Study On Near-Field Barrier Isolation Of Railway-Induced Vibration In Frozen Field

With the rapid development of the high-speed rail and heavy haulage, the environmental vibration and undesired noise induced by trains have an increasingly observable effect on the living of people, and it has become one of public nuisance. The environmental vibration and noise not only disturbs the living of people around the railway, but also influences the normal production and performance of precise instrument, and even destroy the ancient building. The frozen soil, whose destructiveness and disasters under train load are especially obvious, is extremely sensitive to the outside world. With the development of the railway scale in the frozen field, frozen soil will confront a bigger risk of destruction, so surely it is right to control the frozen field's vibration isolation. However, due to the Information at home and abroad, the research on the frozen field's vibration isolation is still a new subject. Based on the theories about transmission of the wave and finite-element's analytical method, the experiment and research outcomes about environmental vibration in the un-frozen field combines with the frozen field's dynamic characteristics in this dissertation. A vibration isolation's control method for frozen field is put forward. Meanwhile, based on the planar model, some factors, such as barrier's parameters, loads'character, train speed which influence the isolation effect, is analysed and summarized, and then, 3D model is established for inspection. Finally, the barrier's relevant parameters is optimized to obtain the best isolation effect.(1) This dissertation refers to some basic theories, includes the theories about the transmission and attenuation of the wave in elastic medium, the assessment of environmental vibration, the design criteria of the vibration isolation barrier and theories about the initiative vibration isolation in near field and the passive vibration isolation in far field.(2) Many problems about finite-element analysis of the environmental vibration in the frozen field are solved in this dissertation, the problems include confirm the parameters of frozen soil, the constitutive relation of the micro-strained soil, the dimensions of element, the whole model and timestep.(3) Make use of the areal model under the variational frequency harmonic loads to complete multi parameter analysis, then analyse the vibration isolation effect in different frequency band, and choose the best vibration isolation scheme finally. The final vibration isolation scheme in this dissertation is a combine of the continuous and discontinuous vibration isolation barrier. (4) Simulate and analyze vibration isolation effect of the 3D model which is about multiple temperatures frozen soil under variational frequency harmonic loads, and then validate the vibration isolation effect of the barrier.(5) Analyze and summarize the reduction of vertical acceleration and horizontal acceleration perpendicular to rail in the different temperature field. Meanwhile, the different running speed of train is considered in this part.