Engineering Study On Isolation Of Propagation Of Vibration Induced By High-speed Trains Using Honeycomb Barrier

In recent years,high-speed railways have been developed rapidly in China. The oprations of high-speed railways in many foreign countries showed that the environmental vibration problems induced by high-speed strains including the vibration of the ground and the neighboring buildings are more serious when the strain's speed increases. These environmental vibrations would produce heavy influence on inhabitants'daily lives, work, manufacturing and application of certain precision instruments, and even to be a crisis to some ancient buildings.The barrier isolation (wave impeding barrier) is often applied to isolate or reduce the vibration in engineering practice. At present, the honeycomb wave impeding barrier (WIB) displays its positive advantages in the barrier isolation. In this paper, the FEM software ANSYS is used to model the barrier isolation of the honeycomb WIB. The results obtained from the analysis based on ANSYS present some valuable references to the vibration isolation in engineering practice. The main research contents in this paper are as follows:(1) The fundamental principle of the vibration propagation, the characteristics of the ground vibration propagation caused by the trains, the fundamental principle and standard of the ground barrier isolation, the active isolation of the vicinal vibration and the passive isolation of the faraway vibration and the level of vibration evaluating the isolation effects are introduced.(2) The FEM analysis of the honeycomb WIB system is carried out. In the analysis, the size of FEM model, the element size and the step time are discussed firstly. Secondly, the dynamic boundary conditions are expounded through the numerical analysis. And finally, the model size, the element size, the step time and the boundary conditions in the FEM analysis of the vibration isolation system are presented through the numerical examples(3) The plane strain model of FEM is established to analyze the honeycomb WIB system. The isolation effects of the honeycomb WIB with one row and two rows are investigated respectively when the packing material are set as soil-pile wall, cored-pile wall and tyre-pile wall and some valuable conclusions have been drawn.(4) 3-D FEM model including the embankment, the barrier and the ground is built to analyze the effects of the different distances of vibration source and the different lengthes of piles on the vibration isolation. These works are of theoretic and engineering values and present theoretic basis to engineering designs.