罗蕴河大桥拱脚局部应力分析

Local Stress Analysis of Arch Foot of Luoyun River Bridge

系杆拱桥拱脚应力分析在全桥整体分析过程中属于重点和难点,需在整体模型的基础上建立更高精度的有限元模型进行分析。通过与整体模型的拱脚位移对比,选取结构刚度、边界条件,并制定适当的假定,在MADIS/FEA中建立的拱脚模型。在建立好的模型上施加荷载,进行多方向多尺度的应力分析,最终得出了拱脚应力扩散结论,即混凝土压应力从拱肋传导到拱脚的过程中迅速扩散,在桥梁纵向没有形成很大的压应力峰值,在混凝土抗压强度标准值允许范围之内。对接规范,保证了罗蕴河大桥在拱脚关键部位的安全和可靠。

Stress analysis of arch foot of tied arch bridge is a key and difficult point in the whole analysis process of the bridge.It is necessary to establish a more accurate finite element model on the basis of the whole model.By comparing the displacement of arch foot with the integral model,the structural stiffness,the boundary conditions and the appropriate assumptions are selected,and the arch foot model is established with MADIS/FEA.After apply the load to the model,multi-direction and multi-scale stress analysis is carried out.The conclusion of stress diffusion of arch foot is obtained.The compressive stress of concrete spreads rapidly from arch rib to arch foot,there is no significant compressive stress peak in the longitudinal direction of the bridge,which satisfied with the allowable range of the standard value of compressive strength of concrete.The docking criterion guarantees the safety and reliability of Luoyun River Bridge at the key part of arch foot.