倾斜煤层采动影响下的挤压变形区移动变形特征分析

The Movement and Deformation of Compression Area Under Mining in Inclined Coal Seam

以重庆南桐矿区为工程背景,通过三维数值模拟方法,对倾斜煤层在三种不同开采宽度工况下上覆岩层移动挤压变形区特征进行了研究。结果表明:采宽由80 m增加到160 m时,煤层与岩层交接处应力变化较小,挤压变形区地表下沉速度较为缓慢;采宽由160 m增加到240 m时,煤层与岩层交接处应力变化非常显著,挤压变形区地表产生明显下沉;不同的开采工况下,挤压变形区沉陷位移都会出现一个峰值,且位于开采区下山方向,挤压变形区沉陷值受水平应力影响较小,走向和倾向方向的沉陷值以该峰值曲线呈中心对称。

To understand the deformation pattern of the overlying strata under the conditions of three different mining widths(80,160,and 240 m),the Nantong mining area in Chongqing,SW China was selected,and three-dimensional numerical simulation was developed and conducted.Results show that when the mining width increased from 80 m to 160 m,the stress change at the joint of coal seam and rock stratum was small,and the surface subsidence in the extrusion deformation zone was relatively slow.When the mining width increased from 160 m to 240 m,the stress change at the joint of coal seam and rock stratum was very significant,and the surface of the extrusion deformation zone sank obviously.Under all the mining-width conditions,a peak value of subsidence displacement appeared in the extrusion deformation area,and was located in the downhill direction of the mining area.The horizontal stress had little influence on the subsidence in the extrusion deformation area,and the subsidence value in the strike and dip directions showed a symmetrical curve centered at the peak value.