Deformation mechanism and stability control of roadway along a fault subjected to mining

It is difficult to maintain the roadway around a fault because of the fractured surroundings, complex stress environment, and large and intense deformation in the mining process. Based on a tailgate of panel S2205 in Tunliu colliery, in Shanxi province, China, we investigated the evolution of stress and displacement of rocks surrounding the roadway during the drivage and mining period using theoretical analysis, numerical simulation and field trial methods. We analyzed the deformation and failure mechanisms of the tailgate near a fault. The deformation of surrounding rock caused by unloading in the drivage period is large and asymmetric, the roadway convergence increases with activation of the fault and secondary fracture develops in the mining period. Therefore, we proposed a specific control technique of the roadway along a fault as follows: (1) High-strength yielding bolt not only supports the shallow rock to load-bearing structures, but also releases primary deformation energy by use of a pressure release device in order to achieve high resistance to the pressure retained; (2) Grouting of near-fault ribside after initial stabilization of the rock deformation is used to reinforce the broken rock, and to improve the integral load-bearing capacity of the roadway. The research results were successfully applied to a field trial.