“桥建合一”型地铁高架车站振动舒适度研究

Vibration serviceability of the subway elevated station of“combination of bridge and construction”type

"桥建合一"型地铁高架车站的轨道梁刚接在站房结构框架梁上,存在严重的车致振动舒适度问题。为了研究列车过站时"桥建合一"型地铁高架车站的振动舒适度规律,以某典型侧式"桥建合一"型地铁高架车站为研究对象,采用数值计算软件Matlab建立27自由度列车模型,采用有限元软件Ansys建立车站有限元模型,基于分离迭代法实现列车-车站的耦合作用,并对比实测数据验证列车-车站耦合振动分析模型的准确性。采用已验证的列车-车站耦合振动分析模型计算列车到发站时站房的振动舒适度敏感点,并研究列车车速、楼板厚度和桥墩跨度参数对站房振动舒适度的影响。研究结果表明:"桥建合一"型地铁高架车站的结构动力特性具有特殊性,典型楼板的1阶竖弯频率为28.91 Hz,是高铁客运站的4.7~7.7倍;站厅层振动舒适度敏感点位于结构缝附近和车站端部悬挑区域,列车到站时站厅层振动超标最大为32%;站房的车致振动相应总体上随列车车速的增加而增大,列车正线过站时60~80 km/h速度区间与列车会车过站时20~40 km/h和60~80 km/h速度区间的楼板振动增幅较为显著;楼板的车致振动在其自振频率附近会产生"共振效应",楼板厚度参数对楼板自制频率的影响较小,桥墩跨度参数对楼板自振频率的影响较大,合理设计桥墩跨度可以有效避免楼板产生"共振效应"。

The rail beam of the subway elevated station of“combination of bridge and construction”side-type was just connected to the frame beam of the station house,which had a serviceability problem caused by vehicle vibration.In order to study the vibration serviceability rule of the“combination of bridge and construction”elevated subway station when the train passes the station,a typical side-type“combination of bridge and construction”elevated subway station was taken as the research object.The numerical calculation software Matlabwas used to establish the 27 d of the train model.And the finite element software Ansys was used to establish the finite element model of the station.The train-station coupling was realized based on the separation iterative method,and the accuracy of the train-station coupling vibration analysis model was verified by comparing the measured data.A validated train-station coupling vibration analysis model was used to calculate the sensitive points of vibration serviceability of station house when train arrives at departure station.The effects of train speed,floor thickness and pier span on vibration serviceability of station house were studied.The results show that the structural dynamic characteristics of the“combination of bridge and construction”metro elevated station are special.The frequency of the first vertical bending of the typical floor is 28.91 Hz,which is 4.7~7.7 times of that of the high-speed railway passenger station.The sensitive points of vibration comfort of the station hall floor are located near the structure joints and the overhanging area of the station end.When the train arrives at the station,the vibration of the station hall floor exceeds the maximum of 32%.The vehicle-induced vibration of station house increases with the increase of train speed on the whole.The floor vibration increases significantly in the speed range of 60~80 km/h when the train is passing the station and in the speed range of 20~40 km/h and 60~80 km/h when the train is passing the station.The vehicle-induced vibration of the floor will produce a“resonance effect”near its natural vibration frequency.The thickness of the floor has little influence on the self-made frequency of the floor,while the pier span has a great influence on the natural vibration frequency of the floor.The rational design of the pier span can effectively avoid the“resonance effect”of the floor vibration.