Borehole Drilling and Pressure Releasing Technology Applied to Mining Gateway Support in Three Soft Seam

In order to effectively solve the support problems of the mine soft rock roadway, the borehole drill and pressure releasing and U type steel combined sup port method was provided and studied.The FLAC3Dnumerical simulation software was applied to study the function of the pressure releasing borehole to the surroundin g rock deformation and stress migration mechanism of the mine roadway.The simulation results showed that after the pressure released borehole completed, the defor mation value of the gateway surrounding rock was reduced, the stress peak of the surrounding rock along the gateway was moving forward to deep inside and the gate way was in the stress reduced area.The site test results showed that with the application of the borehole pressure released and U type steel combined support plan, the max convergence between the two sidewalls of the gateway was 193 mm and was reduced by 55%, the max convergence between the roof and floor of the gateway wa s 267 mm and was reduced by 55%.Thus the support conditions of the gateway were remarkably improved.