主跨457 m钢箱拱桥弹性稳定及极限承载力研究

柳州官塘大桥为主跨457m中承式钢箱拱桥,拱肋采用单箱单室钢箱截面,为拱肋内倾角度10°的提篮式拱桥。为了研究大跨径提篮式钢箱拱桥的稳定特性,采用ANSYS有限元分析软件APDL参数化建模,分析钢材强度、拱肋安装初始缺陷、拱肋内倾角度对主拱弹性稳定和极限承载力的影响。研究表明:随着钢材强度的增大,极限荷载系数逐渐增大,且基本呈线性比例关系;弹性屈曲分析不能反映钢材强度的影响;随着拱肋内倾角度的增大,弹性稳定系数和极限荷载系数呈先增大后降低的趋势,拱肋内倾角度在12°~13°,具有最大的弹性稳定和极限承载力。

Study on Elastic Stability and Ultimate Bearing Capacity of Steel Box Arch Bridge with Main Span 457 m

Liuzhou Guantang Bridge is a half-through steel box arch bridge with main span 457 m.The arch rib adopts the section of single-box single-chamber steel box.This bridge is an X-type arch bridge with angle 100 of arch rib introversion.In order to study the stability characteristics of long-span X-type steel box arch bridge,the ANSYS finite element analysis software APDL parametric modeling is used to analyze the effects of steel strength,initial defects of arch ribs installation and inclination angle of arch ribs on elastic stability and ultimate bearing capacity of the main arch.The study results show that with the increase of steel strength,the limit load coefficient increases gradually,and it is basically linear proportional relationship.Elastic buckling analysis cannot reflect the influence of steel strength.The elastic stability coefficient and the limit load coefficient are increasing and then decreasing with the increase of the angle of arch rib introversion.The angle of arch rib introversion at120 to 130 has the maximum elastic stability and ultimate bearing capacity.