Study on Peak Shear Mechanical Properties of Structural Plane Under Relative Normal Force
The magnitude of the normal force has an important influence on the shear strength of the rock mass discontinuity,but there is no clear boundary for the division of the magnitude of the normal force.In view of this,the ratio of normal force to uniaxial compressive strength was formulated as a coefficient to measure the relative magnitude of normal force,and PFC2D was used to simulate shear experiments on structural planes with relative normal force under different roughness.The results show that the experimental results are basically consistent with the three-line shear strength theory.When the relative normal force is less than 0.06,the growth rate of shear strength is the highest,and the growth rate rapidly decreases with the increase of relative normal force.When the relative normal force is between 0.06-0.5,the decreasing trend of the shear strength growth rate becomes slower.When the relative normal force is greater than 0.5,the growth rate of shear strength is basically stable.Based on the three-line shear strength theory and the shear strength formula under medium normal stress,the cohesion strengthening index and climbing angle weakening index under shear action were obtained.By comparing the change trend of the two indexes under different materials,the rationality of the division of the upper and lower limits of the normal force was verified.
Normal forceShear strengthStructural planeParticle flowRoughness
万方数据
维普
