Numerical Simulation of the Shear Mechanical Behavior of Rock Discontinuity During Direct Shear Test with Particle Flow Code

Abstract

In this paper, the shear mechanical behavior of rock discontinuity during direct shear test was studied by using Particle Flow Code. The feasibility of bond-debonding method and smooth-joint contact method to simulate the shear mechanical behavior of planar discontinuity was analyzed. The random distribution of particle size and position introduces some micro-roughness, which causes the non-actual stress concentration during the shear process using bond-debonding method. Particles on both sides of discontinuity are prone to cross the discontinuity during shearing, the unreasonable setting of contact type leads to non-actual stress concentration on the discontinuity with smooth-joint contact method. Therefore, it is proposed to adopt the discrimination method of contact and discontinuity intersection, and the discrimination method of particle groups on both sides of discontinuity, to overcome the disadvantages of smooth-joint contact method. Finally, through the direct shear test simulation of planer discontinuity with the friction angle of 57°under normal stress 3, 5, and 7 MPa, the feasibility of the discrimination method of particle groups on both sides of discontinuity was verified.

Keywords

• safety of rock engineering
• rock discontinuity
• shear mechanical behavior
• particle flow code