The Dynamic Response Analysis Of Shield Tunnel On Soft Soil Foundation Exposed To High-Speed Train Vibration Excitation

While the technology of high-speed railway gradually approaching mature under the circumstance of high-speed railway developing globally and soar development of high-speed railway construction in domain, the problem caused by vibration of railway communication became prominent. For serving economy growth by connecting the major cities located in Yangtze River delta, Pearl River delta and etc, railway tunnels frequently embedded in thick soft soil as saturated clay or unconsolidated sand. Exposed to train vibration excitation, pore pressure suddenly soar and dissipation delayed due to blocked drainage of surrounding clay, which finally lead to liquefaction and shear strength loss, tunnel subsidence, infected smoothly running and comfort of passenger even the safety of railway transportation.The analysis of this dissertation combined the train vibration and sand liquefaction. First, discussing mechanism of high-speed train vibration based on reviewing relevant subway research, artificially numbered excitation force is applied to the track simulated as unlimited Euler-Bernoulli beam to gain the reaction force of track supporting platform of ballastless track structure via calculation. Then this force is exerted to tunnel-ground model to calculated analysis. Combining dynamic consolidation theory of saturated soil and using Finn-Seed model, according to fluid-solid coupling situation of water-soil undergoing vibration induced by high-speed train, this dissertation respectively analyzedâ‘ dynamic response of shielded tunnel and the feature of ground stress and pore press distribution;â‘¡dynamic response of tunnel structure, variation of stress field and the stimulation and diffusion of pore pressure tolerating long-term cyclic high-speed train load.