Analysis of Isolation Ground Vibration by Graded Wave Impeding Block under a Moving Load

Qiang Ma,Feng-Xi Zhou

doi:10.1155/2018/4989584

Abstract

Combined with the coordinate transformation, the dynamic governing equations for elastic foundation under a moving load are established by using the reverberation ray matrix method, and the isolation effect of a graded wave impeding block is studied. The displacement and the stress are obtained in the time domain by using numerical inverse Fourier transformation. Via numerical examples, the effectiveness of vibration isolation of graded wave impeding block is compared to conventional single phase solid homogenous wave impeding block. The results show that compared with the single phase solid homogenous wave impeding block isolation system, the graded wave impeding block can effectively reduce the vibration amplitude and has more advantages and is effective under a moving load.

Highlights

With the rapid development of urbanization and modern industry, ground vibration caused by moving load is becoming more and more frequent and it has become public considerable attention and engineering concern [1]
The effectiveness of three different wave barriers, namely, the open trench, in-filled trench, and elastic foundation, in reducing the ground vibrations caused by the passage of trains is studied [3,4,5,6,7], which indicate that open trenches are more efficient than in-filled trenches or soil stiffening-even at low frequencies
Takemiya [11] studied the response on the surface of the ground in the time domain with a Ricker wavelet type loading by using a boundary element model; their results showed that an effective width of the wave impedance block (WIB) should be chosen in relation to the wavelength of the given load

Summary

Introduction

With the rapid development of urbanization and modern industry, ground vibration caused by moving load is becoming more and more frequent and it has become public considerable attention and engineering concern [1]. The effectiveness of three different wave barriers, namely, the open trench, in-filled trench, and elastic foundation, in reducing the ground vibrations caused by the passage of trains is studied [3,4,5,6,7], which indicate that open trenches are more efficient than in-filled trenches or soil stiffening-even at low frequencies. Chouw and Schmid [8, 9] firstly suggested placing an artificial bed rock called “wave impeding block” (WIB) under the vibration foundation to screen the low frequency vibrations in the wave propagation regime Their results showed that the WIB was more effective at low frequencies than a buried wall barrier of similar dimensions. In this study, based on the FGMs, the isolation effect of graded WIB on reducing vibration induced by a moving load in elastic foundations is studied.

General Solution of Elastic Medium under Moving Load

Reverberation Ray Matrix Method

The Numerical Example and Discussion

Conclusions