TWM prepared a value engineering redesign of a complex 2-span curved steel girder bridge over I-55 in south St. Louis. Roadway and structure geometry resulted in complex detailing of cross frames, bearing seats, and girder dimensions. TWM was responsible for the type, size, and location planning of the bridge and MSE walls. The redesigned project was a single bridge (the original was dual structures) that was narrower, had one less girder line, eliminated a longitudinal open joint and raised median, and was approximately 58’ shorter than the original design.
- Length and Width: 275′ x 68′-5″ curved continuous welded steel plate girder bridge
- Span Arrangement: 124’/151′ along CL
- Superstructure Type: 84″ web composite steel plate girders; Maximum girder cambers ranged from 15″ to 23″
- Substructure Type: Integral abutments supported on H-piles and a multiple circular column pier on a footing supported on H-piles; substructures are skewed from 45 to 57 degrees from radial; the embankment at either abutment is retained by MSE walls
- Seismic Category: SPC B
- Horizontal Alignment: Curved with a radius of 819′ at CL
- Special Features: An existing triple box culvert behind one of the abutments was strengthened with the addition of a slab bridge to allow for the additional fill required for the MSE wall; the roadway geometry resulted in complex detailing of cross frames, bearing seats, and girder dimensions