富水卵石土地层盾构隧道运营对环境影响分析

Analysis on Environmental Impact of Shield Tunnel Operation on Water-rich Pebble Stratum

针对富水卵石土地层颗粒分布不均、卵石含量高等特点,以成都某地铁区间隧道工程为背景,采用FLAC3D软件分析了列车振动荷载作用下地表及建筑物的竖向动力响应特性。结果表明:随着距轨道水平距离的增大,地表竖向动力响应逐渐减弱,且在距隧道较近处衰减缓慢,在较远处衰减明显;整体上建筑物的动力响应随楼层升高有缓慢增大的趋势;随着水平距离的增加,同一楼层处的动力响应有显著的衰减现象,且距离越远衰减幅度越大;地表和建筑物的动力响应均集中在0～12 Hz和20～25 Hz两个频率带内,属于低频振动。研究结果可为进一步完善城市振动控制标准提供参考。

According to the characteristics of the uneven distribution of particles and high content of pebbles in water-rich pebble stratum,FLAC3D was used to analyze the vertical dynamic response characteristics of the surface and buildings under the vibration load of the train,which took a subway tunnel project in Chengdu as the background. The results show that with the increase of the horizontal distance from the orbit,the vertical dynamic response of the surface is weakened. The attenuation is slow when measuring points are near to the tunnel,and the attenuation is obvious when farther to the tunnel. Generally speaking,the dynamic response of the building amplifies slowly with the increase of storey numbers. With the increase of the horizontal distance,the dynamic response at the same floor has a significant attenuation,and the greater the distance is,the greater the attenuation is. The dynamic response of the surface and the building is concentrated in the 0 ~ 12 Hz and 20 ~ 25 Hz frequency band,which is low frequency vibration. The results can provide a reference for further improving the urban vibration control standard.