Effect of homogeneous coated layer on periodic barrier for Rayleigh wave isolation

Abstract

Ambient vibrations induced by vehicles and construction activities can caused a significant adverse impact on building safety and human health. Periodic barriers based on phononic crystals (PC) have a broad application perspective to attenuate the propagation of Rayleigh waves caused by ground vibrations. However, due to the limited size of the units, it is difficult to create an efficient bandgap for attenuating low-frequency ground vibrations. Therefore, the present work aims to develop an innovative design that can significantly increase the efficiency of periodic barriers. To achieve this goal, we proposed a one-dimensional PC consisting of Eps geofoam and soil. The surface of the PC coated with a homogeneous layer composed of soil or concrete. The band structures of the proposed periodic barriers are calculated using the plane wave expansion method. The results are verified by 2D finite element simulation. The numerical results show that the height and density of the cover layer play an important role in the formation of the bandgap. Further, influence of initial stress and Young's modulus on the bandgap is analyzed. Finally, the transmission spectrum of Rayleigh waves is calculated and the vibration reduction property is discussed. The numerical results demonstrate that the phononic crystal coated with concrete layer can improve the vibration mitigation efficiency. This work could provide an interesting solution for periodic barriers made up of smaller numbers of elements.