Bearing Capacity Analysis of Rock Mass Taking Account of Contact Interaction Along Discontinuous Lines

Abstract

A new stability analysis of rock mass is proposed by taking account of contact interaction along macroscopic discontinuous lines. The lower bound theorem in plasticity is employed with the finite element discretization technique. The joint element is introduced to describe the equilibrium equation in terms of stress in rock and contact traction along discontinuous line. The shearing behavior of joint as sliding and detachment is modeled as a rigid perfectly plastic one. The applicability of proposed method has been investigated in detail in comparison with the upper bound solutions by Tamura (1990). For every case, both computation results matched well indicating that both methods could be applicable to the stability estimation of a rock mass including macroscopic cracks inside. The ultimate bearing capacity of ground which includes discontinuous lines inside has been further assessed to investigate the effect of geometrical configuration and shearing property of discontinuous lines on the total stability. In particular, non-linear shearing property of discontinuous line against confining stress has been brought into the proposed method. The wide applicability of the proposed method to stability estimation of rock mass is clearly confirmed through some numerical studies.