Progressive Collapse Analysis of Curved Cable Stayed Bridge

This study examines the progressive collapse behavior of curved cable-stayed bridges, evaluating deck curvature (75-175m), pylon types (H-shape, single), and cable systems (fan, harp) using 24 MIDAS Civil finite-element models.Analyses under IRC Class 70R loads reveal deck curvature intensifies torsional demands, with H-pylons experiencing 30-35% higher torsion in harp systems versus fan systems.Single pylons exhibited minimal cable-geometry sensitivity but increased longitudinal moments (Y-direction) under tighter curvatures.H-pylons demonstrated reduced longitudinal moments but higher Zdisplacements in fan systems, while harp systems showed controlled displacements.Time period analysis indicated fan systems' lower stiffness, with periods 10-15% longer than harp systems.Cable failure simulations highlighted inner cables near pylons redistributing 25-40% less force than outer cables, improving collapse resistance.Curved decks induced force imbalances, with curvature-side cables sustaining up to 18% higher pretension.The study advocates harp configurations with H-pylons for curved spans due to balanced load distribution and redundancy, while emphasizing the necessity for curvature-specific IRC guidelines.These findings offer critical insights for optimizing resilience against progressive collapse in geometrically complex cable-stayed bridges, informing design strategies to enhance structural robustness.