隧洞涌水危险性分析——以涌水量大小为主

Hazard Analysis of Tunnel Water Inrush with Emphasis on Inflow Magnitude

摘要: 隧洞涌水危险性并不只取决于涌水量绝对值，还受纵坡、洞径、洞段空间位置、支护与堵排措施、围岩类别、地质构造和施工方法共同控制。富水岩溶、断层破碎带、管道型富水构造和深埋高外水压力洞段中，即使涌水量相同，其致灾后果也可能明显不同，甚至演化为突水突泥。本文根据当前文献并结合深埋长距离输水隧洞的工程特点，建立“涌水量阈值–隧洞类型–地质条件–处置措施”综合划分思路，并提出施工期分区预报、TBM超前探测、反坡排水、注浆堵水、监测预警和应急管控建议。综述认为：单纯以全洞平均涌水量划分风险容易低估掌子面瞬时突涌水、断层导水和反坡排水失效风险；对于深埋长距离有压输水隧洞，应同时采用总涌水量Q、单位长度涌水量q、峰值增长率、外水压力、围岩稳定性和排水冗余度作为动态判据。

Abstract: The hazard of tunnel water inrush is not determined solely by the absolute inflow magnitude; it is also jointly governed by the longitudinal gradient, tunnel diameter, spatial position of the tunnel section, support and plugging-drainage measures, surrounding-rock class, geological structure, and construction method. In water-rich karst, fault fracture zones, pipe-type water-rich structures, and deep sections with high external water pressure, even with the same inflow, the disaster consequences may differ markedly, or even develop into water and mud inrush. The review is based on the available literature and the engineering characteristics of deep, long water-conveyance tunnels. A combined framework of “inflow thresholds, tunnel type, geological condition, and control measures” is proposed. Recommendations are also given for zoned prediction during construction, advance probing ahead of TBM excavation, counter-slope drainage, grouting and water blocking, monitoring and early warning, and emergency control. The analysis indicates that risk may be underestimated when only the average inflow of the whole tunnel is used, because transient water inrush at the face, water-conducting faults, and failures of counter-slope drainage can govern the consequences. For deep, long, pressure water-conveyance tunnels, total inflow Q, unit-length inflow q, peak growth rate, external water pressure, surrounding-rock stability, and drainage redundancy should be used together as dynamic criteria.