断层构造对北票矿区煤层气地表泄漏的影响

针对北票矿区台吉井田断层地质分布状况和关井后煤层气由地表泄漏的实际情况，从数值分析角度，利用ANSYS有限元软件，建立三维有限元模型，模拟了不考虑断层构造和考虑断层构造情况下，不同断层组合在开采前后的地应力场和位移场变化规律，得到了开采前后断层剖面应力场和特定水平剖面垂向位移等值线图等模拟结果，及一些有价值的结论。断层构造对开采前后应力场和位移场均有影响，应力场数值模拟得到采空区为原生气源集聚区；断层与采空区交界处的上、下端头位置所受应力最大，导致富集于采空区的煤层气向此处扩散运移，并通过断层中贯通裂隙向地表逸散，断层即是煤层气向地表逸散的重要通道；采空区上方的冒落带、裂隙带和弯曲带是次生气源集聚区。该数值模拟为搞清断层构造对北票矿区煤层气泄漏规律的影响和原生、次生气源集聚位置的确定提供了科学依据，对有效进行煤层气开发利用具有一定指导意义。

Effect of faults structure on surface gas leakage in Beipiao mining area

Based on the special faults structure condition of Beipiao mining area and the gas leakage situation after mines were closed, the three-dimensional finite element model was established using ANSYS software. The variation of stress field and displacement field were simulated under the condition of considering the effect of faults structure or not before and after mining. The contour charts of stress field in fault section and vertical displacements of special horizontal section etc. were presented. Some novel valuable conclusions were drawn based on the analysis and summary about rules of stress field and displacement field before and after mining. Those are that faults structure affects the laws of stress field and displacement field before and after mining; the gob is the original gas source concentration region; the maximal stress values exist in the top and lower ends of the adjacent between faults and gob. This leads to the gob gas diffusing to the adjacent region. Then gas leaks to the ground surface through the continuous fractures. So the faults are the important pathway of gas transport; caving region, fractures region and bending region are regarded as the secondary gas source concentration region. The numerical simulation supplies the scientific reference for faults structure effect on gas leakage, the region determination of the original and secondary gas source. The results have instruction rule for the utilization and usage of gas.