Geosynthetic Reinforced Fill Material for Tennessee Bridge Approach Slab Support

The approach slab is constructed at bridge ends to serve as a smooth transition from the highway pavement to the bridge deck. However, motorists usually complain about a sudden change in slope (bump) at the highway/approach slab (H/S) joint that would cause a potential hazard for public safety, damage to vehicles, and rider discomfort. This paper develops finite element (FE) analysis for the differential settlement at the H/S joint when supported by a strip footing that sits on compacted layers of soil embankment with uniaxial geogrid reinforcement. A parametric study was conducted, and the optimum design was found to consist of five geogrid layers equally-spaced within a depth of 2xB below the strip footing, where B is the width of the footing. The inclusion of geogrid reinforcement did not only enhanced the ultimate bearing stress of the strip footing but also redistributed the vertical loads over a wider region of soil embankment and thus reduced settlement. A case study was also presented for modeling the performance of a preliminary design proposed by the Tennessee Department of Transportation (TDOT) for the retrofit of bridge ends. The FE analysis showed a 30%-40% improvement in the ultimate bearing stress of the strip footing when the geogrid reinforcement proposed by TDOT is extended to a depth of 1.5xB below the footing.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; References; Tables;
  • Pagination: 20p

Subject/Index Terms

Filing Info

  • Accession Number: 01763766
  • Record Type: Publication
  • Report/Paper Numbers: TRBAM-21-03980
  • Files: TRIS, TRB, ATRI
  • Created Date: Dec 23 2020 11:10AM