急倾斜多煤层开采地表沉陷分区与围岩破坏机理——以木城涧煤矿大台井为例

Ground subsidence zone and surrounding rock failure mechanism due to steep multiple coal seam mining:a case study at Muchenyjian Datai Mine

为了研究急倾斜多煤层开采条件下地表及围岩移动变形特点,以木城涧煤矿大台井急倾斜多煤层开采为研究对象,进行了相似材料模拟研究.揭示了地表移动变形规律和围岩垮落、破坏机理,得出了不同区域移动变形的大小及主要特点,并与实地观测数据进行了对比分析.结果表明:该条件下开采,地表沉陷盆地可分为露头塌陷区、整体沉陷区、渐变沉陷区和轻微沉陷区,浅部开采形成的地表分区格局对整个采动影响区的地表移动变形起到了控制作用,浅部开采覆岩破坏以陷落和张裂为主要特征,深部开采以离层带裂隙顺层通达地表和台阶错落下沉为主要特征.

A similar material simulation was conducted to study the special characteristics of the ground displacement and the surrounding rock deformation caused by mining activities of steep inclined multiple coal seams,based on the conditions at Muchengjian Datai Mine.The pattern of ground displacement and the collapse mechanism of surrounding rock were identified.The magnitude and other features of the simulated ground displacement in different areas were presented and compared with field measurement data.The results show that the ground subsidence basin can be divided into four zones： outcrop collapse zone,main subsidence zone,gradual subsidence zone and mild subsidence zone.The ground partition pattern,especially caused by shallow coal seams exploration,can control the propagation of ground subsidence in the whole subsidence basin.The overburden strata will fall or crack as the main characteristics when they are affected by shallow coal seam exploration.Nevertheless,it will steeply sink or crack through separation layers to ground surface as the main features when they are affected by deep coal seam extraction.