松散黄土堆积层下煤矿采空区地表塌陷形成机理

基于现场调查和室内测试，研究了青岛-兰州高速公路邯郸至涉县段沿线采空区地表塌陷特征，探讨了松散黄土堆积层下采空区地表塌陷的形成机理。研究结果表明：采空区地表塌陷表现为塌陷坑、地裂缝和沉陷盆地，分布规律不明显，塌陷明显滞后于煤层回采；地表塌陷形成的主要原因是由于煤层埋深浅，“两带”高度可直达地表，而上覆松散黄土层结构构造独特，具有一定的结构强度，因而不会立即垮落，在松散层内顺黄土垂直节理先形成拉裂缝，而后在地表水流作用下发生潜蚀、淘蚀，裂缝进一步扩大延伸而形成塌陷坑。

Formation Mechanism of the Ground Collapse in Mined-out Area of Coalmine Underlying Loose Loess Deposit

Based on field investigation and lab tests,the ground collapse characteristics of mined-out area along Qingdao-Lanzhou express highway has been studied.The formation mechanism of the ground collapse has been discussed further.The research shows that the ground collapse represents collapse hole,earth fissure and sinking basin,and the distributing rule is not good.The ground collapse is obviously hysteretic comparing with coal seam excavate.The main reason of ground collapse is that coal seams are buried low,and the two zones are through the earth's surface.Because the loose loess overlaying coal seam has unique structure and certain structural strength,it would not break down immediately.The tensile crack would form firstly along loess vertical joints in loose bed,and then the crack would develop corrosion and erosion under the condition of ground water current action,and the tensile crack would extend to form collapse hole finally.