大跨径拱桥缆索施工支架非线性受力特性分析

Nonlinear Analysis of Cable Support for Long Span Concrete Filled Steel Tubular Arch Bridge

随着钢管混凝土拱桥跨径的增大,缆索吊装施工过程中,塔架的受力安全性问题备受关注,但主索的计算为简化的理论计算,不考虑主索滑移及塔架偏位对主索受力的影响,导致塔架受力计算不够精确。以某430 m大跨度钢管混凝土拱桥为例,建立索塔一体化并考虑主索非线性及滑移的有限元模型,考虑塔架偏位对主索及塔架变形与受力的影响,将得到的有限元受力分析结果与现有解析方法的求解结果对比分析,结果表明:有限元方法计算结果偏大,与解析法差距在10%以内,说明考虑主索滑移及塔架偏位时结构受力更不利,此种模拟方式能够较精确地计算主索及塔架的变形及受力特性,为钢管混凝土拱桥的施工提供指导。

With the increase of the span of concrete-filled steel tubular(CFST)arch bridge,the stress and security of the tower in the process of cable hoisting are of great concern,but the simplified calculation of the main cable irrespective of the influence of the slip and deflection of main cable tower cable on the main tower may result in failure to calculate the stress of the tower accurately.Based on the span of 430 m CFST arch bridge,a cable-tower integrative finite element model is established in consideration of the slip of the main cable and this model takes into account the influence of the tower deflection on the main cable and the tower.The comparison between the results obtained by the finite element method and by the analytical method shows that the former is larger in calculation result and the gap between the two methods is less than 10%,which indicates that the structure is more disadvantageous subject to main cable slip and tower deflection.The finite element method can accurately calculate the deformation and the stress of the main cable and tower and provide guidance for the construction of CFST.