铁道科学与工程学报2024，Vol.21Issue(6)：2261-2271,11.DOI:10.19713/j.cnki.43-1423/u.T20231413
橡胶颗粒改良流态粉煤灰路基隔振性能研究
Investigation on the vibration isolation performance of flowable fly ash subgrade improved by rubber particles
摘要
Abstract
In order to solve the problem of subgrade and foundation vibration damage induced by railway train operation,a new type of flowable fly ash subgrade improved by the rubber particles(FAR)was designed based on the principle of damping energy dissipation.The FAR subgrade material,satisfying the requirements of the engineering performance,was prepared by laboratory mixture tests.By using the transient vibration excitation method,the damping ratio of the FAR subgrade material was tested,the influence of the rubber particles on the damping characteristics of FAR subgrade material was analyzed,and the damping energy dissipation mechanism of the FAR subgrade was revealed.A 3D coupled numerical model of track-subgrade-foundation was established by COMSOL finite element software.The dynamic stress and vibration acceleration propagation laws of the FAR subgrade when the rubber particle content was 5%,10%and 15%were compared with those of the ordinary subgrade,and the vibration isolation performance of the FAR subgrade was analyzed and verified.The results show that the strength and dry density of the FAR subgrade material are reduced with the addition of the rubber particles,and the basic physical and mechanical properties of the subgrade can satisfy the requirements of railway engineering applications when the rubber particle content does not exceed 15%of the solid mixture mass.The viscoelastic characteristics of the rubber particles can cause the loss or attenuation of the dynamic stress in the FAR subgrade and the subgrade damping ratio increases with the increase of the rubber particles.When the rubber particle content is the same,the smaller the rubber particle size is,the larger the damping ratio of the FAR subgrade would be.On this basis,the mixture with 150 mesh rubber particles was recommended.As compared to the ordinary subgrade,the dynamic stress levels in the subgrade bed bottom layer,subgrade soil,and foundation soil of the FAR subgrade all reduce,and the attenuation amplitude ranges from 10%to 30%,which can effectively avoid reducing the occurrence of the subgrade dynamic deformation,foundation vibration settlement and other problems.In the main frequency range of the FAR subgrade vibration,the ground vibration acceleration level is reduced by 2 to 6 dB in general while it can reach as high as 83 dB,which verifies the good vibration isolation performance of the new FAR subgrade.The research results provide reference for the vibration isolation design and the safe operation of the railway FAR subgrade.关键词
流态粉煤灰/橡胶颗粒/铁路路基/隔振性能/阻尼比Key words
flowable fly ash/rubber particles/railway subgrade/vibration isolation performance/damping ratio分类
建筑与水利引用本文复制引用
厉超,李文杰,顾玉仑,张思峰,李书俭,张宇轩..橡胶颗粒改良流态粉煤灰路基隔振性能研究[J].铁道科学与工程学报,2024,21(6):2261-2271,11.基金项目
山东省自然科学基金资助项目(ZR2022QE082) （ZR2022QE082）
山东省交通运输科技计划项目(2021B89) （2021B89）
