Surface-wave attenuation by periodic pile barriers in layered soils

The purpose of this study is to investigate surface-wave isolation by periodic piles from the perspective of attenuation zones. There are three major components. The first is the dispersion equation, which is derived based on periodic theory of solid-state physics. The second component is the main new part of this paper. Finite element method is adopted to calculate the dispersion relation and attenuation zones for surface waves in a periodic pile and layered soil system. Moreover, effects of geometric parameters on attenuation zones and the amplitude reduction spectra are thoroughly investigated. As a result, harmonic responses show that the isolation region on amplitude reduction spectra is consistent with the theoretical attenuation zone. The third component is the feasibility of ground vibration isolation by periodic pile barriers, which is verified in the time domain by investigating train-induced ground vibrations. Using the concept of attenuation zone, one can manipulate the propagation and attenuation of surface waves artificially. This work provides a new insight into the design of periodic piles as wave barriers.