Resistance factors for steel highway bridges

Resistance (performance) factors for bridge members composed of rolled and welded steel sections are developed consistent with the live and dead load factors given in the Ontario Highway Bridge Design Code (OHBDC).Ratios of the load components of seven different spans of plate and box girder bridges are used with the statistical data for loads used in the development of the OHBDC. Monte Carlo simulation techniques are used to compose distribution curves for the various resistance functions from distribution curves describing the appropriate geometric properties, material properties, and test/predicted ratios. Using the 0.001 and 0.05 fractiles of the distribution curves so obtained for the resistances, mean values and coefficients of variation are obtained for equivalent lognormal distribution curves.Resistance factors are then developed for the fully plastic moment resistance, the yield moment, the inelastic buckling moment resistance, the elastic buckling moment resistance, the moment resistance of comp...