Progressive Collapse Analysis of Half-Through Truss Bridges Considering Corrosion Effects

Abstract

This study investigates the collapse mechanism of a half-through truss bridge, focusing on its structural reserves beyond the first failure under different damage conditions. Addressing the challenge of predicting collapse behavior in the presence of localized corrosion, a series of progressive collapse analyses were conducted using a three-dimensional finite element model. The findings reveal that the collapse mechanism is primarily governed by the instability of the upper chord system, even when the stress level is well below yielding. These results were validated using an equivalent two-dimensional upper chord system analytical solution. Furthermore, localized deterioration was shown to significantly reduce the bridge’s load-carrying capacity, potentially causing sudden catastrophic failure. The study provides a unique insight into the collapse mechanisms of corroded steel bridges, filling a critical gap not addressed in previous research. The key contributions include a comprehensive nonlinear analysis of progressive collapse, explicit modeling of localized corrosion effects, and the validation of findings using both 3D and 2D models.