Research progress in roof cutting and pressure relief technology and its effect evaluation in deep coal mines

Existing studies on roof cutting and pressure relief mainly focus on their process parameters and engineering applications. However, they are limited in their whole-process coordinated evaluation on the appropriateness, controllability and sustainability of pressure relief, resulting in failure to timely identify insufficient or excessive pressure relief. This study therefore proposes a multi-source coordinated evaluation framework incorporating pre-cutting baseline identification, dynamic feedback during roof cutting, post-cutting effect verification and long-term stability tracking to enhance the effect evaluation of roof cutting and pressure relief. It characterizes the pressure-relief effect from point-scale stress, regional fracturing, stress redistribution and continuous deformation by summarizing the evaluation indicators of the drilling cutting method, microseismic monitoring, stress monitoring, and distributed fiber-optic monitoring. Results indicate that, instead of adopting site-independent absolute thresholds, the effect evaluation of roof cutting and pressure relief should take into account the relative changes of areas with and without, before and after roof cutting and the consistency of multi-source monitoring in spatial location, temporal evolution, and variation trends. The research findings can provide valuable reference for the study and engineering practice of roof cutting and pressure relief technology in deep coal mines.