地铁列车进站减速段临近高层建筑室内响应影响分析

Analysis on Indoor Vibration Response of High-rise Buildings near Subway Train′s Deceleration Section

为研究地铁列车进站减速段临近高层建筑室内振动响应规律,沿列车减速方向在隧道内盾构与明挖交界位置前后开展振动源现场测试,并基于实测钢轨振动加速度对临近框筒结构酒店建筑室内楼板振动响应开展有限元计算与分析,同时比较减速和匀速过站时室内振动响应的差异。结果显示,沿车速降低方向,隧道壁垂向振动加速度主频向低频移动,且幅值显著降低,减速段3个断面洞壁最大Z振级VLZmax算术平均值分别为73.6 dB、74.6 dB和62.2dB;临近某25层酒店建筑室内楼板垂向振动加速度峰值随楼层升高呈现波动性变化的特征,减速工况下,裙楼首层近轨侧典型楼板位置处典型频带垂向振动加速度级沿列车减速方向依次降低7.9 dB和6.4 dB,而主楼室内振动并未呈现沿列车运行方向降低的趋势;与减速运行相比,列车匀速运行时,裙楼和主楼室内振动响应有所增大,且在低楼层进站端增大较为显著,裙楼典型位置室内振动最大Z振级增加量最大为9.6 dB,主楼典型位置最大Z振级差异可达4.8 dB,说明对车站临近建筑进行地铁振动影响分析时,应尤其注意沿列车减速方向的振动变化规律。

The indoor vibration of high-rise buildings near the deceleration section of subway when trains entering the station is studied.The vibration source is measured along the train deceleration direction near the junction between the tunneling shield and the open cut tunnel.The indoor vibration of a high-rise building of hotel is calculated by means of finite element simulation.The indoor vibration responses of the building when the trains passing through the station at constant speed and decelerating are analyzed respectively and compared each other.The results show that along the direction of vehicle deceleration,the main frequency of vertical vibration acceleration of tunnel wall shifts to low frequency,and the amplitude decreases significantly.The arithmetic average values of the maximum Z-vibration level(VLZmax)of three typical sections are 73.6 dB,74.6 dB and 62.2 dB respectively.The peak value of the indoor vertical vibration acceleration in the hotel building fluctuates with the rise of floor.Under the deceleration condition,near the rail side on the first floor of podium building,the vertical vibration acceleration level of typical frequency band decreases by 7.9dB and 6.4dB successively along the train deceleration direction,while the indoor vibration of the main building has no such a decreasing trend.Under the constant speed condition,the indoor vibration response at the typical positions of the podium and the main buildings increases,which is especially notable in lower floor near the station.The maximum amplitude of indoor vibration is 9.6dB in the typical position of the podium building,and the maximum Z vibration level difference in the main building can reach 4.8dB.The results indicate that special attention should be paid to the change of the vibration along the train deceleration direction when the indoor vibration of the buildings adjacent to the station is analyzed.