Stability Analysis Of Concrete Filled Steel Tubular Arch Bridge

Arch bridge, with extremely high aesthetic value, acting as one of the fundamental bridge types, is widely applied in engineering.CFST(Concrete Filled Steel Tube) arch bridge has solved the problem of the application of high-strength material of arch bridge and the problem of the construction of arch bridge,two main puzzles of bridge.Therefore,it has gained a booming opportunity in our country. With the increase of the span of the arch bridge,the stability problem becomes more and more evidence and it is one of the most important control factors of arch bridge design.Stability problem is divided into two sorts.The first one can come down to evaluate eigenvalue problem finally, which is easy to be calcaulated. Duing to the effect of the geometry nonlinear, the material nonlinear and original bug, the ultimate load calcauleated by the second one is more reasonable comparing to the true result.This paper studys on influencing factors of stability of arch bridge by MIDAS/Civil 2006,search the contribution which has been given by Rise-span ratio, the form and stiffness of transverse bracing, the stiffness of Arch Rib and Hanger Rod, and give some advices on designing arch bridge.Analyse the stability of the CFST arch bridge by eigenvalue buckling analysis method and nonlinear stability buckling analysis method with Ansys.Seen from the result of the calculation, it indicates that due to the influence of material nonlinear the safe stability coefficient draws from nonlinear stability analysis method is far lower than the one does from eigenvalue buckling analysis method. The safe stability coefficient only decreased a little when taking into account geometrical nonlinearity. But when the geometrical nonlinearity and material nonlinearity are all considered, the ultimate load is more lower than the former. So we make a conclution that we must consider the geometrical nonlinearity and material nonlinearity when study the stability of the CFST arch bridge.