地面定向钻孔预注浆掩护巷道过断层带关键技术

Key Technology of Ground Directional Drilling and Pre-grouting Cover Roadway through Fault Zone

为解决巷道掘进过断层破碎带存在应力集中和围岩大量变形的情况,避免发生安全事故,以淮北矿区为例,提出了地面定向钻孔预注浆掩护巷道穿断层技术体系,完善了定向钻孔施工及地面高压注浆的关键技术,成功实施了四开成孔结构,有效避免了非治理段干扰。采用分段注浆法完成了破碎带的精准治理。通过压水试验、岩性探测、注浆量、浆液扩散距离、物探巷探验证、巷道支护效果等多方面对注浆效果进行了分析评价。结果表明:地面定向钻孔在巷道层位岩性的超前探查、高压预注浆等方面优势明显,有效提高了围岩的力学性质,减少了围岩的变形量,其中最大底鼓下降61.6%,保证巷道支护安全,可提高掘进效率,减少后期维护。

In order to solve the roadway drivage through fault fracture zone of stress concentration and large deformation of surrounding rock,and avoid accidents,taking Huaibei mining area as an example,put forward the technology system of ground directional drilling and pre-grouting cover roadway through fault zone perfected the directional drilling construction and the key technology of high pressure grouting on the ground,successful implementation of the four open pore structure,effectively avoid the governance section of interference.The segmented grouting method was used to complete the precise treatment of the broken zone.The grouting effect was analyzed and evaluated from many aspects,such as water pressure test,lithology detection,grouting amount,slurry diffusion distance,geophysical exploration verification and roadway support effect.The results show that the ground directional drilling has obvious advantages in advance exploration of lithology of roadway horizon and high pressure pre-grouting,which effectively improves the mechanical properties of surrounding rock and reduces the deformation of surrounding rock.The maximum floor heave is reduced by 61.6%,which ensures the safety of roadway support,improves the tunneling efficiency and reduces the late maintenance.