赣深高铁龙南隧道大型富水断层破碎带施工技术

为解决富水铁路隧道断层破碎带极易突水涌泥的难题,依托赣深高铁龙南隧道F8断层施工,采用地表抽水试验获取F8断层破碎带岩土体渗透系数、抽水影响半径等水文地质参数,提出“地质雷达+TSP+超前钻孔”综合预测手段超前探测断层影响区,并采用“分水降压+内堵外固+安全监测”等综合处理措施。结果表明： 1）通过地表抽水试验计算得出,渗透系数为0.309 7～2.803 2 m/d,抽水影响半径为247.59～763.31 m,验明隧道断层水具有承压性,为降排水提供依据; 2）运用综合地质预报精准探测隧道掌子面DK99+435已提前进入F8断层核心区; 3）采用综合处理措施,断层水可控排放,注浆后取芯率为85%,涌水量为0.83 L/(m·min),注浆加固效果良好。

Construction Technology of Large scaleWater rich Fault and FracturedZonein Longnan Tunnel on Jiangxi Shenzhen High speed Railway

The water and mud inrush are easily encountered duringtunneling in fault and fractured zones with rich water. To address this issue,the hydrogeological parameters such as permeability coefficient of rock andsoil and influence radius of pumping of fault F8 in Longnan Tunnel on Jiangxi ShenzhenHigh speed Railway are obtained by surface pumpingtest; the comprehensive prediction method of geological radar + TSP +advanced drilling is proposed to detect the fault affected area inadvance; and comprehensive treatment measures such as water separation andpressure reduction, internal sealing and external consolidation, and safetymonitoring are adopted. The results show that: (1) The permeability coefficientof rock and soil is 0.309 7~2.803 2 m/d, and the pumping influence radius is247.59~763.31 m, which proves that the fault water in the tunnel has pressurebearing property, and provides the reference for the dewatering and drainage.(2) The comprehensive geological prediction is used to accurately detect thetunnel face DK99 +435, and the prediction results show that the face hasentered the core area of fault F8 in advance. (3) The comprehensive treatmentmeasures are adopted to control the discharge of fault water; the coring rateafter grouting is 85%, and the water inflow is 0.83 L/(m·min), which indicates good grouting reinforcement effect.