简支梁桥上无缝道岔纵向力影响因素分析

Analysis of Factors Influencing Longitudinal Force of Welded Turnout on Simply Supported Beam Bridge

根据桥上无缝道岔纵向相互作用的特点,建立了道岔-桥梁-墩台一体化有限元计算模型,以18号道岔铺设在简支梁桥上为例,分析了钢轨温度、桥梁温度、桥梁跨度、支座布置形式、墩台刚度、辙跟传力部件结构及阻力参数等对简支梁桥上无缝道岔受力与变形的影响.计算结果表明,简支梁桥上的无缝道岔对线路和桥梁的影响范围仅限于与道岔相邻的2孔梁以内;应采用道岔里轨与简支梁伸缩位移方向相反的桥上无缝道岔布置方式;应适当增大道岔范围内桥墩的纵向刚度;桥上无缝道岔辙跟不宜采用间隔铁结构;18号道岔宜铺设在跨度32或48 m的简支梁桥上.

Based on the characteristic of longitudinal interaction of welded turnout on a bridge, a finite element model for welded turnout-bridge-platform was established. By taking No. 18 welded turnout on a simply supported beam bridge as an example, factors influencing its longitudinal force and displacement were analyzed. These factors are the temperature of rail, the temperature of bridge, the length of beam, the layout of support, the stiffness of pier, the structure of frog heel, and the resistance of fastening and ballast. Calculational results show that the influence range of welded turnout on a simply supported beam bridge was within two spans. The arrangement of welded turnout on simply supported beam bridges should make the expansion displacement directions of the turnout lead rail and the beam be opposite. The longitudinal stiffness of piers under welded turnout should be increased, and spacer block should not be adopted as the frog heel of welded turnout on a simply supported beam bridge. The No. 18 welded turnout is suitable for laying on a simply supported beam bridge with a span of 32 or 48 m.