巨厚松散层下大采高开采覆岩移动变形规律研究

Experimental study on movement and deformation of overburden rock in high cutting mining under extremely thick alluvium

为研究在巨厚松散层大采高条件下开采的地表移动变形规律和特点,以赵固二矿11050工作面地质采矿条件为背景,采用相似材料模拟实验方法来探讨地表沉陷过程中松散层和基岩两者的移动变形规律和下沉机理。研究表明:由于松散层具有强度低,承载能力差的特点,基岩在上部松散层巨大压力下显现出弯曲-离层-闭合的过程,基岩下部更易发生断裂以及破碎后被压实,增大了地表下沉;开采过程中地表动态移动变形较为剧烈,表现为地表点的动态移动变形在工作面推进一定距离后增加较快,其中最大下沉速度值为52.8mm/d、水平移动速度最大值为8.32mm/d。

To research surface movement deformation rules and characteristics in high cutting mining under extremely thick alluvium.Based on the geological background and mining conditions of 11050 working surface in Zhaogu No.2 Coal Mine,the similar simulation test was used to study the movement and deformation rules and subsidence mechanism of alluvium and bedrock in the process of surface subsidence.The result shows that： due to the low strength of alluvium,poor bearing capacity,bending-separating-closing process shows in the bedrock under tremendous pressure of upper unconsolidated layer,which increases the possibility for bedrock fracturing and compaction of broken rock in the lower part,thus intensifies the surface subsidence.Surface subsidence and deformation is intense during mining,surface dynamic subsidence and deformation increases rapidly after a certain distance of mining,the maximum subsidence velocity is52.8mm/d and maximum horizontal displace velocity is 8.32 mm/d.