Division of Engineering Research On-Call Services, Task 2: Rating of the Stringer System of the Approach Spans of the Combs-Hehl Bridge

The Combs-Hehl Bridge is a series of structures over the Ohio River near Cincinnati spanning between Ohio on the east end and Kentucky on the west end. The overall bridge consists of four approach spans on the Kentucky side of the river (spans 1-4), two main truss spans over the river, (spans 5 and 6), and four approach spans on the Ohio side of the river (spans 7-10). The bridge carries interstate route 275 and, as a result, consists of two independent structures: the north bridge carrying westbound traffic and the south bridge carrying eastbound traffic. The scope of work for the project described herein was limited to rating of the stringers in the Ohio approach spans of the north and south bridges, identified as spans 7-10. The Ohio approach spans of the south bridge consist of five stringers spaced at 8’-2½” spanning 25’-0” between floor beams that are supported by two girders. These girders are spaced at 32’-10” and are supported by piers spaced at 200’, for an overall length of 800’. Because of an on-ramp for the westbound traffic on the Ohio side of the river, the north bridge is similar, but not identical, to the south bridge. The Ohio approach spans of the north bridge consist of seven stringers spanning 25’-0” between floor beams that are supported by two girders. The north bridge girders are also supported by piers spaced at 200’, for an overall length of 800’. Since the north bridge was designed to accommodate an on ramp, the width of the bridge changes over its length, with stringer spacing varying from 5’-5½” to 8’-3” and the girder spacing varying from 32’-9” to 49’-6”. The analysis and rating of the approach spans were conducted using three methods. The first method was based on one-dimensional beam-line (1DBL) models to determine demands and traditional hand calculations to determine capacity. The second approach was based on three-dimensional linear and elastic (3DLE) finite element analyses of the bridges to determine demands and traditional hand calculations to determine capacity. The third approach was based on three-dimensional nonlinear and inelastic (3DNI) finite element analyses of the bridges wherein the finite element model itself was able to determine both the demand on, and the capacity of, the stringers. Each of the methods is described in this report.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Figures; References; Tables;
  • Pagination: 21p

Subject/Index Terms

Filing Info

  • Accession Number: 01717667
  • Record Type: Publication
  • Report/Paper Numbers: FHWA/OH-2019-15
  • Contract Numbers: SJN 135785
  • Files: TRIS, ATRI, USDOT, STATEDOT
  • Created Date: Sep 4 2019 7:55AM