Analysis Of Stability And Arch Foot Stress Field For(25+100+25)m Half-through Composite Beam Tied Arch Bridge With Steel Box Section

The half-through composite beam tied arch bridge with steel box section is a kind of structure with attractive appearance and complex stresses. With the increase of the span as well as the diversity of the cross section, the stability and stress concentration of the structure become a prominent problem. Based on the(25+100+25) m Bayannur Pioneer Bridge as the engineering background, this article conducts the combination method of spatial finite element analysis and local analysis to the whole bridge and the key parts of the arch foot, then systematically research on mechanical behavior of Bayannur Pioneer Bridge. The main items as follows:(1)In this paper, according to structure characteristics of the half-through composite beam tied arch bridge with steel box section, use Midas Civil software to create the space finite element model with the method of Slab Girder. The mechanical force performances of the bridge under dead load and combination of worst-case live load were analyzed. Among them, the suspender cable force adjustment with Midas Civil finite element software incompletion status also have been calculated. Through repeatedly checking and analyzing, the rational completion status are gotten finally.(2)By using Midas Civil software to establish the finite element model of the whole bridge and analyze bridge stability under the effect of various load combination. This paper use constant load, wind load, crowd load and car moving load as variables to calculate, then study the buckling mode and stability coefficient, and study arch rib introversion angle and hang-rod rigidity of these two kinds of different parameters on the influence on the stability of the bridge.(3)Through ANSYS structural analysis finite element program, arch foot local areas are simulated by solid elements. According to the calculation and analysis of stress distribution of the arch foot model under finished bridge state and operation state, this article discusses the stress characteristics of the arch foot and obtains the corresponding stress distribution law. Then an exploratory study is made on the optimization of embedded concrete filled steel box arch rib, in order to obtain the best stress distribution.The main conclusions in this paper can provide references and suggestions in design, construction, stability and the related design analysis of similar bridge structure.