海底隧道涌水量的预测及其应用

海底隧道深埋于海水以下，处于高水压富水区，涌水是海底隧道的最大威胁。涌水量预测是海底隧道防排水设计和施工措施制定的依据。采用理论分析方法，推导了均质围岩中海底隧道注浆圈外表面、衬砌外水压力及涌水量的理论解析公式，并分析了涌水量与各量值之间的关系。通过对地下水渗流场数学模型研究，采用等效连续介质模型用数值方法分析了隧道渗流场的分布，计算出海底隧道的每延米涌水量，并与理论解析解进行了对比分析。结果表明：海底隧道的涌水量不仅与围岩和注浆圈的渗透系数的比值关系密切，而且还与隧道的半径、远场水压力、注浆圈的半径有关；数值计算所得结果与理论解析公式计算得到的涌水量基本一致；为了确保海底隧道施工及运营的安全，应采取“以堵为主，限量排放”的治水方案。

Prediction and Application of Water Gush Yield into Subsea Tunels

Subsea tunnels are located deeply under sea with high groundwater pressure,so water gushing is the biggest threat to subsea tunnels.Prediction of the water gush yield is the basis of making waterproof,drainage plans and construction measures in subsea tunnels.Using theoretical analysis,the article formulates the water gush yield and the water pressure at outer surface of grouted ring and lining and analyzes the relationship between water gush yield and other parameters.Through the research of seepage field numerical model,equivalent continuum model and numerical method were used to analyze the distribution of tunnel seepage field and the water gush yield of subsea tunnels per linear meter,also make a comparison with the result of theoretical method.Research results indicate that the water gush yield is not only closed related to the coefficient between permeability of surrounding rock and that of the grouted ring,but also goes with the radius of surrounding rock and grouted ring,and external water pressure;the result of combined numerical analysis and that of theoretical deduction are consistent.The water control plan of "stop firstly,drain slightly" should be adopted for the safety of construction and operation.