| 引用本文: | 王泳金,任伟新,秦李冯.山区大跨度钢桁梁斜拉桥极限承载力分析[J].哈尔滨工业大学学报,2023,55(11):1.DOI:10.11918/202304015 |
| WANG Yongjin,REN Weixin,QIN Lifeng.Ultimate load carrying capacity analysis of long-span steel truss girder cabled-stayed bridge in mountainous area[J].Journal of Harbin Institute of Technology,2023,55(11):1.DOI:10.11918/202304015 |
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| 摘要: |
| 山区大跨度斜拉桥结构组成复杂,在活载作用下整体结构的静力行为呈现明显的非线性,结构稳定问题突出,为此,以主跨为930 m在建的云南山区大跨度钢桁梁斜拉桥为背景,基于极值点失稳理论,考虑结构几何与材料双重非线性,进行稳定极限承载力分析,研究大桥在活载作用下的非线性行为和失效机制。鉴于山区风存在明显的“峡谷效应”,桥梁在施工中易受风荷载的影响,进行了最大悬臂施工状态的静风荷载的极限承载力分析。结果表明:几何非线性效应对结构性能的影响较材料非线性要小,大跨度斜拉桥整体的极限承载力由斜拉索的材料破坏控制；随着活荷载的增加,主梁弹塑性区逐渐发展,先后出现了受拉、受压塑性区,形成了4条屈服路径；在结构最大悬臂施工状态下,计算获得的桥梁横向静力极限承载力远大于十二级风速时对应的静风荷载。 |
| 关键词: 斜拉桥 非线性 结构稳定 极限承载力 失效机制 |
| DOI：10.11918/202304015 |
| 分类号:U448.14 |
| 文献标识码:A |
| 基金项目:深圳市科技创新委员会项目(JSGG20210802093207022,GJHZ20200731095802007,KQTD20180412181337494) |
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| Ultimate load carrying capacity analysis of long-span steel truss girder cabled-stayed bridge in mountainous area |
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WANG Yongjin,REN Weixin,QIN Lifeng
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(College of Civil and Traffic Engineering, Shenzhen University, Shenzhen 518061, Guangdong, China)
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| Abstract: |
| The structural composition of long-span cable-stayed bridges in mountainous area is complex. As the static behavior of the whole structure under live loads presents obvious nonlinearities, the structural stability problem is prominent. Therefore,based on a steel truss girder cable-stayed bridge with a main span of 930 m under construction in the south mountainous area of Yunnan Province, China, the ultimate load carrying capacity analysis is carried out by using limit point instability theory where both structural geometric and material nonlinearities are considered. It is aimed at investigating the nonlinear behavior and failure mechanism of such a long-span bridge under live loading. Because of the existence of “canyon effect” for the wind in the mountainous area, the bridge is easy to be affected by wind loads during construction. Subsequently, the ultimate load carrying capacity analysis of the bridge at the maximum cantilever construction state is performed under static wind loading. The results have shown that the geometric nonlinearity has less influence on the structural performance than the material nonlinearity does. The ultimate load carrying capacity of the long-span cable-stayed bridge is controlled by the material failure of the cable. With the increase in live load, the elastic-plastic zones develop gradually. The tensile and compressive plastic zones appear successively on the steel truss girder, forming four yield paths. At the maximum cantilever construction stage, the calculated ultimate load capacity is greater than static wind load of Grade 12 wind speed. |
| Key words: cable-stayed bridge nonlinearity structural stability ultimate load carrying capacity failure mechanism |
