Stability Analysis of Tied-Arch Bridges Under IRC Loading Condition Using Finite Element Method

Abstract

Tied-arch bridges are structured so as to guide outward horizontal forces of the arches to the chord tying both arch rib ends and further to the support through deck-connected tie-rods. Finite element is most often used method to analyze real bridges; we have various number of FE software available; Midas is one of its kind used to accurately simulate the real bridge. A very less effort has been done till now to analyze the tied-arch bridges for IRC loading conditions; this paper investigates the stability of 200 m span bridge under IRC loading cases. Efforts are made to find out the influence of straight, inclined, and network hanger arrangements on the structural behavior of bridge and also to justify the results; thickness of deck slab is varied for the above hanger arrangements. Objective of the work was to determine the most optimal arrangement of hangers along the deck slab for a road bridge, consisting of two steel arches using finite element analysis method. Nonlinear static analytical method was used for the analysis by using an FEM software Midas Civil. Validation of software for AASTO LRFD vehicle was done. 3D models of single span 200 m slab tied-arch bridges for different hanger arrangements have been done to determine maximum displacement, bending moment, and reactions. Deck slab was also varied for the different types of hanger arrangements that determine minimum displacement, minimum bending moment, and maximum support reaction to find the best combination of deck slab thickness and hanger arrangement.