SKEW COMPOSITE BRIDGES - ANALYSES FOR ULTIMATE LOAD

The ultimate limit state design for composite skew bridges with slab-o n-I-steel girders requires a reliable prediction of their ultimate loa d capacity. In this paper, the results from a yield-line analysis of p rototype composite bridges subjected to OHBDC truck loading are presen ted and compared with the results from a nonlinear finite element anal ysis of such prototype skew bridges. The favourable comparison between the two sets of results indicates that the collapse loads of skew com posite bridges can be reliably and readily predicted by the yield-line method of analysis. Equations useful for the design and analysis of s kew bridges are given. The experimental results from five composite br idge models tested to failure verify and substantiate the analyses. Re sults of the ultimate loads of six other skew composite bridge models with punched-to-failure deck slabs are also shown. A general and simpl ified method relating OHBDC truck loading to the collapse load predict ed using the yield-line analysis is presented.