三软煤层回采巷道支护中钻孔卸压技术

为有效解决软岩巷道支护难题,提出并研究了钻孔卸压与U型钢联合支护方式。采用FLAC3D数值模拟软件分析了卸压钻孔对巷道围岩变形及应力转移作用机理,模拟结果表明,实施卸压钻孔后,巷道围岩的变形量减小,巷道周边围岩应力峰值向深部转移,巷道处于应力降低区。现场试验结果表明：采用钻孔卸压与U型钢联合支护方案,巷道两帮最大移近量193 mm,降低55%,巷道顶底板最大移近量267 mm,降低55%,巷道支护状况得到明显改善。

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 support method was provided and studied.The FLAC3Dnumerical simulation software was applied to study the function of the pressure releasing borehole to the surrounding rock deformation and stress migration mechanism of the mine roadway.The simulation results showed that after the pressure released borehole completed,the deformation 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 gateway 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 was 267 mm and was reduced by 55%.Thus the support conditions of the gateway were remarkably improved.