Abstract
Abstract
The authors experimentally study initiation of tensile fractures from a circular cavity in a geomedium subjected to nonuniform compression. It is found that diameter of the cavity has a significant influence on the local fracture of the geomaterial. A new criterion is proposed for the quasi-brittle fracture of a material in the tensile stress concentration zone. The new criterion holds an integrated parameter which characterizes the size of the pre-fracture zone, the structure of a material and its plastic properties, the cavity geometry and the conditions of loading. The calculation and experiment result agree well.