The Study On The Environmental Vibration Of High-speed Railway Cutting Area In Lanzhou Loess Area

With the rapid development of high-speed railway, although it has brought great convenience to people’s life, promote the development of the economy, but the environmental vibration caused by the problem can not be ignored. Especially has a wide distribution in loess area in our country, and the loess as a kind of porous structure, large pore, on water sensitivity of special soil, study the under repeated train loads caused by vibration problem is particularly important.In this paper, using the vehicle track coupling dynamics as the calculation theory, combined with the finite element method, the train track vertical coupling model is established, and the fastener loads acting on the track structure are obtained. Through the analysis of the fastener load under different speed, it can be known that the load is mainly concentrated in low frequency, with the increase of speed, the high frequency component of the fastener load increases gradually.Using ANSYS to establish double block ballastless track-cutting model. The fastener load as exciting force input into the model, analyzed the vibration response under different speed, and the acceleration peak value and the frequency spectrum amplitude increase with the increase of speed, and the high frequency component is also increased. Through the acceleration decay with distance from the cutting at the top of the analysis, we can see cutting depth increases within certain range will affect the cutting near the top of the ground vibration, but on the far-field ground vibration is very small.Comparative analysis of the propagation of different cutting depth on vibration effect. The peak acceleration and its spectrum amplitude reduces with the increase of cutting depth and the frequency range is also decreased. Through the acceleration with from the top of the cutting distance attenuation law analysis and shows the cutting depth increases in a certain range will affect the near the top of the cutting ground vibration, but on far-field ground vibration effect is very small.By comparing the effects of different cutting slope of the vibrational response, indicating that the peak acceleration and the spectrum amplitude decreases are cutting slope decreases slightly narrower frequency range. Through the acceleration decay with distance from the cutting at the top of the analysis, it was found in the cutting near the top of the range, the change will have an impact on the slope of the vibration acceleration attenuation slow down after, and basically had no impact on the more distant vibration.In this paper, the research object Lanzhou loess, loess different kinetic parameters of moisture content as a variable studied loess foundation vibration response. Vibration damping in loess rapidly, to a certain depth only low frequency components. Effect of water content on the acceleration of the trend was the opposite in the track structure and loess soils in the track structure, the acceleration increases as moisture content decreases. In loess foundation, the effect of water content on acceleration is small, with the increase of water content, the acceleration increases gradually.