水下悬浮隧道锚索非线性动力特性及索与隧道动力耦合效应精细化研究

水下悬浮隧道(又称阿基米德桥)受跨度和水深的限制少，在海峡连接工程中有很大应用前景。其借助浮力悬浮于水中，一般采用缆索进行锚固实现稳定。索锚固的悬浮隧道在波流作用下的动力分析，需考虑多种非线性和动力耦合效应，包括索动力特性的非线性、索与隧道动力耦合及波流耦合效应。现有研究通过对上述效应的简化，建立了对悬浮隧道动力特性的一定认识。为推进悬浮隧道的实际应用，本项目对悬浮隧道中的非线性和动力耦合效应开展精细化研究：首先，研究能考虑锚索大垂度效应的建模及模型降阶方法，刻画锚索的非线性动力特性，通过模型实验进行对比研究；然后，研究面向大尺度、精细化分析的索与隧道静动力效应耦合的建模方法；最后，研究非线性波流耦合作用下悬浮隧道的结构响应机制。本项目将加深现有对波流作用下悬浮隧道及锚索非线性动力行为的认识；建立的模型和分析方法可直接用于未来的工程分析和设计，具有重要的科学价值和应用前景。

The Submerged Floating Tunnel (SFT, also known as the Archimedes bridge) is suitable for long-span crossing in deep water and hence is promising for strait crossings. The tunnel (or bridge) is floating in the water owing to the buoyancy effect and it often needs to be anchored to the seabed by mooring cables for its stability. Dynamic analysis of the SFT with mooring cables under waves and currents has to address several nonlinearities and interactions, including nonlinear cable dynamics, the coupled cable-tunnel-tube response, and the wave-current interaction. Existing studies have established some basic understanding of the SFT behaviors with simplification in dealing with those issues. To turn SFT into a reality in strait crossings, this project is therefore aimed to carry out dynamic analysis of the SFT and its cables with refined treatments of those difficulties. First, this project will study the nonlinear models of mooring cables able to consider large sag effects, develop model reduction techniques for mooring cables, and characterize nonlinear mooring cable dynamics, with comparison to cable model experiments; secondly, this project will develop a framework for coupling the cable-tunnel tube motions, on the basis of sub-structuring; lastly, the effects of nonlinear wave-current interactions on SFT responses will be examined. The outcome of this project will advance our understanding of the dynamic behaviors of mooring cables in SFTs and the joint effects of wave-current loads on SFT structural responses. The established mooring models and coupling schemes can be used for design and analysis in future engineering practice. In a word, this project is of both scientific and practical values.