考虑基础沉降的车-桥耦合振动分析

桥梁基础沉降是高速铁路桥梁在运营过程中的主要问题之一,过大的沉降直接影响车辆运行安全性和舒适性。为研究不同桥梁基础沉降形式和沉降量对车-桥耦合振动性能的影响,建立10跨高速铁路32 m典型简支梁桥有限元模型,开展无沉降、单墩沉降、相邻双墩沉降和相邻三墩沉降4种工况的车辆动力响应对比分析。另外,研究10~50 mm内5种沉降量对车辆动力响应的影响。结果表明:对于单墩沉降工况,当沉降量大于20 mm时,随着沉降量的增大车辆竖向加速度明显增大,当沉降量为50 mm时,车辆竖向加速度较无沉降工况增大了1. 2倍;对于相邻双墩沉降工况,车辆动力响应总体上比单墩沉降工况小;相邻三墩沉降对车辆竖向加速度影响显著,当相邻三墩沉降量分别为10,20,30 mm时,车辆竖向加速度比单墩沉降工况更大。研究结果可为确定基础沉降控制限值及线路抬高量提供参考。

Analysis on Vehicle-Bridge Coupling Vibration Considering Foundation Settlement

The settlement of bridge foundation is one of the main problems in the operation of high speed railway bridges,and excessive settlement may directly affect the safety and comfort of vehicle operation.In order to study the influence of different settlement forms and settlement quantitys of bridge foundation on vehicle-bridge coupling vibration performances,a finite element model of 10-span 32 m typical high speed railway simply supported girder bridge was established.The vehicle dynamic responses under four cases were compared and analyzed,including no settlement,single pier settlement,adjacent double-pier settlement and adjacent three-pier settlement. Furthermore,the influence of five settlement quantitys of 10 ~ 50 mm on vehicle dynamic response were studied.The results showthat for the single pier settlement condition,when the settlement quantity is greater than 20 mm,the vertical acceleration increases significantly with the increase of settlement quantity,when the settlement quantity is 50 mm,the vertical acceleration increases by 1. 2 times compared with that of no settlement condition. For the adjacent double-pier settlement condition,the dynamic response of vehicle is generally smaller than that of single pier settlement condition.For the adjacent three-pier settlement condition,the settlement has significant impacts on the vertical acceleration,when the settlement quantity of pier is 10 mm,20 mm and 30 mm,the vertical acceleration is greater than that of the single pier settlement condition.The study results can provide a reference for the limit value of foundation settlement control and line elevation.