拱脚带水平约束弹簧的车辐拱平面内稳定性能

针对非落地拱承受竖向荷载作用时拱脚水平约束刚度不足会产生水平位移,导致拱脚的受力性能和承载能力发生较大变化的问题,采用ANSYS有限元软件建立拱脚带水平约束弹簧的模无索拱和车辐拱有限元模型。采用数值分析方法分别对无索拱和车辐拱在全跨竖向均布荷载和半跨竖向均布荷载进行一阶弹性和弹塑性分析,研究其拱脚水平弹簧刚度幅值变化对车辐拱受力性能的影响,包括拱脚水平推力和位移的变化、沿拱轴线内力变化和分布以及平面内稳定承载性能等。结果表明:车辐拱中的拉索可以有效约束拱脚的水平位移和减小水平推力,显著提高拱整体刚度和稳定承载力; 车辐拱中的拉索可以有效限制拱脚弹簧刚度幅值的下降对车辐拱内力分布及稳定承载性能的影响; 研究成果为非落地车辐拱及拱脚支承构件的设计提供了依据。

In-plane Stability of Cable-arches with Horizontal Restraining Spring at Foot of Arch

In practical engineering, the horizontal displacement would occur due to the insufficient rigidity of the horizontal restraint at the feet of the non-grounded arch subjected to the vertical load. In the view of the problem that horizontal displacement at the arch feet would significantly change the mechanical performance and load-carrying capacity of the arch, the finite element model of the conventional arch and the spoke arch with the horizontal restraining spring at the arch foot was established by using ANSYS finite element software. The full span distributed vertical load and half span distributed vertical load were discussed in the numerical analyzing. The first-order and the inelastic analysis were carried out to investigate the influence of the spring stiffness amplitude on the mechanical properties of the conventional arch and the spoke arch, including the changes of the horizontal thrust and displacement of the arch foot, the changes of the internal force along the axis of the arch and the in-plane stability performance. The results show that cables in the spoke arch can significantly reduce the horizontal displacement and the horizontal thrust of the arch feet, significantly improve the overall stiffness and the load-carrying efficiency over the conventional arch. Moreover, cables in the spoke arch can significantly limit the influence of the decrease in the spring stiffness amplitude on the internal forces and the stability performance of the spoke arch. These conclusions provide fundamentals for the strength design of the spoke arches and the supporting components of the arch feet.