曲线钢-混组合箱梁桥车桥耦合振动及支座受力研究

Study on vehicle bridge coupled vibration and support reaction force of curved steel-concrete composite box girder bridge

曲线钢-混组合箱梁桥已经建设较多,在设计中因对其车桥耦合振动认识有限,相关支座反力因弯扭耦合效应引起的变化情况等尚未很好解决。基于ABAQUS有限元软件,利用傅里叶级数描述车辆平、竖曲线运动,实现了曲线梁桥车桥耦合振动的数值分析,并基于既有试验和理论成果验证了方法的准确性。以某4跨曲线钢-混组合箱梁桥为例,分析了车辆在内、外侧车道以不同速度行驶及超高条件下对桥梁支座反力的影响。结果表明:当车辆沿着曲线梁桥内侧或外侧车道行驶时,另一侧箱梁的外支座会出现脱空的现象。车速对支座峰值反力的影响较小,但可以通过较低的车速减轻支座脱空。超高对支座反力的影响较小,车辆沿着内侧车道行驶时,缓解了外侧箱梁部分支座脱空;沿着外侧车道行驶时,加重了内侧箱梁支座脱空。

Many steel-concrete composite curved box girder bridges have been built recently,while in these bridge designs,the understanding of vehicle-bridge coupled vibration was limited.Due to the effect of bending-torsion coupled under vertical loading,the change of the reaction force of the relevant support bearing has not been well solved.In this paper,based on the ABAQUS general finite element software,the horizontal curved motion of the vehicle was simulated by the method of Fourier series,which made the numerical analysis of vehicle bridge coupled vibration be possible.The numerical analysis results had verified for its accuracy with the existing experimental and theoretical ones.Taking a steel-concrete composite box girder bridge with four spans as an example,further analysis were carried out considering the influence of the support bearing force of bridge under the case of vehicle on the inside and outside lanes and superelevation.The results indicate that the outer support bearing of the other side of the box girder will appear falling,when the vehicle is driving along the inside or outside lanes of the curved girder bridge.The vehicle speed has little influence on the peak support bearing force,while the bearing separation can be alleviated by the lower vehicle speed.The superelevation has little effect on the support bearing reaction force.When the vehicle is driving along the inside lane,it will be easy to alleviate the falling of some support bearings of the outside box girder.When it is driving along the outside lane,it will aggravate the bearing separation of the inside box girder.