A PRELIMINARY STUDY FOR A COMPRESSION-SHEAR ROCK CRACK FRACTURE CRITERION BASED ON COULOMB-MOHR THEORY

摘要

The different criteria applications for opening propagation and shearing propagation for rock cracks are discussed. Two types of compression-shear fracture experiments for rock crack are conducted. The phenomena for rock crack fracture: firstly opening propagation and secondly shearing propagation under compression-shear loading condition arc realized. A shear fracture criterion is constructed based on Coulomb-Mohr strength criterion. The adoption of the characteristic scale r0 for the rock grain size used in the criteria is discussed. Experimental results are in good agreements with the values predicted by the shear fracture criteria.