ISSN 1000-3665 CN 11-2202/P

    郑西高铁地面振动实测分析及隔振沟效果研究

    Ground vibration test of the Zhengzhou-Xi’an high-speed railway and analyses of the vibration isolation trench effect

    • 摘要: 高铁列车动载会引起环境振动问题。为研究高速列车运行在高架段和路堤段引起的环境振动差异,文章对郑西线高速铁路展开现场测试,对比分析高架段和路堤段地面振动特征及其衰减规律。测试结果表明,路基段的振动响应大于高架段,高架段近场区衰减作用高于路堤段近场区域。振动传播过程中存在多次反弹增大现象,路堤段地面振动反弹增大位置滞后于高架段。高架段和路堤段的二次反弹增大率均明显大于一次反弹增大率。Z振级随距离的衰减符合对数衰减规律,拟合得到黄土地区Z振级衰减公式,最大偏差均出现在反弹增大区。引入无限元-黏弹性耦合边界条件,建立路堤段三维轨道-土体-隔振沟数值模型分析高速铁路隔振沟对减隔振的影响。研究发现空沟对中高频(30~60 Hz)振动波的隔振效果较低频(1~20 Hz)振动波明显,其具有低通滤波作用。空沟比填充沟隔振效果好,但是考虑到沟壁的稳定性,可在空沟中填入软质材料。研究成果可为高速铁路的设计及其环境振动的评价和控制提供参考。

       

      Abstract: The dynamic load of high-speed railway train can cause environmental vibration problems. In order to study the environmental vibration effect caused on the viaduct bridge section and embankment section by high-speed train, the field test of the Zhengzhou - Xi’an high-speed railway is carried out, and the ground vibration characteristics and attenuation law of viaduct bridge section and embankment section are compared and analyzed. The test results show that the vibration response of the embankment section is greater than that of the viaduct bridge section, and the attenuation effect in the near-field area of the viaduct bridge section is higher than that in the near-field area of the embankment section. There are multiple rebound increases in the process of vibration propagation, and the ground vibration rebound of the embankment section lags behind that of the viaduct bridge section. The increase rate of secondary rebound in the viaduct bridge section and embankment section is significantly greater than that of primary rebound. The attenuation of Z vibration level with the distance conforms to the law of logarithmic attenuation. The Z vibration level attenuation formula in the loess area is obtained by fitting, and the maximum deviation appears in the rebound increasing area. The infinite element-viscoelastic coupling boundary is introduced to establish a 3D track-soil-vibration isolation trench numerical model of the embankment section. The influence of vibration isolation trench on vibration reduction and isolation of high-speed railway is analyzed. The results show that the vibration isolation effect of empty trench on the medium and high frequency (30 - 60 Hz) vibration wave is more obvious than that of low frequency (1 - 20 Hz), and it has the function of low-pass filtering. The vibration isolation effect of empty trench is better than that of filled trench, but soft materials can be filled in the trench considering the stability of trench walls. The research results can provide references for the design of high-speed railway and the evaluation and control of environmental vibration.

       

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