系杆拱连续梁桥-多线轨道互制分析的荷载步法

Step-by-step Loading Analysis of Interaction between Tied Arch Continuous Bridge and Multi-line Track

为研究考虑加载历史的桥梁-多线轨道系统受力特性,通过推导考虑加载历史的线路纵向阻力迭代公式并以某(77+3×156.8+77)m系杆拱连续梁桥为例,建立考虑钢管混凝土拱、吊杆、梁体、桥墩、桩基、多线轨道的大跨度系杆拱连续梁桥一体化有限元模型,分析加载历史对系杆拱连续梁桥-轨道系统受力影响及结构检算结果。结果表明:代数求和算法计算钢轨应力峰值偏大61.9%,墩顶水平力偏大74.0%,考虑温度效应须同时对钢轨、梁体和拱施加温度荷载;挠曲工况下双线同向加载时墩顶水平力为1058.2 kN,双线对向加载时墩顶扭矩为4193.6 kN·m;计算温度制挠力时,代数求和算法计算钢轨应力较荷载步法偏大7%,墩顶水平力偏大8%~27%,设计不经济;代数求和算法计算墩顶扭矩与荷载步法最大偏差可达51.3%。

In order to explore the mechanical characteristics of bridge-multiline track system considering loading history,the iterative formula for line longitudinal resistance considering loading history is derived in the case of a(77+3×156.8+77)m tied arch continuous bridge,and the integrated model of long-span tied arch continuous bridge is established in view of concrete filled steel tube arch,suspender,beam,pier,foundation and multiline track,so as to analyze the effects of loading history on tied arch continuous bridge-track system.The results show that compared with the step-by-step analysis,the peak stress of rail calculated by algebraic summation algorithm is 61.9%larger,and the horizontal force on the pier top is 74.0%larger;temperature loads should be simultaneously applied to the rail,beam and arch under temperature effect.Under the flexure load,the pier-top force under double-line same direction load could be 1058.2 kN,and the pier-top torque under double-line face-to-face load could be 4193.6 kN·m.When calculating the braking and bending force under temperature load,rail stress calculated by algebraic summation algorithm is about 7%larger than that by the step-by-step analysis,and the pier-top force is 8%~27%larger,which is uneconomical in design.The maximum pier-top torque calculated by algebraic summation algorithm could be 51.3%larger that of the step-by-step analysis.