Destress blasting for strata separation near protective crosscut pillars – Case study

Protective crosscut pillars are solid sections of the rock mass that remain intact during underground coal mining. These pillars often experience a significant stress concentration, which can pose risk during mining activities nearby. The release of stress in the safety pillars could lead to uncontrolled rock bursting during active operations. To protect the progress of mining operations in the vicinity of the protection pillars of the southwest (SW) intersection between the 1st and 3rd mining blocks of the Lazy Colliery, special blasting operations are carried out, the purpose of which is to facilitate the isolation of the safety pillar area from the advancing longwalls area. This paper primarily aims to discuss the solution and the results of applying such a blasting approach in the area of the safety pillars of the SW crosscuts. Geomechanical and geophysical observations, combined with operational experience, were utilized in this study.