桥上无缝线路温度跨度的极值影响因素分析

为科学合理地确定不设钢轨伸缩调节器的桥梁温度跨度，通过建立线桥墩一体化计算模型，研究各种因素对有砟桥上无缝线路最大温度跨度的影响。研究结果表明：钢轨顶面垂磨增大，最大温度跨度逐渐减小；墩顶纵向水平位移增大，最大温度跨度与墩顶位移近似成等比例减少；制动力对钢轨升温幅度较大时的最大温度跨度有一定影响；大机维修所确定的温度跨度要比大机清筛的小；为减缓地震对桥梁纵移、横移的影响，高速铁路桥梁设计中应采用防落梁装置。综合分析后，考虑了轨温变化幅度、墩高2个影响因素，得出了桥梁温度跨度极值的建议值，如最大墩高小于30m，轨温变化幅度分别为30，40和50℃时，温度跨度极值分别建议为320，300和280m。

Analysis of influence factors on the extreme temperature span of CWR on bridge

In order to determine the reasonable scientific bridge temperature span without setting the RE J, the effects of various factors on the maximum temperature span bridge were discussed through establishing a line - bridge -pier integration model for calculation of CWR on bridge. The calculation results show that with the in- crease of the rail top vertical wear, the maximum temperature span decreases gradually. When the displacement of pier top longitudinal level increases, the maximum temperature span and pier top displacement approximately proportional reduce. When the rail temperature amplitude is relatively large, braking force has some influences on the determination of maximum temperature span, and temperature span of large machine repair is less than that of big machine cleaning. In order to mitigate the effects of earthquake on the bridge longitudinal and trans- verse displacement, beam falling prevention device should be used in the design of high speed railway bridge. After the comprehensive analysis, the two impact factors of the rail temperature variation amplitude, high pier were taken into account so as to derive the recommended values of extreme temperature span, for instace, if the maximum pier height is less than 30 m, and the track temperature variation is 30,40 and 50 ℃, the extreme temperature span recommended values are 320,300 and 280 m