基于颗粒离散元的薄基岩裂隙扩展规律#

Extension law of thin bedrock fissure based on particle discrete element

采动影响下的薄基岩产生导水裂隙通道,贯通厚风积沙层,容易产生突水溃沙灾害。为研究薄基岩导水裂隙通道发育规律,借助于颗粒离散元理论,建立考虑复杂应力作用的薄基岩模型,分析了原生裂隙长度、覆岩压力和水沙两相作用对裂隙在薄基岩平面横向发育规律的影响。研究发现颗粒离散元理论可以较好的揭示薄基岩的破坏机理;扩展裂隙在原生裂隙尖端呈"Y"和"X"型发育,且发育形态与薄基岩受到覆岩压力大小和原生裂隙长度有关。研究了不同原生裂隙长度、覆岩压力和水沙作用下裂隙扩展发育的4个阶段并给出了破坏曲线,分析了不同条件的改变对薄基岩裂隙扩展影响的定量关系。

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 element theory was established. The fracture developing laws in the transverse plane of thin bedrock based on prefabricated crack length,overburden rock pressure and water and sediment two phase actions were analyzed. Through the research,it was found that granular discrete element theory could reflect the failure mechanism of thin bedrock well. Extended 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.