研究目的：为研究大跨度斜拉桥在温度作用下的变形及其引起的长波不平顺对列车运行的影响,以泉州湾跨海钢混结合梁斜拉桥为研究对象,在其主梁截面布置温度传感器以监测主梁温度变化,利用ANSYS软件分析实测温度作用下的斜拉桥主梁竖向变形,将温度变形与轨道不平顺叠加且基于弹性系统动力学总势能不变值原理建立考虑该长波不平顺的车桥耦合模型,以研究长波不平顺对列车动力响应的影响、弦测法对其进行评价的适配性,以及温度变形极限条件下的对应限值。
研究结论：(1)温度监测系统共收集了1年的温度数据,将其分解为均匀温度和线性温差后,对应的温度变化范围分别为[5.82 °C,37.51 °C]和[2.36 °C,29.94 °C],主梁主跨跨中的最大竖向位移为28.6 mm,最小竖向位移为14.1 mm;(2)相比于未考虑温度作用,考虑了温度作用引起的长波不平顺的车桥耦合振动模型得到的列车轮重减载率、竖向加速度和竖向舒适度指标均有一定增大,竖向加速度增幅最为明显;(3)考虑了因列车运行引起的桥梁动态位移的影响后,60 m弦中点弦测法依然能够很好地体现列车振动响应,与车体竖向加速度响应相关性最好;(4)通过分析60 m弦的不平顺计算结果并进行验证,可知桥塔附近是双线行车时会车的危险位置;(5)在温度变形极限条件下列车的竖向加速度达到规范限值,对应的60 m弦矢度限值为7.22 mm;(6)本研究成果可为大跨度斜拉桥长波不平顺的评测方法选取及限值要求提供参考。

Research purposes: In order to study the deformation of long-span cable-stayed bridge under the action of temperature and the influence of long-wave irregularities on train response, Quanzhou Bay steel-concrete composite beam cable-stayed bridge which crosses sea was taken as the research object, the temperature sensors were arranged on the beam section to monitor the temperature changes of the beam, then the ANSYS software was used to analyze the vertical deformation of the beam when the cable-stayed bridge was under the action of measured temperature, which was added to the original irregularities. The vehicle-bridge coupled model considering the long-wave irregularities was established based on the principle of constant total potential energy of elastic system dynamics to study the influence of long-wave irregularities on train dynamic response, the adaptability evaluation by chord measurement method, and the corresponding limit value under the limit condition of temperature deformation.
Research conclusions: (1) The temperature monitoring system collects the temperature data for one year. After decomposing it into uniform temperature and linear temperature difference, the corresponding temperature variation ranges are [5.82 °C, 37.51 °C] and [2.36 °C, 29.94 °C] respectively. The maximum vertical displacement in the middle of the main span of the beam is 28.6 mm and the minimum vertical displacement is 14.1 mm. (2) Compared with the vehicle-bridge coupled vibration model without considering the temperature effect, the wheel load reduction rate, vertical acceleration and vertical comfort index of the train calculated by the model considering the long-wave irregularities caused by the temperature effect increase to a certain extent, and the increase of vertical acceleration is the most obvious. (3) After considering the influence of bridge dynamic displacement caused by train operation, the 60 m chord midpoint chord measurement method can still well reflect the train vibration response, and has the best correlation with the vertical acceleration response of the vehicle body. (4) Through the analysis and verification of the calculation results of the irregularities of 60 m chord, it is obvious that the dangerous position of passing vehicles when driving on double lines is near the bridge tower. (5) Under the limit condition of temperature deformation, the vertical acceleration of the train reaches the specification limit, and the corresponding 60 m chord vector limit is 7.22 mm. (6) The research results can provide reference for the determination of the limit and the selection of evaluation methods about long-wave irregularities for long-span cable-stayed bridges.