Roof fall mechanism and control method of roof with weak interlayer in mining roadway

In order to reveal the internal correlation between the weak interlayer position and roof fall of the mining roadway roof, comprehensive research methods including theoretical analysis, numerical simulation and field detection were adopted to study the surrounding rock fracture pattern and roof fall mechanism of mining roadway with weak interlayer roof, which leads to roadway roof fall in Nanshan Coal Mine mining roadway. The results show that the overall fracture shape of the roof of the roadway mainly depends on the thickness of the weak interlayer, the failure state and the physical and mechanical properties of the underlying hard rock layer. Under the influence of mining, the weak interlayer of roadway roof is easy to be damaged, accompanied by strong expansion deformation pressure, which may lead to the whole roof fracture. When the hard rock layer under the weak interlayer in the roof of Nanshan Coal Mine is less than 1.0 m, there will be the hidden danger of roof fall. Based on these results, the roof fall control of the mining roadway with weak interlayer roof is proposed to restrain the expansion of the weak interlayer fracture zone. The support design optimization and effect monitoring of return airway in Nanshan Coal Mine are carried out. The test results show that the support measures can effectively maintain the stability of roadway roof. © 2022, Editorial Board of Journal of CUMT. All right reserved.