摘要
为研究铁路网状体系拱桥的结构受力性能,以某主跨160 m双线铁路网状体系拱桥为研究背景,采用有限元方法,建立桥梁结构的三维空间仿真分析模型,对比吊杆根数、吊杆倾角、拱肋倾角和矢跨比4种设计参数对桥梁静力性能的影响,讨论结构位移、轴力、弯矩、应力等响应的变化规律。结果表明:吊杆根数的增大能减小活载引起的桥梁竖向位移,但拱圈压应力有所增大;桥梁的最大拉应力和最大压应力均随着吊杆倾角的减小而增大,最大压应力出现在拱肋拱脚位置,吊杆倾角为40°和50°时,吊杆所受拉应力大于钢材容许应力,吊杆倾角大于50°时,梁端短吊杆受压;随着拱肋倾角增大,拱桥拉应力近乎线性增大,压应力有所减小;矢跨比越大,活载作用下跨中挠度越小,桥梁最大轴力和弯矩有一定程度减小,吊杆受到的拉应力也越大,矢跨比为0.14~0.20时,拱桥最小应力绝对值随着矢跨比的增大而减小,而当矢跨比从0.20增大至0.22时,最小应力绝对值则显著增大。
To study the structural mechanical performance of railway network arch bridges,this study focuses on a 160 m main span double-track railway network arch bridge.Using the finite element method,a three-dimensional spatial simulation analysis model of the bridge structure was established.The study examined the effects of four design parameters,including number of suspenders,suspender inclination angle,arch rib inclination angle,and span-to-rise ratio,on the bridge's static performance.The changes in structural displacement,axial force,bending moment,and stress responses were discussed.The results showed that increasing the number of suspenders reduced vertical displacement of the bridge caused by live loads,but compressive stress in the arch ring increased.Both the maximum tensile and compressive stresses of the bridge increased as the suspender inclination angle decreased,with the maximum compressive stress occurring at the arch rib foot.When the suspender inclination angles were 40°and 50°,the tensile stress on the suspender exceeded the allowable stress of the steel,and the short suspenders at the beam ends experienced compression when the suspender inclination angle exceeded 50°.As the arch rib inclination angle increased,the tensile stress in the arch bridge increased almost linearly,while the compressive stress decreased slightly.As the span-to-rise ratio increased,the mid-span deflection under live load decreased,the maximum axial force and bending moment of the bridge was reduced to some extent,and the tensile stress on suspenders increased.When the span-to-rise ratio ranged from 0.14 to 0.20,the absolute value of the minimum stress in the arch bridge decreased with an increasing span-to-rise ratio.However,when the span-to-rise ratio increased from 0.20 to 0.22,the absolute value of the minimum stress increased significantly.
作者
宋晓东
熊佳
杨超
SONG Xiaodong;XIONG Jia;YANG Chao(China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China)
出处
《铁道标准设计》
北大核心
2024年第9期82-88,共7页
Railway Standard Design
基金
国家重点研发计划项目(2021YFB3704403)。
关键词
铁路桥梁
网状拱桥
静力性能
数值计算
设计参数
有限元分析
railway bridge
network arch bridge
static performance
numerical calculation
design parameter
finite element analysis
