长联大跨部分斜拉桥上无砟轨道平顺性分析

Analysis of Smoothness of Ballastless Track on Long-span Partial Cable-stayed Bridge

研究目的:为探究长联大跨部分斜拉桥平顺性影响因素,以长青黄河特大桥为对象,考虑列车荷载、主梁主塔整体升温、斜拉索升温和主梁垂向温度梯度外部荷载因素,建立非线性静力学仿真模型,分析这些因素对大跨连续梁上无砟轨道的影响,并基于60 m弦测法,分析这些影响因素组合时对轨道高低不平顺幅值的影响。研究结论:(1)桥塔升温和斜拉索降温会降低列车荷载作用下轨道不平顺幅值;(2)日照温差(沿梁高方向)、塔梁日温差与梁索温差对轨道高低不平顺的影响系数分别为0.34 mm/℃、0.18 mm/℃、0.13 mm/℃;(3)拟合了包含列车荷载、主梁主塔整体升温、斜拉索升温和主梁垂向温度梯度多工况控制作用下的轨道高低不平顺幅值计算公式;(4)本研究结论可为超长长联大跨部分斜拉桥上铺设无砟轨道平顺性研究提供参考。

Research purposes:In order to investigate the influence factors on the smoothness of long and large-span partial cable-stayed bridges,the Changqing Yellow River Super-large Bridge is used as the object,and the external load factors of train load,overall warming of the main girder main tower,warming of the stayed cable and vertical temperature gradient of the main girder are considered,and a nonlinear static simulation model is established to analyze the influence of these factors on the ballastless track on large-span continuous girders,and based on the 60 m string measurement method,the influence of the combination of these factors on the amplitude of track unsmoothness is analyzed.Research conclusions:(1)Tower warming and cable cooling will reduce the amplitude of track unsmoothness under train load.(2)The coefficients of daylight temperature difference(along the girder height direction),tower and girder daily temperature difference and girder and cable temperature difference on track unsmoothness are 0.34 mm/℃,0.18 mm/℃and 0.13 mm/℃,respectively.(3)The formulae for the calculation of track unsmoothness amplitude under the effect of multiple working conditions including train load,main girder tower warming,stayed cable warming and main girder vertical temperature gradient are fitted.(4)The research results can provide reference for the research on the smoothness of ballastless track laid on super-long and long-span partial cable-stayed bridge.