海底岩溶隧道勘察、设计难度大，施工风险高。以大连市地铁5号线海底岩溶大直径盾构隧道为研究对象，首次采用“跨孔CT物探+钻探”的海底隧道岩溶勘察方案，通过有限元计算确定海底岩溶隧道加固范围，通过抗浮计算确定岩溶隧道基底加固标准，提出海底岩溶的海面预处理具体实施方案和盾构针对性设计方案，从而形成一整套海底岩溶盾构隧道勘察、设计及岩溶处理方案。

The exploration and design of tunnel in the submarine karst area are difficult and the construction risk is high. Hence, the crosshole CT geophysical prospecting + drilling method is adopted for the first time in largediameter submarine karst shield tunnel on Dalian Metro Line 5. And then the reinforcement range of the tunnel is determined by finite element method; the reinforcement standard of karst tunnel foundation is determined by antifloating calculation; and a specific implementation scheme of submarine karst pretreatment and the specific design scheme of shield construction are put forward. In this way, a whole set of exploration, design and treatment scheme of submarine karst shield tunnel is formed.