地铁列车运行振动对环境影响因素的参数分析

Parameters Analysis on Environmental Vibrations Induced by Subway Trains

采用4因素3水平正交设计的试验方法,基于解析的车轨耦合模型的动力学方法计算列车荷载,并建立三维动力有限元数值模型,讨论了不同影响因素(轨面埋深、扣件型式、行车速度、隧道型式)对地表振动影响的显著性程度,并分析地表响应特性及振动传播规律。结果表明:垂向振动是主要动力响应,且存在着传播较远的长周期含量,是低频振动的重要贡献;正交试验参数影响的显著性程度上,轨面埋深和扣件型式最显著,其次为行车速度和隧道型式,因此应在埋深因素影响阈值范围内尽量选择深埋,并选择合理的扣件以减少振动;地表振动随距离的增加逐渐衰减,30 Hz以上的频率分量振动衰减梯度较高,反映出土层的阻尼和滤波作用,衰减曲线并非单调递减,有一定起伏。

An orthogonal test under 4 factors and 3 levels is used to calculate the train load based on the analytical mod- el system coupled with vehicle ＆ track. By 3D FIE model- ing, the influence degree of different parameters （embed- ded depth of track surface, fastener type, train speed and tunnel form） to ground- borne vibration is presented. The characteristics of ground vibration response and the law of propagation are discussed as well. Results illustrate that the vertical vibration is the main response, and a long - period content with farther propagate contributes to the low-fre- quency vibrations. From the influence degree of different parameters in the orthogonal test, the embedded depth of track surface and type of fasteners are the most important factors, followed by train speed and tunnel form. The em- bedded depth is suggested as deep as possible but should bewithin its threshold, a good choice of fasteners has a signif- icant role to mitigate the vibrations. Since vibration on sur- face attenuates approximately by distance, the response a- bove 40 Hz decreases rapidly due to soil material damping. The decrease of attenuation curves is not monotonical but fluctuant.