板桁结合斜拉桥钢桥面板支撑体系受力分析及构造优化研究

发布时间：2018-08-22 16:53

【摘要】：上承式正交异性钢板桁组合斜拉桥,由于该结构具有自重轻、刚度大、跨越能力强、行车舒适性好的特点,适合用于大跨度山区高速公路的建设,因而在国内外高速公路大跨、特大跨度桥梁和公铁两用桥梁上应用越来越多。而目前在我国现行技术规范中,尚未有针对钢桥面板受力体系设计的细化条款说明,因此需要对板桁组合斜拉桥的板桁受力行为做进一步研究。论文建立了上承式正交异性钢板桁组合斜拉桥的空间有限元模型,对板桁组合体系各主要构造因素对该板桁组合体系的受力行为进行了详细的分析。随后,利用板桁连结系各构件在上横梁位置处的变形协调条件,建立平衡方程,进一步推导出板桁连结系内力分配关系的表达式。同时,针对板桁连结系中,影响横截面传力体系受力行为的条件因素,通过改变相关参数,将各因素对该体系受力行为的影响做客观的定量分析。之后,根据上述研究所得板桁组合体系的受力行为,对其构造进行优化,并通过有限元分析结果对比,验证了该构造优化方法的正确性和可用性。论文研究结果表明,板桁连结系的中纵梁与上弦杆的传力比,与中纵梁、小纵梁、上横梁、次横梁截面刚度呈正比例关系,与上弦杆截面刚度及桥面板横梁布置间距呈反比例;而小纵梁与上弦杆的传力比,与上横梁、次横梁截面刚度呈正比例关系,与上弦杆、中纵梁、小纵梁的截面刚度及桥面板横梁布置间距呈反比例;在考虑有限横梁面外刚度的条件下,利用板桁连结系各杆件在横梁位置处的变形协调条件可建立平衡方程进而推导出每个节段板桁组合结构各构件的纵向荷载传力比,以此传力比为目标进行迭代分析可以有效地对板桁连结系的构造进行优化,并使得全桥板桁组合构件受力更合理,使用效率更高。
[Abstract]:Because of the characteristics of light weight, large stiffness, strong span ability and good driving comfort, the upper bearing orthotropic steel plate truss composite cable-stayed bridge is suitable for the construction of large-span mountain highway, so it is widely used in expressway construction at home and abroad. More and more large-span bridges and dual-purpose bridges are being used. However, in the current technical code of our country, there is no detailed clause for the design of steel bridge face plate stress system, so it is necessary to further study the behavior of slab truss composite cable-stayed bridge. In this paper, the spatial finite element model of orthotropic steel plate truss composite cable-stayed bridge is established, and the main structural factors of the plate truss composite system are analyzed in detail. Then, the equilibrium equation is established by using the deformation coordination condition of each member of the plate truss connection system at the position of the upper beam, and the expression of the internal force distribution relation of the plate truss connection system is derived. At the same time, according to the condition factors that affect the behavior of the cross section force transmission system in the plate truss connection system, the influence of each factor on the stress behavior of the cross section transmission force system is analyzed objectively by changing the relevant parameters. Then, according to the mechanical behavior of the plate truss composite system, the structure of the composite system is optimized, and the validity and availability of the structure optimization method are verified by comparing the results of finite element analysis. The results show that the force transfer ratio of the middle longitudinal beam to the upper chord is proportional to the stiffness of the middle longitudinal beam, the small longitudinal beam, the upper beam and the secondary beam, and the ratio is inversely proportional to the stiffness of the upper chord section and the arrangement of the bridge deck beam. The ratio of transmission force between the small longitudinal beam and the upper chord is proportional to the cross section stiffness of the upper beam and the secondary beam, and is inversely proportional to the section stiffness of the upper chord, the middle longitudinal beam and the small longitudinal beam, as well as the arrangement distance of the bridge deck beam. Under the condition of considering the external stiffness of a finite beam, the balance equation can be established by using the deformation coordination condition of the members of the plate truss connection system at the position of the beam, and the longitudinal load-transfer ratio of each member of each section of the slab-truss composite structure can be derived. Iterative analysis based on this ratio can effectively optimize the structure of plate truss connection system and make the whole bridge plate truss composite members more reasonable and more efficient in use.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U448.27

【相似文献】