Abstract In this study, Submerged Floating Tunnel (SFT)-mooring-train coupled dynamics is solved in the time domain to investigate their dynamic and hydro-elastic interactions under wave and earthquake excitations. The SFT is modeled by the rod-FE (finite element) theory, and it is connected to mooring lines through dummy-connection-mass and linear and rotational springs. A 3D rigid-multi-body dynamic model is developed for train dynamics that consists of seven rigid bodies. The tunnel-train interaction is taken into consideration based on the wheel-rail correspondence assumption and the simplified Kalker linear creep theory. The developed computer simulation program is validated through comparisons with commercial programs and published results when possible. In the case of earthquake-induced dynamics of the coupled system, the effects of soil conditions, tunnel length, mooring interval, seismic-wave propagation, and seaquake are investigated. The magnitudes of the SFT downward motions induced by the moving train are small compared with the motions induced by earthquakes. The earthquake causes transient SFT responses especially at their lowest wet natural frequencies while high-frequency motions are induced by seaquake effect. Structural damping and seismic propagation play an important role in dynamic responses. The interaction of the tunnel and moving train is also evaluated for various train speeds in terms of the derailment and offload factors and riding-comfort criterion. For the given SFT and train designs, the offload factor and riding-comfort criterion can slightly exceed their limits at certain earthquake conditions with the speed as high as 70 m/s, which can be adjusted by reducing train speed.

中文翻译：

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波浪和地震中 SFT-系泊-列车相互作用的时域耦合动力学模拟

摘要 在这项研究中，在时域中解决了水下浮动隧道 (SFT)-系泊-列车耦合动力学问题，以研究它们在波浪和地震激发下的动力和水弹性相互作用。SFT 由杆 FE（有限元）理论建模，它通过虚拟连接质量和线性和旋转弹簧连接到系泊绳索。为列车动力学开发了一个 3D 刚体-多体动力学模型，该模型由七个刚体组成。基于轮轨对应假设和简化的 Kalker 线性蠕变理论考虑了隧道-列车相互作用。在可能的情况下，通过与商业程序和公布的结果进行比较来验证开发的计算机模拟程序。在耦合系统的地震诱发动力学的情况下，研究了土壤条件、隧道长度、系泊间隔、地震波传播和地震的影响。与地震引起的运动相比，由移动列车引起的 SFT 向下运动的幅度较小。地震引起瞬态 SFT 响应，特别是在其最低湿自然频率下，而高频运动是由海震效应引起的。结构阻尼和地震传播在动力响应中起着重要作用。还根据脱轨和卸载因素以及乘坐舒适度标准对不同列车速度下隧道和行驶列车的相互作用进行了评估。对于给定的 SFT 和列车设计，卸载系数和乘坐舒适性标准在某些地震条件下可能会略微超过其极限，速度高达 70 m/s，