Numerical Simulation of Overburden Failure in Gob Under Tectonic Stress

In order to study the laws of overburden failure in gob under tectonic stress, we used 06 working surface of the third lower coal seam of Shandong Xinhe Mining Company as the engineering background and studied the laws of overburden failure in gob in different tectonic stress fields with FLAC^3D numerical simulation and theoretical analysis methods. The results show that with the increase of side pressure coefficient, the range and the height of plastic zone of overburden in gob decrease first and then increase. The shape of the plastic zone of overburden in gob has experienced a process from the saddle to the pillow to the arch until finally changed to cap. The roof and floor of gob develops obvious stress decreasing area. With the increase of side pressure coefficient, the range of stress decreasing area expands along the roof, while the range of stress decreasing area gradually decreases along the floor. The range of tensile stress area in roof decreases and the range of stress concentration area in both sides of gob increases and the stress concentration phenomenon is enhanced. The range and the depth of floor rock failure in gob increase with the side pressure coefficient increasing.