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以润扬大桥斜拉桥为分析对象,提出了扁平钢箱梁结构的多尺度可靠度分析方法。采用子结构方法将扁平钢箱梁整体结构尺度模型和局部构件尺度模型相互衔接,在此基础上采用改进响应面法分析了扁平钢箱梁结构的静力可靠度。分析结果表明:①采用改进响应面法能有效地解决传统响应面法存在的收敛失败和计算误差大的缺点;②采用钢箱梁多尺度模型可以较准确地计算斜拉桥在活荷载作用下的静力可靠指标;③钢箱梁活荷载的分布方式和斜拉桥的几何非线性对斜拉桥静力可靠度具有较大的影响;④采用钢箱梁多尺度模型,可以较真实地研究钢箱梁局部构件损伤对斜拉桥静力可靠度的影响。钢箱梁局部构件损伤对斜拉桥静力可靠指标的影响程度要明显大于对斜拉桥静力特性的影响。因此,在斜拉桥钢箱梁的可靠度设计与状态评估中需要计入结构多尺度效应的影响。
Taking Runyang bridge cable-stayed bridge as the analysis object, a multi-scale reliability analysis method of flat steel box girder structure is proposed. The sub-structure method is used to link the overall structural scale model of the flat steel box girder and the local component scale model to each other. Based on this, the static reliability of the flat steel box girder structure is analyzed by the improved response surface method. The results show that: (1) The improved response surface method can effectively solve the shortcomings of traditional response surface method, such as convergence failure and large calculation error; (2) The multi-scale model of steel box girder can be used to calculate the effect of live load on cable-stayed bridge ; (3) The distribution of live load of steel box girder and the geometric nonlinearity of cable-stayed bridge have a great influence on the static reliability of cable-stayed bridge; (4) The multi-scale model of steel box girder can be more real Study on the Influence of Steel Box Beam Local Parts Damage on Static Reliability of Cable-Stayed Bridge. The effect of local damage to the steel box girder on the static and reliable indexes of cable-stayed bridges is obviously greater than that on the static characteristics of the cable-stayed bridges. Therefore, the reliability of the cable-stayed steel box girder design and status assessment need to be included in the structure of multi-scale effects.