异形斜杆三连拱桥受力性能及稳定性分析

The Mechanical Performance and the Stability Analysis of the Three Span Continuous Special Shape Arch Bridge with Inclined Booms

异形斜杆拱桥在设计阶段结构参数均为理想值,施工过程中,施工机械以及材料堆积会对主梁及拱肋等产生荷载作用,运营过程中,钢材的弹性模量会受到温度和周围介质的影响及自身因素的影响发生变化,为全面了解异形斜杆拱桥结构的受力特点,需要在结构参数变化时,对其力学性能的变化规律进行一定的分析和了解。以陕西某特大桥主桥设计方案为背景,借助有限元计算软件Midas/Civil建立了该桥空间有限元模型,研究了异形斜杆三连拱桥主梁及拱肋在不同结构参数下对主梁位移、主拱肋轴力、吊杆索力等的影响,同时分析了在成桥状态下仅有恒载作用时,主拱肋外倾角分别为0°、8°、16°、24°共4种工况下的该桥第1类稳定问题,证明了主拱肋外倾角度选择的合理性,为以后同类桥梁的设计、施工及后期检测提供参考。

The structure parameters of the special shape arch bridge with inclined booms during the design phase are the ideal value. Construction machinery and material accumulation will load effect on the main girder and arch rib during the construction process. At the same time,the elastic modulus of steel will be affected by the influence of temperature and the surrounding medium in the process of operation. We need to analysis and understand the change rule of the mechanical properties when the structure parameters change for a comprehensive understanding of the mechanical characteristics of the special shape arch bridge with inclined booms. This paper is based on the design proposal of a super major bridge in Shanxi province. The girder and arch rib of the three span continuous arch bridge with inclined booms is studied under different structure parameters of main girder displacement and axial force of the main arch rib,derrick cable force with the aid of finite element software Midas / Civil to establish the bridge space finite element model. At the same time,the force conditions of various parts of the bridge under the four cases that the camber angles of the main arch ribs were respectively 0°,8°,16° and 24° under the action of only dead load were calculated and the Category 1 Stability issue of the bridge in completion state was analyzed,proving the rationality of selecting the main arch rib extraversion angle. This paper can provide reference for future design,construction and detection of similar bridges.