小半径曲线地段地铁列车运行对建筑物的振动影响分析

Analysis of the Vibration Influence of Subway Trains on Buildings in a Small Radius Curve Section

针对地铁小半径曲线地段列车运行对建筑物振动影响问题,运用车辆-轨道耦合动力学计算获得振源激励,建立列车动荷载作用下隧道-地层-建筑物有限元模型,并结合现场测试验证了模型的可靠性,研究列车运行对浅基础、短桩基础、长桩基础以及筏形基础建筑物振动响应的规律。结果表明:随着楼层的增加,建筑物的横向振动表现为先减少后增大,垂向振动表现为逐层增大的趋势;建筑物的振动在中高频成分(>20 Hz)有所增加,低频成分则有所衰减;垂向振动要大于横向振动,楼柱的振动要比楼板的振动更加明显;不同基础条件下的建筑物垂向振级由大到小的排序为筏形基础>浅基础>短桩基础>长桩基础,横向振级由大到小的排序为浅基础>短桩基础>长桩基础>筏形基础,长桩基础对降低加速度振级最为有利。

In this study,a dynamic model of vehicle-track coupling vibration in a small-curve radius track is established.The calculated reaction force of the coupler was used as the excitation source,and a finite element model of the tunnel-stratumbuilding under the action of a metro was established.The reliability of the model was verified by measuring the vibration response data of the tunnel wall in a curved track during actual train operation.The basic basic foundation types in building construction and the influence degree of the vibration response of the building was modified by adopting four basic forms of the building:short shallow foundation,short pile foundation,long pile foundation,and raft foundation.These mentioned forms were compared and analyzed.Research results indicated that as the number of floors increased,the building lateral vibration initially decreased.Subsequently,the vibration increased as the vertical vibration increased on each floor.The vibration of the building increased over the medium-and high-frequency components(>20 Hz)while the low-frequency components decreased.In general,vertical vibration was greater than lateral vibration,while column vibration was greater than floor vibration.The vibration levels of the four working conditions in descending order are as follows:raft foundation>shallow foundation>short pile foundation>long pile foundation.On the other hand,the order of lateral vibration order from largest to smallest is as follows:shallow foundation>short pile foundation>long pile foundation>raft foundation.Overall,long pile foundation is the most favorable form for reducing acceleration vibration level.