海底隧道过风化槽防突水控制技术研究

Research on Control Techniques for Preventing Water Inrush in Submarine Tunnels Passing Through Weathering Troughs

海底隧道穿越风化槽一直是隧道施工的关键问题。风化槽岩体强度低,围岩自稳性差,软岩出露地质条件复杂,施工过程中易造成塌方、突水等地质灾害。以厦门海沧海底隧道工程为背景,采用数值模拟软件建立了隧道过风化槽数值计算模型,研究分析了注浆加固下对隧道位移场和渗流场的影响,得出注浆加固可减小隧道围岩失稳破坏,降低隧道过风化槽时发生突水灾害的概率。对此,提出了全断面帷幕注浆法,注浆时采用分区分段注浆及排水降压。现场实践表明:整个注浆效果良好,浆脉清晰,围岩得到有效加固,从而安全顺利地通过该风化槽段,没有发生突水等施工风险,相关经验值得借鉴。

Crossing weathering troughs in submarine tunnels has always been a key issue in tunnel construction.Due to the low strength of weathering trough rock mass,poor self stability of surrounding rock,and complex geological conditions of soft rock outcropping,geological disasters such as landslides and water inrush are prone to occur during construction.This paper takes the Xiamen Haicang Submarine Tunnel Project as the background,and uses numerical simulation software to establish a numerical calculation model of the tunnel passing through weathering troughs.The study analyzes the effect on the displacement and seepage fields of the tunnel under grouting reinforcement,and concludes that the grouting reinforcement can reduce the destabilizing damage of the tunnel surrounding rock and decrease the probability of water inrush disasters occurring when the tunnel passing through weathering troughs.In this regard,the full⁃section curtain grouting method is proposed,which uses zoned and segmented grouting and drainage pressure reduction during grouting.On⁃site practice has shown that the whole grouting effect is good,the slurry veins are clear,the surrounding rock is effectively reinforced,so as to safely and smoothly pass through the weathering trough section without any construction risks such as water inrush.The relevant experience is worth learning from.