Extension law of thin bedrock fissure based on particle discrete element

Conducted fissure channel through thick aeolian sand is produced in the thin bedrock under the influence of mining,which easily causes the disaster of water inrush and sand inrush. In order to research the growing laws of water conducted fissure channel of thin bedrock,the thin bedrock model considering complex stress with granular discrete el- ement theory was established. The fracture developing laws in the transverse plane of thin bedrock based on prefabrica- ted crack length,overburden rock pressure and water and sediment two phase actions were analyzed. Through the re- search,it was found that granular discrete element theory could reflect the failure mechanism of thin bedrock well. Ex- tended fracture develops with the “Y” or “X” type which relates to overburden rock pressure and prefabricated crack length. By the study of four extended fracture development stages under different primary crack lengths,overburden rock pressures and water and sediment two phase actions,the failure curves was obtained and quantitative relationship between the effects of different conditions on the crack propagation in thin bedrock was analyzed.