近海地层基岩起伏变化大，海底隧道线路必然在土层和岩层中穿行。地层不同隧道建设工法有别，衬砌结构类型也随之而变，工法交接段衔接结构也有差异。于是，在地下工程抗震方面带来两个难题：场地类别变化的土-岩交界区隧址的地震动特征；隧道衬砌结构刚度变化段地震响应机制。本项目拟以连续介质波动理论为基础，采用数值模拟方法研究土-岩交界区段的波动传播规律（反射、折射、散射）及其与地层特性的关系，分析归纳这类场地的地震动响应特征以揭示地层差异所致场地差动效应；以此为隧道基岩地震动输入条件，采用多尺度结构动力分析方法和结构振动台模型试验，研究海底隧道交接段典型结构型式（复合衬砌、装配式管片环、管片环复合内衬、复合衬砌套接管片环等）在多个地震水平（设防地震、罕遇地震、巨震）作用下的地震响应机制及强震破坏机理；在评价强震危害性的基础上，提出隧道交接段衬砌结构抗震与减震设计方法。

Heave rolling bedrock in coastal zone makes the routine of undersea tunnel fluctuate between soil and rock strata. The lining structure would vary to adapt to the construction in different strata, complicated lining of connection emerged when tunneling to transitional portion. Two issues to be considered in the earthquake engineering of underground construction: (1) the characteristics of near ground motion at tunnel location around transitional portion, and (2) seismic response of tunnel linings around connection zone. The proposed research will try to set up a numerical model to simulate the propagation of earthquake wave, and then summaries the characteristics of bedrock motion for the site to reveal the non-uniform excitation from geological condition. Analyze the seismic response of tunnel linings (such as composite lining, segmental lining, and the combination of both, etc.) under elevated earthquake intensity (such as fortified earthquake, rare earthquake, and huge earthquake) could be taken, by means of multiscale dynamic method and shaking-table tests based on the previous input of bedrock motion. The design methodology for the connection lining to withstand strong earthquake (both rare and huge one) can be developed with multiple measures.