of high steep slope rock mass.