海底隧道复合衬砌水压力分布规律及合理注浆加固圈参数研究

 与普通山岭隧道不同，海底隧道深埋于海床之下，地下水的处理是其修建过程中的关键问题，而隧道渗水量控制及衬砌结构水荷载确定又是地下水处理的核心问题。采用“堵水限排”的设计理念，设计海底隧道复合衬砌结构防排水系统，可以实现以较小的排放量明显折减甚至消除作用在支护结构上的外水压力，使海底隧道衬砌结构设计更经济。基于地下水水力学理论，推导海底隧道渗水量和复合衬砌结构外水压力的计算方法，并结合厦门海底隧道工程实践，采用理论分析和数值模拟方法揭示初期支护、二次衬砌以及注浆加固圈等参数的变化对隧道渗水量和衬砌外水压力的影响规律。在此基础上，提出海底隧道复合衬砌合理注浆加固圈参数的确定方法，并在厦门翔安海底隧道穿越F4风化深槽的合理注浆加固圈参数设计中取得成功应用。研究结果可为海底隧道或富水区高水头山岭隧道工程的防排水系统设计提供借鉴和参考。

STUDY OF DISTRIBUTION LAW OF WATER PRESSURE ACTING ON COMPOSITE LINING AND REASONABLE PARAMETERS OF GROUTING CIRCLE FOR SUBSEA TUNNEL

Different from land tunnels,the subsea tunnels are located deeply under the sea,so the groundwater treatment is the key issue during tunnel construction.Simultaneously,water inflow control and calculation of water load acting on lining structure are the core issues.The external water pressure on lining will be reduced remarkably with low discharge by adopting the design discipline of blocking groundwater and limiting discharge.So the design of lining structure in subsea tunnels is more economical.Based on the correlation theory of groundwater hydraulics,a calculation methods of water load acting on composite lining and water inflow in subsea tunnels is derived.Taking Xiang′an subsea tunnel in Xiamen for example,the influences of variable parameters of primary support,secondary support and grouting circle on water inflow and external water pressure are then expounded by using theoretical analysis and numerical simulation.Subsequently,the program and method for choosing economic and rational parameters of grouting circle are put forward;and the reasonable parameters of grouting circle for Xiang′an subsea tunnel through the weathered deep slot F4 are given,which gets satisfying effects.The results provide references for tunnel waterproofing and drainage system design in high water pressure and water-enriched regions including subsea regions.