摘要：High water pressure has always been the key problems in the construction and design of subsea tunnel. Relying on Xiang'an subsea tunnel,this paper made analysis of the application of reinforcement and water seal technology in the subsea tunnel passed through rich water sand stratum. High-pressure rotary jet grouting pile test, diaphragm wall and well-point dewatering project, advance strengthening test are studied. The result indicates that little or no water environment in the process of excavation and primary support is provided,with the appliance of diaphragm wall,surface well-point dewatering,pre-support with leading termite two-fluid(cement,water glass)grouting and grouting behind primary support at 50cm depth in rich water sand stratum. These research results have high referential value for analogous project.%针对海底隧道穿越潮间带富水砂层易发生涌砂、涌水地质灾害问题,开展现场试验研究.结果表明:潮间带富水砂层具有承压和潮汐动水特性；采用高压旋喷桩难以达到理想的堵水效果；钢板桩在含卵石的砾砂层施工中容易打偏,止水效果难以保证；在降水处理后,采用TSS管双液浆加固砂层效果明显.结合地质补勘资料,分析了翔安海底隧道及竖井在富水砂层地段发生险性事件的原因,提出在洞外采取地连墙和降水井对地下水进行控制,在洞内采用TSS管注浆预加固的技术方案穿越富水砂层,实践证明,可达到开挖和初期支护过程中基本无水和少水的效果,大大增强围岩自稳性,保证了施工安全,提高了施工进度.同时,还对富水砂层施工经验和不足进行总结与探讨,为今后类似工程建设提供参考和借鉴.