永莲隧道大型承压含水体探查及处治方法研究

Exploration of Large Confined Aquifer of the Yonglian Tunnel and Relevant Treatment Measures

江西永莲隧道施工穿越断层破碎带时多次发生突水突泥灾害,严重影响隧道施工与运营安全。文章通过采用地球物理探测法与超前钻孔探查法确定承压不良地质含水体的空间位置、展布形态以及富水性等,并根据探测结果采取左洞重点涌水钻孔的小偏角原位扫孔注浆、含水体区域的左洞加密钻孔注浆、重点区段的帷幕加固圈加厚处理以及右洞工作洞室钻孔泄水释能并注浆的方法进行左右洞联合处治。注浆效果评价以及实际开挖效果表明,采用左右洞联合处治方法,承压含水体处治效果良好,含水体区域岩体的强度、稳定性及渗透性均得到了较大的提高,隧道顺利安全地通过了F2断层破碎带。

Water inflow and mud burst occurred frequently in the Yonglian tunnel passing through fault fracture zone,seriously affecting tunnel construction and operation safety. Geophysical prospecting and advanced drilling method were used to determine the spatial location,distribution pattern and water abundance of confined aquifer in unfavorable geology body. Based on the exploration results,relevant treatment measures for left and right tubes were conducted,such as in-situ hole cleaning and grouting of the key drill holes with water inflow in left tube,dense hole drilling and grouting of left tube in aquifer zone,thickening of grout curtain reinforcement circle of key sections,water drain and energy release by hole drilling and then grouting in working chamber of right tube. Evaluation of grouting effect and actual excavation result show that the treatment effect of confined aquifer is fine,the strength,stability and permeability of rock mass in aquifer area are significantly improved and the tunnel successfully passes through F2 fault fracture zone with the above mentioned method.