ANALYTICAL INVESTIGATION OF SLAB BRIDGES WITH INTEGRAL WALL ABUTMENTS

The design of a single-span bridge with integral wall abutments is simple when the bridge has no skew. For skewed bridges, the design is complicated by higher shears and moments that develop near the obtuse angle. The finite element method can be used to compute these moments and shears; however, it is time consuming for everyday design unless specialized pre- and postprocessors are available. A linear elastic finite element analysis was used to investigate the effects of dead loads, AASHTO live loads, and earth pressures on 20 different bridges with spans ranging from 15 to 60 ft and skew angles varying from 0 to 60 degrees. The results of the study have been used to produce charts that are adequate for design purposes. These charts relate the moments, shears, and deflections in a skew bridge to those in a 1-ft-wide plane frame taken along the longitudinal center line of the skew bridge. Work to refine and verify the results obtained to date through laboratory model testing and nonlinear finite element analysis is ongoing.