Periodic Wave Barriers For Surface Wave Isolation In Saturated Viscoelastic Soils

With the rapid development of urban transportation in China,the hazards caused by ambient vibration have become more and more obvious,and most of these negative effects are caused by surface waves.To solve these problems,wave barriers have been widely used in ambient vibration reduction as an effective measure to isolate waves,and these studies,mostly based on the assumption of elastic soil,have confirmed that suitable wave barriers can substantially reduce the hazard of ambient vibrations.However,there is no perfectly elastic soil in nature,and soil is a material with viscous damping.Viscosity is essential to the dynamic response of the structure,so it is necessary to reveal the effect of viscosity on the periodic structure;in addition,in the areas such as high groundwater level or seashore,where the pores of the soil are completely occupied by water,saturated soil becomes the main site type in the area.But unfortunately,the study on surface wave isolation by periodic wave barriers in saturated viscoelastic soil has not been reported.To this end,this paper focuses on this issue and the detail contents list as follows:(1)The intrinsic model of saturated viscoelastic soil is established by introducing Kelvin model.In combination with the partial differential equation module in the finite element software Comsol Multiphysic,the correctness of the analytical method for the surface wave complex band structure is verified by degrading the saturated soil into single-phase soil.(2)The complex band structure of surface waves in saturated viscoelastic soil with periodical in-filled trenches and pile barriers are respectively solved,and the attenuation properties of surface waves at different viscosities are explored.(3)The vibration reduction performance by periodical in-filled trenches and pile barriers in saturated viscoelastic soils is revealed in the frequency domain and time domain to further demonstrated the effect of viscosity on surface wave isolation.(4)The vibration reduction performance by different numbers of periodic wave barriers in saturated viscoelastic soil was studied.The results of the study show that the viscosity leads to the fact that all the imaginary part is greater than zero,which indicates that the surface waves are attenuated at every frequency;when the frequency of the surface wave is in the attenuation zone,there is limited further reduction after increasing the viscosity.However,outside of the attenuation domain,viscosity can substantially reduce the effect of surface waves,and the greater the viscosity,the more surface wave attenuation is,,which is more obvious at high frequency.The above conclusions are confirmed in the time and frequency domain response analysis,and it was also found that more periodic wave barriers are more effective in vibration reduction.