上保护层开采双工作面卸压数值模拟

Numerical Simulation of Pressure Relief at Double Working Face in Upper Protective Layer Mining

为了研究上保护层双工作面开采后被保护层的卸压保护情况,结合祁南煤矿82采区上保护层顶底板岩层物理力学参数和地质特征,采用FLAC 3D软件模拟了上保护层双工作面6123与6125推进过程中应力场和变形场的演化特征,获得了被保护层7225与7227工作面最大主应力和变形随上保护层双工作面推进的变化特征;并根据《防突细则》中应力卸压与变形保护准则,确定其走向方向与倾斜方向的卸压范围.结果表明:上保护层6123与6125双工作面上(下)边界的卸压角分别为71.3°(77.4°)、75.8°(73.4°);沿走向方向的卸压角均为64.5°;数值模拟值与《防突细则》理论参考值基本一致,且均在实测的有效卸压范围内,采用数值模拟方法研究上保护层双工作面的卸压保护范围是可行的.

In order to study the pressure relief protection situation of protected layer after mining in double working face of the protective layer,combining with the physical and mechanical parameters and geological characteristics of the slate layer at the top and bottom of the upper protective layer in the 82 mining area of Qinan Coal Mine,this paper uses FLAC 3D software to simulate the evolution characteristics of the stress field and deformation field in the process of advancing the 6123 and 6125 double working faces of the upper protective layer,and obtains the maximum principal stress of the 7225 and 7227 working faces of the protected layer.According to the principle of stress relief and deformation protection in the outburst prevention regulation,the pressure relief range of the strike direction and incline direction is determined.Results show that the pressure relief angles of the upper(lower)boundary of 6123 and 6125 double working faces are 71.3°(77.4°)and 75.8°(73.4°)respectively,and the pressure relief angle along the strike direction is 64.5°;the theoretical reference values of the outburst prevention regulations are basically consistent with the numerical simulation values,and they are all within the effective pressure relief range of the actual measurement.So it is feasible to use numerical simulation method to study the pressure relief and protection of the double working faces of the upper protective layer,and the result is safe.