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

Abstract

Network arch bridges, first developed by Per Tveit, are recognized for their high structural efficiency due to inclined intersecting hangers that reduce bending moments and enhance stiffness. In order to assess the impact of hanger cross-angles ranging from 25° to 90°, this study offers a three-dimensional nonlinear finite element analysis of a 100 m span steel network arch bridge using MIDAS Civil. Using the El Centro earthquake data, the bridge was examined under IRCbased wind loading and nonlinear time-history seismic excitation. To access differences in axial force, bending moment, shear force, and overall structural behaviour, 19 hanger configurations were analysed. The findings demonstrate that dynamic loading controls bridge response, resulting in tie-beam tensile forces close to 430,000 kN and arch compressive forces up to 350,000 kN. While greatly raising hanger strain, increasing hanger cross-angle lowers axial demand in the tie beam and arch rib. While tie-beam axial forces show a high dependency on hanger arrangement, arch bending moments are comparatively resistant to hanger-angle variation. The most balanced structural performance is achieved by hanger cross-angles between 60° and 75°, which combine lower tie-beam tension, less dynamic compression, and a moderate hanger force requirement. The results provide useful recommendations for hanger layout optimization in steel network arch bridges and create the groundwork for further research on hanger loss, robustness evaluation, and structural health monitoring.