拱墩降温对大跨桥上连续式无砟轨道竖向位移影响分析

Analysis of Vertical Displacement Effect on Continuous Ballastless Track on Large-span Bridge due to Temperature Reduction of Arch and Pier

受季节和日照的影响,高墩大跨拱桥混凝土结构会出现膨胀现象,从而引起桥墩顶部竖向位移的变化。为了研究拱墩降温对高墩大跨拱桥上连续式无砟轨道竖向位移和高低不平顺的影响,根据桥上连续式无砟轨道的结构和受力特征,参考国内某大跨度上承式钢筋混凝土拱桥的实际参数,利用有限元方法,建立线-桥-墩一体化模型,分析拱墩降温对大跨拱桥上连续式无砟轨道的竖向位移和高低不平顺的影响。结果表明:拱墩降温引起的大跨桥上线路竖向位移较明显,设计时不可忽略;拱墩降温会引起线路高低不平顺,且对长波不平顺影响最严重;线路高低不平顺随降温幅度增加而增大,在年温差较大的地区目前不建议高墩大跨拱桥与连续式无砟轨道配合设计使用。

Due to the influence of season and sunshine,the expansion of the concrete structure of large-span arch bridge with high pier will result in the vertical displacement at the top of the pier. In order to analyze the effect of the vertical displacement and vertical irregularity on continuous ballastless track on large-span arch bridge with high pier due to temperature reduction of arch and pier,a line-bridge-pier integration model is built and the finite element method is used to analyze the effect of the vertical displacement and vertical irregularity on continuous ballastless track on large-span arch bridge due to temperature reduction of arch and pier according to the structure and force characteristics of continuous ballastless track on bridge and referring to the actual parameters of a domestic deck type large-span reinforced concrete arch bridge. The results show that the vertical displacement of the large-span bridge caused by the temperature reduction of arch and pier is considerably obvious and can＇t be ignored in the design; the temperature reduction of arch and pier will cause vertical track irregularity,and the effect on long wave irregularity is most serious; the vertical track irregularity increases with the increase of the cooling range,and for the time being,it is not recommended to use large-span arch bridge of high pier together with continuous ballastless track in areas with large annual temperature difference.