Investigating the effects of diverse cavity morphologies on the mechanism of tensile crack-induced collapse: A phase field method approach

Tensile crack-induced collapse is widely distributed in major mountainous areas of China, often result in sudden and catastrophic consequences due to the rapid movement of the falling bodies. To better understand the development of tensile crack-induced collapses, the phase field method, originally used for studying brittle fracturing, has been further applied in this research. Firstly, the application of the phase field method in modeling rock tensile failure is validated, demonstrating its effectiveness. The rationality of applying the phase field method for analyzing tensile crack-induced collapses has been thoroughly investigated, and solutions to address phase field disorder have been proposed. By incorporating heterogeneity features and implementing a prefabricated crack, both approaches can effectively address the issue of phase field disorder. However, the latter method aligns more closely with engineering practices. The present study provides a comprehensive investigation into the development of tensile crack-induced collapses with varying cavity morphologies. The corresponding change laws of tensile crack-induced collapses are systematically analyzed and summarized. Moreover, novel stability evaluation parameters, including reduction coefficients and safety points, are proposed and successfully applied in calculations. Our research on different cave morphologies has shown that the depth and shape of a cave, as well as the thickness and center of gravity of protruding rock masses, significantly influence the development process of tensile crack-induced collapse. This approach facilitates a comprehensive examination of the fracture process and yields valuable insights into the mechanics underlying tensile crack-induced collapses.