Gas migration control in goaf with double roof cutting and retaining roadway.

The behavior of gas migration in goaf under double roof cutting conditions directly influences the effectiveness of gas control measures. This study employs a combination of numerical simulation and field verification to investigate the patterns of gas migration and accumulation in goaf and to develop coordinated gas control methods under the conditions of double roof cutting and retained roadway. The results indicate that with double roof cutting, goaf permeability generally increases from the interior towards the exterior, with significantly higher porosity in the separation range compared to other areas.