地铁交通引起的建筑物振动实测与数值模拟分析

In situ measurement and numerical simulation for the environmental vibration induced by urban subway transit

结合上海软土地区典型工程实例,现场实测地铁减振前后隧道内及邻近建筑物内的振动加速度,据此对地铁轨道减振效果进行分析评估。在此基础上,提出了有限元与无限元相结合的数值分析简化预估方法,预测地铁交通激发的周边建筑物振动响应,并将计算分析结果与实测结果进行对比,分析地铁交通引起邻近建筑物振动随楼层的变化规律,探讨不同因素对建筑物振动响应的影响。研究结果表明:(1)采用Vanguard扣件较科隆蛋扣件隧道内道床振级降低约16 dB,建筑物楼板中的振级降低10.9~21.1 dB,减振效果明显;(2)随着楼层的增高,楼板中振动的振级呈现先减小后增大的现象;(3)采用提出的数值分析得到的建筑物楼板振级和实测结果吻合较好,表明分析方法合理可行,为预测地铁周边建筑物振动提供一种快速简便的分析方法。

According to the soft soil engineering cases in Shanghai,several vibration field measurements of the vertical acceleration of tunnels and buildings is carried out to evaluate the damping effect of urban subway transit.Then,the combined finite element method and the infinite element method are adopted to investigate the variation of structural vibration induced by urban subway transit with the floor level.Comparing the numerical results and the field measurement,it can be concluded that:1)The vibration level in tunnel decreases by 16 dB and the vibration level in the floor decreases by 10.9-21.1 dB after the damping,which indicates that the damping effect is obvious;2)The vibration level in the floor decreases and then increases as the floor increases;3)The vibration level of the floor calculated by the proposed numerical model shows a better consistency with the measurement result,which shows the proposed analysis method is reasonable and feasible,and it provides an effective way for predicting the vibration level of buildings around the subway.