摘要
为研究构件损伤对斜拉桥结构静力性能的影响,以合江长江二桥为原型,基于相似比理论和刚度相似原理,设计缩尺比为1/40的斜拉桥节段模型。建立原型桥和模型桥的有限元模型,对其进行静力相似对比分析。对8组拉索断裂工况和12组主梁损伤工况下的斜拉桥模型进行试验,研究不同损伤工况下拉索索力、主梁应力和挠度的分布规律,揭示拉索失效和主梁损伤对斜拉桥静力性能退化的影响。试验结果表明:本模型斜拉桥能较好地反映实际原型桥的受力状况;拉索断裂改变了主梁的边界支承条件,主梁损伤削弱了钢主梁截面抗弯惯性矩和刚度,是斜拉桥性能退化的主要原因之一;跨中断索后引起的拉索索力、主梁应力和挠度增幅均较大,靠近边墩的主梁区域对全桥索力和主梁应力有重要调控作用,应提高跨中拉索的安全系数,增强边墩区域主梁的承载力储备,优化混凝土抗裂性设计;荷载对损伤主梁的刚度退化作用显著,对服役较长时间的斜拉桥应限制车流量和车辆载荷。
To study the effect of component damage on the structural static performance of cable-stayed bridge,the second Hejiang Yangtze River Bridge was used as a prototype and a segment model of cable-stayed bridge with a scale ratio of 1/40 was designed based on the similarity ratio theory and the stiffness similarity principle.The finite element model of the prototype bridge and the model bridge was established,and the static similarity analysis was carried out.The model tests of cable-stayed bridge under 8 groups of cable rupture and 12 groups of damaged main girder conditions were performed.The distribution of cable force,main girder stress and deflection under different damage conditions were studied.The influencs of cable failure and main girder damage on the static performance degradation of cable-stayed bridges were revealed.The results show that the cable-stayed bridge model can reflect the actual force status of the prototype bridge.The failure cables change the boundary support conditions of the main girder,and the damage of the main girder weakens the section bending moment of inertia and rigidity of the steel main girder,which is one of the main reasons for the performance degradation of the cable-stayed bridge.The cable force,main girder stress and deflection caused by the cable rupture in the middle span increase.The main girder area which is close to the side piers plays an important role in regulating the cable force and main girder stress of the whole bridge.It is suggested to increase the safety coefficient of the midspan cable and the bearing capacity which reserves the main girder in the side pier area,the concrete crack resistance design is optimized.Load has significant effects on the stiffness degradation of the damaged main beam.For a cable-stayed bridge that has been in service for a long time,traffic flow and vehicle load should be restricted.
作者
马亚飞
彭安银
王磊
张建仁
MA Yafei;PENG Anyin;WANG Lei;ZHANG Jianren(School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2022年第2期653-664,共12页
Journal of Central South University:Science and Technology
基金
国家重点基础研究发展计划(973计划)项目(2015CB057705)
国家自然科学基金资助项目(51778068)
湖南省研究生科研创新项目(CX20190672)。
关键词
斜拉桥
拉索断裂
主梁损伤
静力性能
模型试验
cable-stayed bridge
cable fracture
main girder damage
static performance
model test
