The Subway Environment Vibration Research Based On The Theory Of The Cylinder

With the rapid development of subway, the problem of ground vibration induced by subway has received considerable attention. Corresponding subway vibration prediction and vibration reduction of environmental impact has become the focus of urban rail transit.On the basis of completely summing up previous research results, according to the actual situation of the urban subway in china, ground vibration induced by underground railway train is studied through theoretical and experimental analysis;propagation characteristics of vibration waves in the track-subgrade-ground system are systematically analyzed. The main contents include:1. In combination with the development of subway and the vibration problem,the research necessity of ground vibration due to underground train is described.Research status of environmental vibration of underground railway is summarized by classifying the method, and a number of issues requiring further study are put forwarded.2. The multi-layer cylinder method in which the modified dynamic flexibility matrix was proposed by Sheng is presented and developed. The moving dynamic flexibility matrixes of bottom of tunnel are specifically defined. The complete expressions of the Fourier transformed moving dynamic flexibility matrixes for elastic whole-space are derived and solved MATLAB programming problem. The reliabilities of the related theoretical analysis and programming are verified.3. According to different types of underground lines in Nanchang, tow of models such as the whole-slab track-tunnel-ground system model, the floating slab track-tunnel-ground system model are established. The matlab programming are finished. Analyzed the vibration isolation performance of floating slab track and by changing the steel spring floating slab bearing stiffness, the floating slab is obtained the relationship between the vibration damping performance. Dynamic responses of parts of the system generated by moving axle loads and track are analyzed;4. Considering harmonic irregularities, Vibration characters of layered groundand the track-subgrade –ground system in the subway lines in china are analyzed by means of the above analytical model.5. According to the track-subgrade –ground system analytical model, study the vibration characteristics of the rail- tunnel-ground system,the critical speeds of the system are emphatically studied. Dynamic responses of parts of the system generated by moving axle loads and track harmonic irregularities are analyzed.