双主动超前爆破预制顶板裂隙断顶卸压护巷技术

Roadway protection by roof breakage and pressure relief with dual-active blasting cracks prefabricated in roof

针对软岩巷道受采动应力长时间高压影响易发生围岩大变形的问题,以风水沟煤矿典型软岩矿井胶带巷为工程背景,采用现场调研、围岩应力及变形监测、数值模拟等手段,分析了软岩动压巷道围岩变形机制。从巷道顶板深部阻断应力传递路径、浅部高强支护角度出发,提出了软岩高应力巷道双主动超前断顶卸压+U型钢支架配合锚索高强支护协同控制技术。在5煤胶带巷未受工作面动压影响前,通过实施煤柱顶板深部长短孔爆破、浅部锚索高强支护方案,优化了巷道围岩应力环境,提高了围岩稳定性。基于围岩应力、电磁波CT、钻孔窥视、围岩位移等监测手段,开发了以保护巷道顶板浅部围岩、破坏深部围岩的综合成套监测技术体系,保证了双主动超前卸压护巷效果。

In terms of the problem of large deformation in soft rock roadway affected by long-term and high mining stress,the deformation mechanism of soft rock and dynamic pressurized roadway was analyzed by means of on-site investigation,surrounding rock stress and deformation monitoring,and numerical simulation,based on a case study located at the belt downhill of Fengshuigou Coal Mine of typical soft rock mines.From the perspective of blocking stress transmission path in deep roof and high-strength support in the shallow part of the roadway,the collaborative control technology for soft rock high-stress roadways was proposed,which consists of dual-active blasting cracks prefabricated in the roof and U-shaped steel support combined with anchor cable high-strength support.Before the belt downhill of 5th coal was not affected by the dynamic pressure of working face,the stress environment of the surrounding rock was optimized,and surrounding rock stability was improved,through the implementation of long-short holes blasting in the deep roof of coal pillar and high-strength anchor cable support in shallow.Based on monitoring methods such as surrounding rock stress,CT of electromagnetic wave,drilling peep,surrounding rock displacement,a comprehensive set of monitoring technology system has been developed to protect the shallow surrounding rock and destroy the deep surrounding rock of the roof of the roadway,ensuring the effect of protecting roadway by the dual-active advance pressure relief.