Photo-elastic experimental and field measurement study of ground pressure of surrounding rock of large dip angle working coalface

Based on the large dip angle coal working face of WU 9-0-22090 of Xiangshan mine of Pingdingshan Coal and Electricity Co., Ltd., the ground pressure distribution laws of surrounding rock is studied through photo-elastic stimulation experiment and field measurement after coal mining. The research results show that the angle has an important effect on the distribution of the stress and bearing pressure of surrounding rock after coal mining, the deformation behavior, destroy characteristic and moving laws of stope roof of large dip angle coal working face are different with usual inclined working coal face; and the distribution of prop loading, the weighting presentation degree and the weighting distance are all different along the inclination of stope, and the distribution of roof stress is high nonuniform and asymmetrical. The roof stress is apparently concentrated in the two sides protected pillars' corner of goaf; then the bearing pressure region is formatted; and the pressure relieved region in the goaf of coal working face is also generated. The stress of stope roof relieved and the stress of two sides protected pillars are high concentrated; the shear stress of the four corners of stope apparently increased. And the shear strain mainly appeared in the roof of the low part of coalface and the floor of the upper part of coalface; the bulk strain is mainly focused in the adjacent coal roof and the two sides protected pillars. The research results are of significance in coal mining and roof management and enhancement of Xiangshan and similar coal mines.