The Research On The Model Test Of Not Continuous Reductions Of Vibration Isolation And Vibration Propagation In High-speed Railway Subgrade

High speed railway has many advantages,such as high efficiency,low load and low consume.It has been widely applied in the transportation industry,and has made great contributions to China's sustainable economic development.High speed railway will inevitably bring environmental problems about vibration and noise with the development of railway,the vibration problem is particularly prominent.How to improve the technology of high-speed railway development premise,It is the key to better reduce the environmental impact of vibration with the further development of high-speed railway.In order to study the influence of non continuous vibration reduction measures to reduce the effect of vibration isolation and the attenuation of the periodic structure domain characteristics.It analyzed the propagation of vibration wave in the soil and take the non continuous measures for vibration reduction of the size,arrangement form,spacing and row spacing into account through the indoor model test.It analysis non continuous vibration reduction measures(PVC wells,concrete piles,concrete profiled pile)the vibration reduction effect and its influence factors of reducing the effect of vibration isolation in order to clear the superiority of different frequency reducing the effect of vibration isolation.On this basis,it study of periodic piles,empty wells and the attenuation domain characteristics.The conclusion is as follows:(1)As the distance from the source increases,the acceleration of the soil surface decreases,and the high frequency vibration wave attenuates rapidly.With the increase of the distance from the measuring point,the acceleration attenuation is more intense,and then the acceleration attenuation tends to be gentle.(2)The closed PVC air well reduces vibration isolation effect well,and its vibration isolation effect increases with the increase of the diameter of the empty well.The depth of the buried well increases,and its vibration isolation effect increases.The spacing between the empty wells decreases,and its vibration isolation effect increases.(3)The concrete single pile the effect of vibration reduction is remarkable,its acceleration attenuation rate in 47.9%~70.5%,the section size of single row pile on the vibration reduction effect has no obvious effect;the buried depth of pile increased in order to increase the isolation effect;pile spacing decreases,the corresponding acceleration value decreases,the amplitude decreased less than that of concrete pile vibration reduction the vibration effect is more significant.(4)The order of reducing vibration isolation effect: the concrete piling?the heterosexual concrete pile?the PVC air well.The smaller the hollow ratio of the concrete shaped piles,the better the vibration isolation effect,but as the distance increases,the effect of the hollow rate on the vibration isolation effect is reduced to very small.With the change of the internal or external deformation of the profiled piles,the effect of vibration isolation is not changed,but the round is slightly better than the square;the effect that the profiled piles internal hollow is not filled with undisturbed soil than filled with undisturbed soil.(5)Periodic vibration isolation well has attenuation domain characteristics.The attenuation domain width increases with the number of rows,and the vibration isolation effect increases with the starting or stop frequency decrease.As well as we took the ratio range of geometrical parameters and wavelength in different row attenuation domain is obtained;The vibration isolation effect increases with decreasing attenuation domain width and starting or stop frequency and increasing vibration isolation well depth.Under the same diameter and spacing,the fill rate arrangement form larger can generate wider attenuation domain.At the same time we can also obtained that the ratio of filling rate and wavelength range under different arrangement form of attenuation.By increasing the vibration reducing well spacing and decreasing well diameter can improve the attenuation domain width.(6)Periodic vibration isolation piles has attenuation domain characteristics.The attenuation domain width increases with the number of rows,and the vibration isolation effect increases with the starting or stop frequency decrease.As well as we took the ratio range of geometrical parameters and wavelength in different row attenuation domain is obtained;The vibration isolation effect increases with decreasing attenuation domain width and starting or stop frequency and increasing vibration isolation pile depth.Under the same diameter and spacing,the fill rate arrangement form larger can generate wider attenuation domain.At the same time we can also obtained that the ratio of filling rate and wavelength range under different arrangement form of attenuation.By increasing the vibration reducing pile spacing and decreasing pile diameter can improve the attenuation domain width.