设置反拱加固的拱结构力学性能研究

Mechanical performance of arch structure with anti arch reinforcement

提出了一种设置反拱结构的拱桥加固方法,该方法是通过在主拱圈拱肋下方设置反拱,在反拱和拱肋之间用竖杆相连,并通过抗弯预埋件和抗剪锚栓把反拱的拱脚和拱肋连接,使反拱结构和原主拱圈共同形成结构受力体系。本文基于有限元参数分析方法,通过设置6个不同参数:拱的矢高f1、拱的拱轴系数m1、反拱的矢高f2、反拱的拱轴系数m2、反拱与待加固拱的等效半径比i、反拱纵向长度与待加固拱的总跨径的比值Kr,以考虑不同拱桥、反拱结构参数对原拱桥关键截面内力、跨中挠度及整体屈曲系数的影响。基于大量计算数据的参数拟合,分别获得跨中弯矩、跨中挠度、拱脚弯矩、拱脚推力、整体屈曲系数的拟合表达式。通过对拟合数据的分析,获得了反拱加固的拱桥结构力学特性的相关变化规律。最后对一个100m跨径拱桥进行加固计算分析,结果表明:本文提出的加固方法不但可以显著提高待加固桥梁的整体刚度与稳定性,而且可有效地降低主拱关键截面的内力。

Arch Structures with anti arch reinforcement is presented in this paper,an anti arch rib is arranged below the main arch,between the anti arch and the main arch rib,a vertical rod is arranged to connect each other,which to make the former arch and reinforce arch structure become a common force system.The finite element analysis method is carried on based on the parameters.The parameters includes main arch rise high f1,arch axis coefficient m1,anti arch height f2,arch axis coefficient m2,ratio of anti arch and arch reinforcement equivalent radius i and longitudinal length ratio of reinforce arch Kr.Different parameters are set to consider how different arch bridgestructures and arch structure parameters affect the original arch bridge key section internal forces,deflections and buckling coefficients,and the parameters are fitted to several expressions.Based on the analysis of the fitted data,the relative regularity of the structural mechanical characteristics of the arch bridge strengthened with inverted arch are obtained.Also a case of 100 m arch bridge is analyzed,results show that the proposed method increases the overall rigidity and stability of the bridge,and also effectively reduces the internal force of the key section of the main arch.