Vibration isolation effect study of in-filled trench barriers to train-induced environmental vibrations: Fid-Bau Portal

Vibration isolation effect study of in-filled trench barriers to train-induced environmental vibrations

Yao, Jinbao / Zhao, Rutao / Zhang, Nan / Yang, Dujuan

Abstract An in-filled trench barrier is usually used to reduce the damages from train-induced environmental vibrations. To find the vibration isolation effect of an in-filled trench barrier, this paper analyses the reflection coefficients and transmission coefficients of the Rayleigh wave at the interface between in-filled trenches and the soil. In our calculation formulas of ground vibrations, a single point and a single frequency excitation, as well as multi-point and multi-frequency excitation, are simultaneously derived in a soil-in-filled-trench system. Using these formulas and a numerical analysis, the effects of an in-filled trench barrier on the environmental vibrations induced by running trains are analyzed. The results show that the reflection coefficients increase, while the transmission coefficients decrease, with the density and elastic modulus of the in-filled material. The vibration isolation effect is clearly better than that without trenches. In a certain width range, the transmission coefficient and vertical acceleration levels decrease with the increase of trench width. The influences of the transmission coefficient and the vibration isolation effects are not clear with the trenches’ depth variation. The vertical vibrations of the ground pick-up point are all smaller than those without in-filled trenches.

Highlights • The minimum value method in the sense of least squares method is proposed to satisfy the contact condition that the residual of the contact surfaces on both sides of the in-filled trench is zero, and the reflection and transmission coefficients of the Rayleigh waves on the contact surface are theoretically derived. • The calculation formulas of ground point displacement are derived. • A train-track-soil-infilled trench numerical analysis model was established for the vibration isolation analysis of train induced environmental vibrations. • The influence of the variation of infilled trench parameters is obtained.