叠加应力作用下急倾斜煤层区段防水煤柱留设研究

以急倾斜开采防水隔离煤柱留设为工程背景,采用理论分析和数值模拟作为主要手段,对急倾斜煤层上部覆岩运动规律进行了研究,认为煤层开采过后上覆岩层运动与水平煤层有较大差异,呈现岩层运动不对称垮落,煤柱裂隙发育度应该为左高右低,急倾斜煤层隔水煤柱上部塑性区宽度大于下部塑性区宽度,呈非对称分布。通过数值模拟得出,35 m保护煤柱下,上工作面裂隙发育高度大于下工作面,两工作面断裂拱发育不对称;煤柱中间区域位移量较小,可以满足生产要求;煤柱在上下两工作面作用下,压力峰值较高,达到18 MPa,上工作面靠近煤柱侧压力也较高,整个支承压力曲线呈现多个波峰波谷。

Study on the Design of Waterproof Coal Pillar in Steeply Inclined Coal Seam Under Superimposed Stress

In isolated coal pillar mining of waterproof engineering background of steeply inclined,theoretical analysis and numerical simulation are used as the main means to study the rules of steep coal seam rock movement upside.It is found that,after the coal mining,overburden movement and horizontal seam are different,showing asymmetric movement of strata collapse,coal column development degree should be left high and low on the right,upper water coal pillar width of the plastic zone is larger than the lower width of plastic zone and steep coal seam distribution is asymmetric.The numerical simulation shows that,under 35 m protective coal pillar,the fracture height of the upper working face is greater than that of the lower working face,and the fracture arch development of the two working faces is asymmetrical.The middle region of coal pillar has small displacement,which can meet the production requirements.Under the action of upper and lower working surfaces,the peak pressure of coal pillar is higher,reaching 18 MPa,the pressure on the upper working face near the coal pillar is also higher,and the whole bearing pressure curve presents multiple peaks and troughs.