Research purposes:The metro is under construction in a city,in order to get credible prediction accuracy for vibration response of neighboring constructions with this city metro,it is necessary to develop systematic research on environmental vibration along this city metro with comparatively special geological condition.Accordingly,two subsystem model,the vehicle-track coupled model of vertical vibration and the tunnel-soil-construction models of 3D FEM are established base on third kind of soft soil site of this city.Vibration responses of neighboring constructions are predicted reference to the parameters of this city metro.Research conclusions:(1) Vibration responses of neighboring constructions mainly reflect structural self-vibration,while there are rebound zones of middle-high frequency in the low levels of the constructions.(2) Train speed and single-double track have significant effects on peak acceleration,but have no significant effect on the vibration shape of the constructions.(3) The horizontal distances from multistoried construction to the centerline of the two tunnels is within 5 m,middle-highrise and highrise constructions are within 10 m,or range from 30 m to 40 m in vibration amplification zone,orthe metro train speed is over 60 krn/h,the floor accelerations of constructions may surpass vibration limit of related specification,so further vibration control is required to apply.(4) The relevant research results can provide atheoretical and technical support for design,construction and vibration control of metro environmental system on this city or geological condition similarities.%研究目的:某城市地铁正在建设,为取得较为可靠的地铁运行对邻近建筑振动影响的预测精度,有必要对地质条件较为特殊的该城市地铁沿线开展特定研究.本文针对该城市中软Ⅲ类场地土,建立地铁列车+轨道垂向耦合振动数值模型及隧道+土体+建筑有限元模型,参考该城市地铁参数,对邻近地铁的一般建筑在地铁运行时的振动响应作出理论预测.研究结论:(1)地铁邻近建筑的振动主频体现为结构的自振频率,且建筑低层存在地铁激励的中高频反弹区;(2)列车车速和单双线运行将显著干预邻近建筑的振动响应峰值,但对建筑的振动形态无明显影响;(3)多层建筑至隧道中心水平距离在5 m范围内,小高层与高层建筑在10 m范围内或30～40 m的振动放大区内,车速超过60 km/h时,邻近建筑全部或部分楼层振动响应可能超越相关振动限值,需进一步考虑减振控制;(4)该研究结论可为地质条件相似地区的地铁设计施工及未来的振动控制提供理论和技术支持.
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