- Steel Bridge Design Handbook Design Example 4: Three-Span Continuous Straight Composite Steel Tub Girder Bridge
- B. Chavel ; J. Carnahan
- Book Title / Journal:
- Year: 2012 , Volume: 24 , Series: FHWA-IF-12-052
- Bridge management ; Bridges
- Keywords: Steel Tub Girder ; Steel Box Girder ; Lateral Bracing ; Design Example ; Steel Bridge
- Tub girders are often selected over I-girders because of their pleasing appearance offering a smooth, uninterrupted, cross section. Bracing, web stiffeners, utilities, and other structural and nonstructural components are typically hidden from view within the steel tub girder, resulting in the tub girders clean appearance. Additionally, steel tub girder bridges offer advantages over other superstructure types in terms of span range, stiffness, durability, and future maintenance.
This design example demonstrates the design of a tangent three-span continuous composite tub girder bridge with a span arrangement of 187.5 ft - 275.0 ft - 187.5 ft. This example illustrates the flexural design of a section in positive flexure, the flexural design of a section in negative flexure, the shear design of the web, the evaluation of using a stiffened versus an unstiffened bottom flange in the negative flexure region, as well as discussions related to top flange lateral bracing and bearing design.