Model Test And Influence Facors Analysis Of Vibration Reduction For Regular-hexgon Arranged Periodic Pile Barriers

The vibration waves generated by the artificial vibration source propagate along all directions in the soil,which affects the adjacent buildings、pipelines and precision instruments and even harms human health.Therefore,it is particularly necessary to effectively reduce the hazard of artificial vibration and control vibration pollution.From the point of view of the vibration propagation path,referring to the characteristics of the periodic structure attenuation domain,the model tests and numerical simulations of the periodic row pile barriers system are carried out in this paper.The influence of periodic piles with the regular hexagonal arrangement on the attenuation effect of the vibration and the frequency range of the attenuation domain is analyzed.The validity of the numerical model for periodic piles-soil dynamic interactions is verified and the influence factors of vibration reduction for periodic piles are studied.The main results are as follows:(1)The basic principles of vibration reduction for the periodic pile barriers,the Bragg scattering mechanism,and the local resonance type mechanism are introduced;the periodic piles-soil dynamic interaction research methods are described;the method of combining the model test and the numerical simulation is determined to be used in this paper.(2)The model test of periodic pile barriers was conducted on the second underground floor of the Orbital Vibration Reduction and Control Laboratory.The model test used the periodic steel pipe piles with regular hexagonal arrangement and the actual silty clay.In the test,the accelaretion response of ground soil with the piles row and without piles row were measured separately,and the vibration reduction effect and attenuation domain characteristics of periodic row piles are analyzed.(3)Based on the parameters measured from the model test,a three-dimensional finite element-infinite element numerical model for the periodic steel pile barriers-foundation soil is established by using the ABAQUS software,and moreover the vibration reduction effect of the regular row-pile barrier arranged on the six sides is analyzed.By comparing the numerical simulation results with the model test results,the effectiveness of numerical model is verified of this paper.(4)To study the attenuation law and influence factors of the vibration reduction of the periodically rowed piles arranged on the six sides,the three-dimensional finite element-infinite element numerical model of the periodic row with actual size and theearth soil is established.The acceleration responses of the soil surface produced bythe moving load are calculated.Furthermore,the influence of pile length,pile diameter and pile spacing on the vibration reduction effect of periodic row piles are analyzed.