基于薄片有限元-无限元耦合模型的地铁列车振动环境影响分析

Metro train-induced vibration influences on surrounding environments based on sliced finite element-infinite element coupled model

鉴于地铁运营引发隧道及地层沿线路纵向的振动水平及特性不甚明确,应用薄片有限元-无限元耦合模型对地铁列车运营引发隧道基底、隧道壁及地表在垂直于线路的水平方向、铅垂方向及线路纵向三个方向上的振动响应进行高精度分析及比较。分析结果表明:(1)地铁列车运营引发横向、垂向及纵向三个方向6 Hz以下的低频振动在地表均衰减得极其缓慢,且地表三个方向的振动速度、加速度响应具有相似的频率成分;(2)列车运营引起隧道壁的纵向振动响应在1~100 Hz频段内较小,在该频段内的大部分频率点处,其响应甚至小于地表的纵向振动响应;(3)在隧道基底及隧道壁,由列车运营引发的纵向振动响应在1~100 Hz频段以内显著小于由其引发的垂向振动响应,但在地表,由列车运营引发的纵向振动响应具有同横向、垂向响应相当的量值。

Because level and characteristic of metro train-induced tunnel and ground vibrations in the longitudinal direction along a subway line are not very clear,comprehensive high accuracy analyses and comparisons for metro traininduced vibration responses of tunnel base,tunnel wall and ground surface in all three directions were performed with the sliced finite element-infinite element coupled model. The results showed that metro train-induced lower frequency vibrations below 6 Hz on ground surface in the transverse direction,the vertical one and the longitudinal one are attenuated very slowly,the frequency components of ground surface vibration velocity and acceleration responses in three directions are similar; train-induced longitudinal vibration responses of the tunnel wall are smaller in the frequency range of 1-100 Hz,at most frequencies in this range,the responses of the tunnel wall are even smaller than those of the ground surface in the longitudinal direction; on the tunnel base and the tunnel wall,the train-induced vibration responses in the longitudinal direction in the frequency range of 1-100 Hz are significantly smaller than those in the vertical direction,but on the ground surface,the train-induced vibration responses in the longitudinal direction have comparative values to those in the transverse direction and vertical one.