VIBRATION REDUCTION FOR PLANE WAVES BY USING PERIODIC PILE BARRIERS

Many researchers have analyzed the screening effectiveness of a row(s) of piles and used them to reduce the environmental vibrations. However, the periodic nature of rows of piles has been neglected. Piles that are arranged in a periodic configuration constitute a type of periodic structures. Band of frequency gaps (BFGs) exists in these periodic structures. Elastic waves with frequencies in the range of the BFGs cannot propagate in the medium. In this paper, the theory of periodic structures is utilized to study the vibration reduction by using rows of piles. The plane wave expansion method and COMSOL program are used to study the BFGs of two-dimensional (2D) three-component periodic pile barriers. The effect of filling fraction on the first complete BFGs is investigated. In order to verify the effectiveness, a 2D pile-soil finite element model is built, and input loads with different frequencies are considered. Theoretical analysis and numerical simulation show the frequency zones, of vibration reduction are consistent with the BFGs. The present investigation provides a new method for designing pile barriers to block mid-frequency vibration due to train.