Division of Engineering Research On-Call Services: Task 4: Load Rating of the Combs-Hehl Stringers Under Permit Loads

US Transportation Collection2020PDFTech ReportSwanson, James A.Rassati, Gian AndreaChicchi, Rachel AButler, Martin AUniversity of Cincinnati. Dept. of Civil/Architectural Engineering and Construction ManagementOhio. Dept. of Transportation. Office of Statewide Planning and ResearchUnited States. Department of Transportation. Federal Highway AdministrationOhio. Dept. of Transportation. Office of Statewide Planning and ResearchUnited StatesBridge approachesBridgesDesign capacityFinite element methodLive loadsLoad factorMathematical modelsStringersFHWA/OH-2020-2SJN 135785Final reportThe 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 south bridge carrying eastbound traffic. Previous work not described herein addressed rating of the stringers in the Ohio approach spans of the north and south bridges, identified as spans 7-10, under a suite of legal truck loads and emergency vehicles. The scope of work for the project described herein is the rating of the stringers in the Ohio approach spans under a suite of typical permit loads. The analyses 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.120