Deflection Reliability Analysis for Composite Steel Bridges

Reliability methods offer a very efficient serviceability assessment of structures with randomness due to geometry, material, and loading. Al-Awsej composite bridge in Diyala-Iraq span 33.2m has been studied its deflection reliability index for three lifespans was estimated compared the target index. The indices have evaluated through First-Order Method (FORM) Monte Carlo Simulation (MCS) method. MCS adopted Matlab functions generate pseudo-random numbers considered parameters, but it requires large sample sizes estimate small probabilities failure. That leads use reduction variance such as Importance Sampling (IS) Four cases random loading were included: dead load live loads, i.e. uniformly distributed knife-edge load, military sidewalk load. Some assumptions are needed assess system behavior, where is represented parallel uncorrelated perfect correlated girders. two investigated 1, 10, 50 years. For case, shows range 5 4. In contrast, case offers between 4 2. With these assumptions, results show that no failure occurs, hence still within target.