大跨度钢桁拱桥地震需求参数敏感性分析

Analysis on Seismic Demand Parameter Sensitivity of Long-span Steel Truss Arch Bridge

摘要:

大跨度钢桁拱桥常将桥面系与拱肋结合为整体，充分发挥梁承受弯矩，拱肋承受压力的结构特点，愈加广泛地应用于我国桥梁建设中。以某大跨度中承式钢桁拱桥为工程背景，运用一次二阶矩（FOSM）法、Tornado（龙卷风）图表法，分析4种结构地震需求参数对于几种相关不确定因素的敏感度，进而对相关不确定因素的重要性进行排序。分析结果表明：结构的地震需求参数对地震动参数PGA最敏感，其次为结构阻尼和混凝土相关参数，而对其他不确定因素不太敏感，这为同类结构随机地震反应分析以及概率地震需求分析提供了参考依据。

Abstract:

The long-span steel truss arch bridge often combines the bridge deck system with the arch rib as a whole, and gives full play to the structural characteristics of the beam bearing the bending moment and the arch rib bearing the pressure, and is more and more widely used in the construction of bridges in China. Taking a long-span half-through steel truss arch bridge as the engineering background, the FOSM method and Tornado chart method are used to analyze the sensitivity of four structural seismic demand parameters to several related uncertain factors, and then the importance of related uncertain factors is sorted. The analysis results show that the seismic demand parameters of the structure are the most sensitive to the ground motion parameter PGA, followed by the related parameters of structural damping and concrete, and less sensitive to other uncertain factors, which provides a reference for the random seismic response analysis and probabilistic seismic demand analysis of similar structures.