Application of Periodic Theory to Rows of Piles for Horizontal Vibration Attenuation

One of the most important phenomena in periodic structures is the existence of the band of frequency gaps (BFGs). Elastic waves with frequencies in BFGs cannot propagate in the medium. Therefore, the BFGs can be used to reduce the dynamic response of structures behind periodic pile barriers. Although many achievements have been reported on piles as barriers, the periodic nature of rows of piles has not been considered thus far. In the present paper, the periodic theory of solid-state physics is introduced. The BFGs of two-dimensional periodic rows of piles are obtained. The effect of physical parameters such as soil density and elastic modulus, as well as the geometrical parameters of pile barriers on the BFGs, was investigated. The results show that vibrations can be greatly reduced within the range of the BFGs. Increasing the filling fraction or choosing different configurations can achieve wider BFGs. Moreover, periodic pile barriers with softer soil and a larger periodic constant can produce the lower bound frequency.