Parametric Study for Structural Performance of Steel Network Arch Bridge Using Finite Element Method

Abstract

Background: Network arch bridges provide efficient load transfer through inclined and interesting hangers; however, the influence of hanger cross-angle on structural response under combined wind and seismic loading remains insufficiently quantified.

Methods: This study investigates the effect of hanger cross-angle on the structural performance of steel network arch bridge. A three-dimensional nonlinear finite element model of a 100 m span and 13 m wide steel network arch bridge was developed using MIDAS Civil. Nineteen hanger configurations with cross-angle ranging from 25° to 90° were analyzed under IRC – based wind loading and nonlinear time-history seismic excitation using the El Centro earthquake record. Axial force, shear force, and bending moment responses of the hangers, arch ribs, and tie beams were evaluated.

Results: Increasing the hanger hanger cross-angle reduced axial forces in the tie beam and arch rib but substantially increased hanger tensile forces. Arch bending moments showed comparatively limited sensitivity to hanger-angle variation, whereas tie-beam axial forces were strongly affected. Seismic loading produced substantially greater structural demands than wind loading. Hanger cross-angles between 60° to 75° provided the most balanced structural performance by reducing tie-beam tension and arch compression while avoiding excessive hanger forces.

Conclusion: The study provides a systematic nonlinear FEM-based comparison of 19 hanger configurations under consistent wind and seismic loading conditions and proposes a practical 60°-75° design range for the investigated 100 m steel network arch bridge.