小半径曲线段浮置板轨道振动对邻近民居影响测试研究

Field Test Study on the Impact of Vibration on a Residential Building at Short Distance in Floating Slab Track Metro Section with a Small Radius

为评估小半径曲线浮置板轨道段地铁列车下穿振动敏感建筑造成的环境振动影响,对无锡地铁2号线近距离下穿一处民居进行现场测试,从加速度时程、频谱、有效值、1/3倍频程谱和最大Z振级(VLz,max)方面进行分析,探究民居不同楼层及不同平面位置处的振动响应规律。研究结果表明:(1)同楼层中远离线路的楼层中央加速度响应时程峰值明显大于靠近线路的楼层边缘处,而不同楼层的同一平面位置处,2楼加速度响应明显大于1楼;(2)由于浮置板轨道一阶固有频率及轮轨共振频率的影响,振源及民居不同测点加速度频谱峰值均出现在7 Hz及80 Hz附近;(3)不同楼层及不同层内平面位置的最大Z振级量值存在一定差异,各测点的平均最大Z振级在53.97~57.10 dB之间,小于规范限值67 dB。浮置板轨道在该小半径曲线段对地铁振动控制作用良好。

In order to evaluate the environmental vibration effects caused by the subway passing through a vibration-sensitive building in the floating slab track section with a small radius,a field test is carried out on a residential house at a short distance above Wuxi Metro Line 2.The vibration response of the residential house at different floors and different positions is investigated by analyzing the acceleration in terms of time domain,frequency domain,RMS,1/3 octave and maximum Z vibration level(VL_(z,max)).The results of test and analysis show that:(1)At the same floor,the peak acceleration response at the center of the floor is significantly greater than that at the edge of the floor,and the acceleration response of the 2nd floor is significantly greater than that of the 1st floor at the same in-plane position of different floors;(2)Due to the influence of the first order frequency and the resonance frequency of the floating slab track,the peak value of acceleration spectrum at different measurement points of the concerned building appears around 7 Hz and 80 Hz;(3)There are some differences in the VL_(z,max) of the measurement points at different floors and different in-plane positions,and the average VLz,max of each measurement point is between 53.97 and 57.10 dB,which is less than the limit of 67 dB,indicating that the floating slab track plays a good role in controlling the vibration in this small radius curve section.