COMPARATIVE ANALYSIS OF THE BUCKLING FACTOR OF THE STEEL ARCH BRIDGES

The dominant axial compressive force makes the arches become extremely sensitive to the loss of stability. Their stability analysis was first initiated in the late 20th century. The first stability research of single arches was carried out inplane at the elastic stage of the arches. Later the behaviour of arches in the elastic-plastic stage, the initial stresses and geometric imperfections before the arch buckles were also assessed, the effective length of the arches and the out-of-the-plane arch strength conditions were being identified as well as the effect of the temperature on the stability of the arch. The expression of the critical force of the arches connected by vertical hangers with a chord and its dependant elements were defined by Petersen in the late 20th century. The design methodology for the formal design of arches connected by vertical hangers with a stiffening girder is presented in Annex D of the Eurocode 1993-2. Nevertheless, the area of application and the main assumptions are not defined. The first part of the comparative analysis identifies the assumptions for arch bridge modelling under which the buckling factor β dependence curves in Figure D.4 of Annex D to Eurocode 1993-2 can be applied. In the second part a comparison of the the normative βEC factor value and the one established by the numerical experiment with the increase in the number of hangers and change in the hanger network form is presented.