高铁滨海北站路基段环境振动试验研究与数值分析

摘要

为了研究高速铁路列车在路基段运行时引起的周边环境地面上的竖向振动特性和传播规律,进行现场试验和数值分析.实测结果表明:高速铁路路基段周边环境地面不同距离测点的Z振级均小于78 dB,振动并没有随距离衰减,只是在距离外轨30～60 m范围内有减弱;距离线路外轨30 m外的环境振动的频谱主峰频率以小于10 Hz的低频为主;振动频谱中并没有显现出高频振动衰减快、低频振动衰减慢的规律.基于FLAC3D的数值分析结果与实测值吻合良好,验证了模型的合理性,并分析群桩加固区对振动的影响,结果表明:在路基段采用群桩基础对地基进行加固,可有效降低高速铁路列车运行对路基段周边环境振动的影响.%Field tests and numerical analysis of a high-speed railway are carried out to study the characteristics and propagation of train-induced ground vibrations.The conclusions of field test are as follows.The vertical vibration is less than 78 dB from all test points distributed in different distance along the subgrade section of the high speed railway,and the vibration is not attenuated with the changes of the distance,and attenuation only presents within 30 ～ 60 m from the outer rail.The vibration frequencies of ground soil are mainly concentrated in the range of 0 ～ 10 Hz.During the spreading process,it is not showed that high frequency vibrations attenuate rapidly while low frequency vibrations attenuate slowly.The results of numerical analysis using FLAC3D are in good agreement with the field tests,which verifies the rationality of the numerical analysis model.The influence of pile reinforcement area on the vibration is studied using numerical analysis,and the results show that the reinforcement by pile foundation in the section of subgrade can effectively reduce the vibration impact of high speed trains on subgrade section of high speed railway.