基于监测数据的铁路钢桁梁车致支座位移响应分析

Analysis on Vehicle-induced Bearing Displacement Response of Railway Steel Truss Girder Based on Monitoring Data

摘要:

为了分析采用温度-位移关系模型来评估活动支座滑移性能的局限性，开展了列车作用下铁路钢桁梁支座位移响应特征的研究。基于桥梁健康监测系统，对比了温度和列车综合作用下某钢桁梁1#~3#支座位移响应的差异，并分析了产生差异的原因；针对受列车影响显著的3#支座，建立了位移响应特征与列车作用工况的映射关系，提出了一种可以基于车致支座位移来识别支座滑移状态是否异常的方法。研究表明：列车荷载破坏了温度与3#支座位移的滞回路径，难以利用温度-位移模型来评估3#活动支座的滑移状态；由列车荷载引起的3#支座位移响应特征可分为4种类型，并且有唯一的列车荷载工况与之对应；3#支座位移终态在一个区间范围内往复振荡，该振荡区间的长度可用于活动支座滑移状态是否异常的判别，也为桥梁活动支座滑移状态的评估提供了一种新思路。

Abstract:

In order to analyze the limitation of temperature-displacement relational model in evaluating the sliding performance of movable bearing, the bearing displacement response of railway steel truss girder under the train load is studied. Based on the bridge health monitoring system, the difference of displacement response of 1~3# bearings of a steel truss girder under the combined action of temperature and train is compared, and the causes of the difference are analyzed. The mapping relationship between the displacement response characteristics and the train operating conditions is established for 3# bearing which is significantly affected by train. A method for identifying the abnormal sliding state of bearing based on the vehicle-induced displacement is proposed. The research shows that the train load destroys the hysteretic path of temperature and 3# bearing displacement. It is hard to use the temperature-displacement model for evaluating the slipping state of 3# movable bearing. The 3# bearing displacement response characteristics caused by train load can be divided into four types, and there is a unique vehicle load condition corresponding to it. The final state of the 3# bearing displacement oscillates is in a range. The length of this oscillating area can be used to distinguish whether or not the slipping state of movable bearing is normal, and also provide a new idea for the evaluation of slipping state of movable bearing of the bridge.