高墩大跨铁路连续刚构桥动力特性分析研究

Research on the Dynamic Characteristics of High-pier and Large-span Railway Continuous Rigid Frame Bridge

研究目的:随着列车提速及高速、重载铁路的发展,车桥动力相互作用、桥梁抗振等桥梁结构的动力问题日益突出,本文以渝黔铁路朝门乌江大桥(92+168+92)m预应力混凝土连续刚构为工程背景,对该桥的动力问题包括自振特性、地震反应谱、车桥耦合动力进行分析研究,对该桥在动力作用下运营的安全性、舒适性进行分析、评价,从而为该桥的动力结构设计提供依据。研究结论:(1)结构自振特性计算分析中,桩土作用和边墩作用对结构整体刚度有一定影响,计算分析中应注意模拟;(2)当连续刚构主墩较高时,横向刚度较难满足,可以考虑主墩墩身采用二次变坡,可以明显提高结构的横向刚度,优化质量分布,使结构横向刚度满足要求;(3)高墩大跨结构应进行车桥耦合振动分析,综合考虑列车-线路-结构间的共同作用,确保车辆运行的安全性及舒适性;(4)该研究成果可为同类高墩大跨铁路连续刚构桥的动力分析提供指导和借鉴。

Research purposes： With the development of the train speed and the high speed and heavy haul railway, train bridge interaction, bridge seismic and other bridge dynamic structure is becoming increasingly prominent, the Chongqing -Guizhou railway Chaomen Wujiang bridge （92 ＋ 168 ＋ 92） m Prestressed Concrete Continuous Rigid Frame Bridge as the engineering background, the dynamic problems including self vibration characteristics, seismic response spectrum, the vehicle bridge coupling are analyzed, the safety and comfort of the bridge are analyzed and evaluated, which provide the basis for the design of the dynamic structure of the bridge. Research conclusions： （ 1 ） In the calculation and analysis of the structure of the structure, the effect of pile soil and the side pier has some effect on the overall stiffness of the structure. （2） When the main pier continuous rigid frame is high, the lateral stiffness is difficult to meet, the main piers with two variable slope can be considered, which can significantly improve the lateral stiffness of the structure, optimize the quality of distribution, and make the structure lateral stiffness meet the requirements of the railway. （ 3 ） High pier and long - span structures should be analysis of coupling vibration of vehicle bridge, considering interaction of train track structure, ensure vehicle running safety and comfort. （4） The research results can provide guidance and reference for the dynamic analysis of similar high pier and long span railway continuous rigid frame bridge.