Isolation Of Rayleigh Waves By Periodic Wave Barriers In Layered Soil With Initial Stress

Periodic structures can inhibit the propagation of elastic waves in its attenuation domain.Therefore,the periodic wave barrier can be considered for environmental vibration control in practical engineering.In recent years,the researches of periodic wave barrier in environmental vibration control have made a lot of progress and achievements,but there are still many problems to be improved.First of all,the current researches on periodic wave barrier are mostly carried out under the assumption of homogeneous soil.Soil in practical engineering is mostly layered,but there are few researches on layered soil,especially saturated layered soil.Next,due to the influences of soil excavation,soil re-consolidation,engineering construction and the upper load of the structure,the soil and structures in practical engineering usually have initial stress.However,the existing researches on periodic wave barrier mostly ignore the influence of initial stress.Although some studies have considered the initial stress,most of these studies focus on the attenuation of body waves by periodic wave barriers,and rarely consider the attenuation of surface waves,which play a leading role in environmental vibration control.Based on the above situations,this paper will study the isolation of Rayleigh waves by periodic wave barriers in single-phase and saturated layered soils with initial stress.The main contents are as follows:(1)With the help of the partial differential equation(PDE)module in the finite element software COMSOL Multiphysics,a new module was developed to calculate the complex dispersion curve of periodic structures with initial stress and analyze its response in frequency domain and time domain,which provided a new way for the study of periodic structures.(2)Using the new module,the complex dispersion curves of periodic continuous wall wave barrier and periodic pile wave barrier in layered soil with initial stress were successfully solved.The attenuation domains of the two wave barriers on Rayleigh waves were determined,and the influences of related parameters on the attenuation domains were analyzed.(3)Considering the initial stress,a two-dimensional numerical analysis model of the periodic continuous wall wave barrier and a three-dimensional numerical analysis model of the periodic pile wave barrier in layered soil were established.The frequency domain response and time domain response of the two models were numerically simulated with the help of the new developed module,which verified that the two kinds of periodic wave barriers were effective in isolating Rayleigh waves.The results show that the existence of initial stress makes the attenuation domain of the periodic wave barrier move to low frequency,and the larger the initial stress value is,the more obvious the attenuation domain moves to low frequency.Therefore,it can be considered to regulate the isolated Rayleigh wave frequency band by properly adjusting the load value of the upper part of the wave barrier.When the vibration frequency is within the theoretical attenuation domain of the periodic wave barrier,the vibration will be attenuated obviously,and increasing the number of barrier rows is conducive to achieving better damping effect.This work not only reveals the influence law of initial stress on vibration isolation performance of periodic wave barrier,but also provides a new way to analyze periodic structure and broaden the research scope of periodic structure.