Collapse Loads of Continuous Skew Composite Bridges

The prediction of the ultimate load capacity of composite skew bridges with slab‐on steel I‐girders is required for the ultimate limit state design of such bridges. In this paper, the prediction of the most probable yield‐line patterns of failure under different cases of loadings is presented. The prediction is based on a parametric study (companion paper) as well as on laboratory test results on simply supported and continuous two‐span skew composite bridge models. Good agreement is shown between the theoretical and experimental results. The results show that the skew‐angle‐bridge‐aspect ratio, as well as the type of connection between different elements of the composite bridge are the main factors in predicting the collapse load and the failure pattern of the bridge. The degree of composite action between the diaphragms and deck slab is also shown to have an influence on the ultimate collapse load of the bridge. A method relating American Association of State Highway and Transportation Officials (AASHTO) truck loading to the collapse load is presented. The derived equations can be readily used for either designing skew composite bridges or analyzing existing ones. A worked design example is presented.