顺置式吊杆锚固区受力特性与极限承载力研究

为掌握顺桥向设置的吊杆锚固区在吊杆力作用下的受力特性和极限承载力,以某在建斜拉-自锚式悬索组合体系桥为依托工程,利用ANSYS软件建立壳单元空间有限元模型,对锚固区在最不利荷载作用下的受力性能进行研究;并分别采用线弹性及非线性分析方法对吊杆锚固区极限承载力进行分析,讨论构件的受力情况。结果表明:在最不利荷载作用下,钢锚箱及钢锚梁应力较横隔板应力小;除钢锚梁与横隔板焊接处应力集中现象显著外,各构件应力分布较均匀;各构件顺桥向变形较大。不同极限承载力分析方法表明,此类结构采用壳单元建模进行极限承载力分析时应仅考虑材料非线性。建议在此类结构设计时,对于横隔板刚度不足问题应给予足够重视。

Study of Mechanical Behavior and Ultimate Carrying Capacity of Suspender Anchorage Zone in Axial Direction of Bridge

To have an understanding of the mechanical behavior and ultimate carrying capacity of suspender anchorage zone set in the axial direction of bridge under the action of suspender forces,a combined cable-stayed and self-anchored suspension system bridge that was being constructed was cited as an example,the software ANSYS was used to set up the spatial shell finite element model,the mechanical behavior of the anchorage zone under the action of the worst load was studied,the ultimate carrying capacity of the anchorage zone was analyzed,respectively using the linear elasticity and nonlinearity analysis methods and the force conditions of the components in the anchorage zone were discussed.The results of the study show that under the action of the worst load,the stress in the steel anchor box and steel anchor beam is less than that in the diaphragm.With the exception that the stress concentration in the welding of the steel anchor beam and diaphragm is notable,the stress distribution in all components is uniform and the deformation of the components in the axial direction of the bridge is great.The results of the different analysis methods for the ultimate carrying capacity also show that when the ultimate carrying capacity of such type of the structure is analyzed,using the shell element model,the material nonlinearity should considered only and in the design of the structure,it is proposed that adequate attention should be paid to the problem of insufficient rigidity of the diaphragm.