基于加速度监测的大胜关大桥车-桥共振分析

Vehicle-bridge Resonance Analysis of Dashengguan Bridge Based on Vibration Acceleration Monitoring

研究目的：桥梁结构的长期振动会直接影响桥梁服役状态和使用寿命，本文以大胜关大桥主梁振动为背景，研究高速列车通过时主梁振动加速度峰值与列车车速的相关性特征，重点讨论特定车速下大胜关大桥的共振特性，分析影响大胜关大桥共振特性的主要因素，从而为研究大胜关大桥车桥共振机理和确定安全性能预警指标限值提供参考。研究结论：（1）高速列车通过时，主梁振动加速度呈现明显的非平稳振动特性，并且竖向加速度响应明显大于横向加速度响应；（2）大胜关大桥主梁横向和竖向振动均存在明显的共振现象，在150～250km／h的列车车速区间内，列车行驶于中间车道时存在多个共振车速点，而列车行驶于外侧车道时则只有1个共振车速点；（3）监测时间长度和温度变化不会对大胜关大桥车一桥共振特性监测产生影响，通过健康监测系统可以实现对车一桥共振特性的稳定持续监测；（4）本研究结论可为其他大跨钢桁拱桥的车桥共振机理分析提供一定的指导和参考。

Research purposes： As it is known that the long - term vibration of a bridge will directly affect its service status and life, this paper investigated the correlation between the acceleration of girder vibration and the train speeds based on the acceleration data of Dashengguan Bridge from 2014 to 2015. Furthermore, the resonance speed of the girder of the Dashengguan Bridge was explored. The main factors affecting the resonance characteristics of the bridge were analyzed, which offered references to future studies on vehicle -bridge resonance mechanism and identifications of safety alarming system. Research conclusions： （ 1 ） The accelerations of girder vibration have obviously non - stationary characteristics under high- speed trains. Meanwhile, the amplitude of vertical accelerations is evidently larger than the amplitude of transverse accelerations. （2） At the train speed of 150 - 250 kin/h, the bridge girder has obvious resonances in transverse and vertical vibrations. Near the mid - line of bridge, there is multiple resonance speed points while far from the mid -line of bridge, there is only one resonance speed point. （3） The monitoring of resonance characteristics of vehicle - bridge of the Dashengguan Bridge is slightly impacted by the temperature and time of data. So a long - term stable data of health monitoring system can be used for characteristic analysis of vehicle - bridge resonance of the Dashengguan Bridge. （4） The conclusion drawn in this paper can provide certain references to the vehicle -bridge resonance mechanism of other long - span steel - truss arch bridges.