复杂地质条件下巷道过断层关键技术研究及应用

Study and application of key technology for roadway crossing faults under complex geological conditions

断层破碎带具有低强度、易变形、透水性大和抗水性差的特征,巷道开挖常会引起断层活化,极易诱发巷道冒顶或突水事故。基于TSP、震波、瞬变电磁等综合物探超前地质预报技术与工程地质钻探,揭示了巷道掘进前方地层中的断层与含水特性,确立了巷道过断层的合理位置,为过断层巷道掘进施工、超前预加固与围岩支护设计提供了依据。采用地面与工作面预注浆等综合注浆技术,对断层破碎带区域岩体进行注浆堵水加固,形成了双层注浆堵水帷幕,有效地封堵了地下水,提高了巷道过断层区域围岩的完整性与强度,保证了巷道掘进过程中围岩的基本稳定与施工安全,并为后期巷道围岩锚固支护提供了可靠基础。针对断层破碎带岩性复杂、地质灾害突发等特征,基于综合物探预报结果与理论分析,提出了巷道合理掘进与支护技术方案;并针对后期承载和高抗渗性的要求,根据支护结构所承受的水压,采用合理的二次支护结构型式与防渗加固措施,保证巷道围岩与支护结构的长期稳定及安全。

The fault fracture zone characteristics of low strength, easy deformation, water permeability, and poor water resistance often lead to fault activation and induce the roadway roof fall or water inrush accidents during roadway excavation. Based on the comprehensive geophysical prospecting techniques of TSP, seismic wave and transient electromagnetic, the faults and the characteristics of water in road- way ahead in stratum were revealed, the reasonable position of roadway crossing faults was determined, which provided the basis for fault roadway excavation, pre-reinforcement and surrounding rock support design. The comprehensive measures of grounding and work face pre-grouting technology were adopted to reinforce the fault fracture zone through water blocking and rock grouting. During the process, a double-grouting plugging curtain was formed, the groundwater was blocked effectively, the integrity and intensity of the roadway surrounding rock in fault area were improved, the basic stability and con- struction safety of surrounding rock in roadway excavation were ensured, and the reliable foundation for later roadway surrounding rock anchor supporting was provided. According to the fault fracture zone characteristics of complex lithology and sudden geological disasters, reasonable roadway driving and supporting technical schemes were put forward based on theory analysis and comprehensive geophysi- cal prediction results. According to the requirements of load and high impermeability in later period, a reasonable type of secondary supporting structure and seepage-prevention reinforcement measures were taken to ensure the long-term stability and safety of the roadway surrounding rock based on the hydrau- lic pressure on the supporting structure.