双塔双索面大跨度斜拉桥稳定性分析

Stability Analysis of Double-Span and Double-Cable Long-Span Cable-Stayed Bridge

研究了双塔双索面大跨度斜拉桥稳定性.针对赣江二桥双塔双索面结合梁斜拉桥,考虑结构几何非线性及材料非线性,采用包含梁和索单元的空间组合结构模型,分析了大桥的结构行为,研究了斜拉桥在成桥阶段结构的第一类和第二类稳定性问题.利用ANSYS建立了赣江二桥成桥阶段的整体稳定性分析模型,求解了4种不同工况(恒载+全桥满布活载、恒载+全桥半跨布活载、恒载+中跨布活载以及恒载+全桥满布活载+风荷载)的弹性屈曲系数和第二类稳定的极限承载力.结果表明:赣江二桥成桥阶段的整体稳定性满足要求.

GanJiang No.2 Bridge is a double tower double cable plane reinforced concrete composite beam cablestayed bridge.The long-span cable-stayed bridge is a flexible structure system,and its nonlinearity is mainly embodied in geometric nonlinearity and material nonlinearity.Using the finite element software to analyze the structural behavior of the bridge,the geometric nonlinearity of the structure and the nonlinearity of the material were taken into account in the process of analyzing the composite spatial structure model including the beam and cable elements.The stability of the cable-stayed bridge included the first-class stability and the second-class stability.This paper focused on the first-class stability and the second-class stability of the cable-stayed bridge.In this paper,a model for the overall stability analysis of the bridge of the GanJiang No.2 Bridge was established by ANSYS.When studying the stability of the bridge of the GanJiang No.2 Bridge,the loads were considered as follows：structural weight,deck pavement,cable tension,car and crowd load.In the analysis of the load conditions taking into account the four different conditions,namely,full load＋full bridge full load live load,full load＋full bridge half span fabric live load,dead load＋span fabric live load and full load＋ Bridge full load live load＋ wind load.It can be seen from the analysis that the elastic buckling coefficient and the second kind of stable safety factor of the GanJiang No.2 Bridge in bridge stage meet the requirements in four different working conditions.The results demonstrate that the overall stability of the GanJiang No.2 bridge is satisfactory.In the second type of stability analysis,the second type of stability analysis of the bridge is performed by considering both geometric nonlinearity and double nonlinearity.It can be seen from the analysis that the elastic buckling coefficient under the four different working conditions of the GanJiang No.2 bridge is considered,and the second type of stable safety factor base considering the geometric nonlinearity is considered.Considering the nonlinear second double type stable safety factor meet the requirements of the specification,the results show that the overall stability of the bridging phase inGanJiang No.2 Bridge meets the requirements.