关键词: 富水隧道, 断层破碎带, 综合地质预报, 地表抽水试验, 分水降压, 预注浆

Abstract: The water and mud inrush are easily encountered during tunneling in fault and fractured zones with rich water. To address this issue, the hydrogeological parameters such as permeability coefficient of rock and soil and influence radius of pumping of fault F8 in Longnan Tunnel on JiangxiShenzhen Highspeed Railway are obtained by surface pumping test; the comprehensive prediction method of "geological radar + TSP + advanced drilling" is proposed to detect the fault affected area in advance; and comprehensive treatment measures such as water separation and pressure reduction, internal sealing and external consolidation, and safety monitoring are adopted. The results show that: (1) The permeability coefficient of rock and soil is 0.309 7~2.803 2 m/d, and the pumping influence radius is 247.59~763.31 m, which proves that the fault water in the tunnel has pressure bearing property, and provides the reference for the dewatering and drainage. (2) The comprehensive geological prediction is used to accurately detect the tunnel face DK99 +435, and the prediction results show that the face has entered the core area of fault F8 in advance. (3) The comprehensive treatment measures are adopted to control the discharge of fault water; the coring rate after grouting is 85%, and the water inflow is 0.83 L/(m·min), which indicates good grouting reinforcement effect.

Key words: waterrich tunnel, fault and fractured zone, comprehensive geological prediction, surface pumping test, water separation and pressure reduction, pregrouting