Research on Roof Cutting and Pressure Relief Technology of Deep Hole Pre-cracking Blasting

Abstract

The dynamic pressure gob-side entry is affected by the whole mining process of the working face, and the cause of the large deformation is the additional stress generated during the rotary sinking process of the key block. Therefore, in order to alleviate the deformation of surrounding rock of roadway along goaf. The deep hole pre-splitting blasting roof cutting pressure relief method is used to relieve the pressure of the test roadway. In this study, finite element and discrete element models were established by means of numerical simulation and theoretical analysis, and the law of influence of cutting top height and Angle on roof cutting effect is studied. The optimal cutting height and angle are 15 m and 10° towards the gob, respectively. The industrial test results show that the deformation of surrounding rock of the test roadway is controlled within a reasonable range after pressure relief, and the roadway section meets the production demand.