Supporting technology of roadway crossing fractured zone of fault under dynamic and static load

The gateway 5303 encountered multiple normal faults during the driving in Changping mine of Jinmei Group. For the purpose that the gateway can pass through the faults safely and rapidly and ensure applicative methods and scope of supporting. So based on the principle of maximum principal stress and fracture damage mechanics of rock, the paper analyzes the crushing mechanism of the normal fault zone under dynamic and static load from macroscopic and microscopic perspectives. Then, the plastic failure model of fault zone was established, the normal fault sliding mechanism and supporting theory were combined to derive the expression of the fault growth area and the domain of influence, and further analyzed by FLAC^3D. Research indicates that the rock will break when the sum of the maximum principal stress of the static and dynamic loads. Dynamic and static loads produce synergistic effect, mutative effect and common effect, which causes fracture zone damage and fractures in different ways microscopically, and the extent of which depends on the cosine and sine of the angle between the dynamic and static loads. The pre-grouting for increasing the strength of surrounding rock and the joint support methods that encrypt bolts and cables and single props with I-beams adopted to make the gateway 5303 pass through faults. According to theoretical calculations and numerical simulation results, the final pre-grouting and supporting range was determined to be 10 m before and after the fault zone.