Proactive intervention depressurization control for pre-mining roof fall and mining impacts

Aiming at the problem of surrounding rock control during the 52,102 working face passing through the roof fall area of return air roadway in lijiahao coal mine. Through on-site investigations, numerical simulations, and engineering practices, we analyzed the characteristics and causes of roof fall along the rib of the goaf. Based on the Mohr-Coulomb criterion, a numerical model was established, identifying influencing factors, and proposing an early intervention pressure relief control technology centered on "proactive avoidance." Determined the starting position and the staggered distance of the avoiding roadway. The study indicates that: (1) The deformation of the surrounding rock in the roof fall roadway is mainly affected by high static loads, mining pressure, mechanical properties of the surrounding rock, and the effect of pressure relief. The optimal timing for implementing the best prevention technology is to stop mining and excavate an avoidance roadway when the working face is 20 m away from the roof fall area. At the same time, based on safety and economic principles, determine the distance between the avoiding roadway and the original roadway is 20 m to shorten the length of the working face. After passing through the avoidance roadway, resume the use of the original roadway to ensure economic benefits. (2) Early proactive intervention pressure relief technology effectively reduces the deformation of the roadway surrounding rock, decreasing the amount of deformation on both sides by about 11%, verifying its effectiveness and practicality.