Research on evolution of integrated stress field of surrounding rock of mining while digging opposite roadway in deep and ultra-thick coal seam

Affected by high stress and multiple strong mining,the stress environment of the surrounding rock of mining while digging opposite roadway in deep ultra-thick coal seam is complicated and the roadway surrounding rock control is difficult; therefore,it is of vital significance for choosing roadway support methods and parameters to obtain the real stress evolution feature underground.Taking the auxiliary Transportation Lane 14103 of Majialiang Coal Mine as the engineering background,this paper revealed the evolution feature of in-situ stress field,mining induced stress field,support stress field and displacement filed of the roadway surrounding rock through underground onsite monitoring,theoretical analysis and numerical simulation.The distribution characteristics of the in-situ stress field of the roadway surrounding rock at Majialiang coal mine was obtained through the onsite monitoring; the onsite mining induced stress field monitoring showed that the lagging influence of the mining of the adjacent working face resulted in the main period of the mining induced stress increase; the pre-tightened bolts and cable bolts formed stable load bearing structure surrounding the roadway.Based on the comprehensive analysis of the stress field and displacement field evolution,it was concluded that the increase of the mining stress of the surrounding rock of the No.14103 auxiliary transportation lane occurred before the increase of the roadway deformation,the surrounding rock dilatancy and deformation happened due to the second mining stress influence,which resulted in the phenomenon of unobvious stress increase and significant deformation increase,and the temporal and spatial revolution and interrelation of the mining-induced stress field,support body stress and displacement field were revealed.The research outcomes provided the basis for choosing the roadway layout and support pattern.