高速列车运行引起的墩顶垂向动反力特征分析

Dynamic Vertical Reaction Force of Piers Caused by Train-bridge Interaction on Elevated High-speed Railway Bridge

结合高速铁路系统特点,钢轨模拟为离散点支撑欧拉梁,桥梁采用模态综合法建立运动方程,在考虑梁轨和轮轨关系基础上建立了车桥动力分析模型,并结合常用跨度简支箱梁特点,分析了轨道不平顺、速度和跨度对墩顶动反力的影响规律.结果表明:中长波范围内轨道不平顺不会对墩顶垂向动反力产生明显影响;随着速度提高,梁的共振和消振造成墩顶动反力的放大和减小;不同跨度简支梁桥墩顶垂向反力特征差异明显,车长和轴距引起的频率都有不同程度体现.

A dynamic interaction model of train and bridge was established considering beam-rail and wheel-rail relation.Based on the characteristics of high-speed railway system,the rail was modeled as a discrete point support Euler beam and the motion equations of the bridge was built using a modal synthesis method.Furthermore,the effect of track irregularity,running speed and beam span on the dynamic reaction force of piers was analyzed with respect to the characteristics of simply-supported box girders in China.It is concluded from the results that the track irregularity with medium and long wavelengths do not have significant effect on the dynamic reaction force of the piers.With increasing running speed,the resonance and vibration cancellation of the beam enlarges and reduces the dynamic reaction force of the piers respectively.The dynamic reaction force characteristics differ significantly under different spans,and different dynamic force frequencies caused by carbody length and wheelbase can be observed at different degrees.