Considering the Effect of Block-to-Matrix Strength Ratio on Geomechanical Parameters of Bimrocks

Abstract

The implementation of geomechanical projects is very challenging in rocks composed of rock blocks positioned in a weak matrix due to their complex structure. These types of rocks are called Block in matrix rocks or Bimrocks. Evaluating the geomechanical parameters of Bimrocks is significantly difficult. In this research, through fabricating large-scale physical samples, the effect of block size and volumetric block proportion (VBP) on compressive strength, deformation modulus, and velocity of S-wave and P-wave in Bimrocks were investigated. Using a 3D numerical simulation, the effect of variation in geomechanical parameters of matrix and rock blocks on strength and deformation modulus of the Bimrocks has been evaluated. The results show that the geomechanical parameters of rock blocks have a minor effect on the strength of Bimrocks; however, their effect becomes more when VBP is risen. The deformation modulus of Bimrocks is mostly affected by deformation modulus of matrix and the strength of Bimrocks is affected more by the cohesion of matrix.