Structural Performance and Failure Probability Analysis of Steel Truss Bridges

Abstract

Study presents a comprehensive analysis of the structural performance and failure probability of a steel truss pedestrian bridge. The load transfer mechanism was analyzed under dead and live loads, including bridge self-weight (15 kN/m), deck weight (15 kN/m), crowd load (27 kN/m), and vehicle load (11 kN/m). Stability analysis was conducted using joint and section methods, validated through finite element software. A probabilistic framework employing Monte Carlo simulation (1,000 samples) evaluated failure risks, considering lognormal-distributed nodal forces (mean=5.378 kN, COV=0.3) and rod diameters (mean=0.1 m, COV=0.02). The results obtained from this analysis revealed a system-level failure probability of 15%, which was attributed to series-structure dependency. This analysis also highlighted the sensitivity of the system to material variability and sample size. The implementation of mitigation strategies, encompassing material substitution (Q235 steel) and variance reduction techniques, led to a substantial reduction in failure probability to 2%. This research underscores the necessity of probabilistic methods in enhancing urban bridge safety and reliability, aligning with advancements in structural engineering and risk management.