Deformation Analysis of Missouri Bridge Approach Embankments

Missouri has recently experienced below expectation performance or the bump-at-the-end of the bridge phenomena at bridge approach slab transitions. Information on approach slab performance was collected state wide to assess if the problem was limited to regional or geological distribution. Finite element analysis was then used to explore the soil embankment-bridge structure differential settlement in two Missouri bridges; MoDOT Bridge A6031 in Livingston County, and MoDOT Bridge A5834 in Pulaski County. These two cases are indicative of the types of soil conditions encountered in the Northern Glaciated Plains region (deeper compressible foundation soils) and the Southern Ozarks region (shallow rocky clays) of Missouri. The construction sequence was tied to the analysis by applying the embankment and slab loading following the construction records. The finite element method results compared well with observed displacements. Recommendations for construction sequence are provided