Numerical simulation study on deformation, failure and controlmechanism of high stress soft rock roadway

In view of the difficult problems of high stress soft rock roadway support, the high-stress soft rock roadway model under different supporting conditions was established by using discrete element numerical simulation method to study the high stress of the north wing transportation roadway of Kouzidong Coal Mine. The mechanism of deformation and failure of soft rock roadway and the support and reinforcement mechanism of different support methods for high stress soft rock roadway, and the technical measures for high stress soft rock roadway control were also investigated. The numerical result shows that the deformation and failure of the high-stress soft rock roadway in the Kouzidong Coal Mine was mainly concentrated on the roof and bottom of the roadway. In the floor, the sandy mud stone fails by means of opening and sliding along the bedding planes and gradually protrudes into the roadway to form an inverted V-shaped extruded floor heave. After the shallow immediate floor directly bulges, it provides a deformation space for the deep floor mud stone, which also begins to bend upward and deform. Under the action of high horizontal stress, the roof of the roadway expands and slides along the bedding plane and gradually protrudes into the roadway to form a V-shaped extrusion deformation failure. It is found that tensile failure plays a dominate role in the failure mode of the surrounding rock of the roof and floor. A support system consisting of rock bolts and cables, U-shaped yielding steel arches and back fill can successfully maintain the stability of roadway excavated in high-stressed soft rock due to its intrinsic feature of providing high support pressure after large deformations.