Evaluation of Safety Margin on Steel Truss Bridge After-Fracture State

Abstract

This paper presents fracture critical member identification of steel truss bridge by determining demand to capacity ratio of axial load and linear redundancy analysis of truss bridge. Bridge redundancy evaluation has become crucial in both designing new
highway bridges and repairing or retrofitting old bridges after bridge collapses around the world in recent years. This study aimed to evaluate system redundancy of truss bridge after failure of one critical main truss member. Redundancy analysis is investigated through a case study of four spans continuous steel truss bridge. Finite element (FE) analysis was carried out using SAP 2000 software. In this paper, six cases of diagonal member removal are considered for redundancy analysis. Results from FE analysis showed that the effect of member removal is highest when the damaged truss diagonal member is near the support.