【摘要】 铁路拱桥桥面过大变形将危及列车行驶和桥梁结构的安全,但已有关于拱桥变形限值标准及评判依据的研究较为少见。以某上承式拱桥为研究对象,建立桥梁全桥有限元模型并进行车桥耦合振动分析,研究温度及不同倍数徐变引起的桥面变形对列车动力响应的影响,对比分析弦测法弦长与列车在轨道和上承式拱桥上运行的动力响应间的对应关系。结果表明:仅考虑轨道不平顺激励时,30～50 m弦测法能够较好地反映高速列车的加速度响应的变化规律;上承式拱桥徐变倍数为1.6时,车辆竖向加速度响应超限;仅轨道不平顺作用下列车竖向加速度卓越频率约为1 Hz,运行在上承式拱桥上时的卓越频率在1～2 Hz,说明影响振动的波长范围由长波向中长波扩展;弦测法用于上承式拱桥时,采用20～30 m弦长;上承式拱桥温度及徐变极限变形20,25,30 m弦测矢量值为3.8,4.3,5.3 mm,对应的限值可采用3.5,4.0,5.0 mm。更多还原

【Abstract】 Excessive deformation of the bridge surface of the railway arch bridge will endanger the safety of the train and the bridge. However, the research is relatively scarce about the limit standards and judgment basis of the deck deformation for railway arch bridges. A deck arch bridge was taken as the research object, the full model of this bridge was established, and then the vehicle-bridge coupling vibration analysis was performed. The influence of the bridge deck deformation caused by temperature and different times creep on the dynamic responses of the vehicle was then investigated, and the correspondence between the chord length of the chord measurement method and the dynamic responses of the vehicle running on the track and the deck arch bridge was comparative analyzed. The results show that the variation law of the acceleration response of the high-speed vehicle can be reflected accurately through the 30～50 m chord measurement method when only the track irregularity excitation is considered. When the creep ratio of this deck arch bridge is 1.6, the vertical acceleration response of the vehicle exceeds the response limit. The predominant frequency of the vertical acceleration of the vehicle is 1 Hz only under the effect of the track irregularity, and that of the vehicle running on the deck arch bridge increases to 1～2 Hz, indicating that the range of wavelengths affecting vibration extends from long-wavelength to medium-long-wavelength. Chord length from 20 m to 30 m is more suitable in chord measurement method for deck arch bridges. The 20 m, 25 m and 30 m chord vector value of the temperature and creep ultimate deformation for deck arch bridges is 3.8 mm, 4.3 mm and 5.3 mm, and the corresponding chord limit can be determined as 3.5 mm, 4.0 mm and 5 mm, respectively.更多还原