轨道型式对地铁与建筑物共建结构振动响应的影响

Influence of Different Track Types on the Vibration Response of the Jointly-Built Structure of Subway and the Buildings

以上海某地铁站与建筑物共建工程为例,现场实测由于地铁运行引起的车站站厅层、上部结构各楼层的动力响应,建立道床—共建结构—地基二维动力有限元模型。通过对比分析计算和实测的共建结构竖向振动加速度的时域谱和1/3倍频程振级谱,探讨普通轨道、科隆蛋高弹扣件轨道和钢弹簧浮置板轨道在引起共建结构振动响应方面的差异。研究结果表明:采用科隆蛋高弹扣件轨道时,共建结构同一位置的加速度峰值约是普通轨道的1/2,而固有频率为6 Hz的钢弹簧浮置板轨道的加速度峰值仅为普通轨道的1/10左右,但钢弹簧浮置板轨道引起的振动周期和持时相对较长;科隆蛋高弹扣件轨道与钢弹簧浮置板轨道均有明显的减振效果,所不同的是前者对25 Hz以下、后者对25 Hz以上频段的竖向振动有较好减振效果;钢弹簧浮置板固有频率的变化对该共建结构振动响应的影响很小。

Based on a project in Shanghai that a subway station and building were jointly constructed, the dynamic response of the station hall and the upper floors of the structure by metro operation was field measured. The two-dimensional dynamic finite element model of railway track bed-jointly built structure-foundation was established. Through comparatively analyzing the calculated and the field tested time-domain spectrum and 1/3 octave spectrum of the vertical vibration acceleration of the jointly-built structure, the differences of the vibration response in the jointly-built structure aroused by the general track, Cologne-egg high-elastic fastener track and steel-spring floating slab track were investigated. The main conclusions show that the peak acceleration amplitude of the jointly-built structure is about half of that of the general track at the same position when adopting Cologne-eggs high-elastic fastener. The peak acceleration amplitude of steel-spring floating slab track whose natural frequency is 6 Hz is only about 1/10 of that of the general track at the same position. However, as for the cycle and the duration of the vertical vibration, steel-spring floating slab track is relatively longer. The vibration-reduction effect of both Cologne-egg high-elastic fastener track and steel-spring floating slab track is obvious. The difference is that the former （the latter） is provided with better vertical vibration-reduction effect on the vibration of the frequency band below 25 Hz （above 25 Hz）. The change of the natural frequency of steel-spring floating slab track has little effect on vibration response with regard to this jointly-built project.