- Steel Bridge Design Handbook Design Example 5: Three-Span Continuous Horizontally Curved Composite Steel Tub-Girder Bridge
- B. Chavel ; J. Rivera
- Book Title / Journal:
- Year: 2012 , Volume: 24 , Series: FHWA-IF-12-052
- Bridge management ; Bridges
- Keywords: Steel Tub Girder Bridge ; Steel Box Girder Bridge ; LRFD ; Bolted Field Splice ; Box Girder Distortional Stresses
- Description
- Tub girders, as closed-section structures, provide a more efficient cross section for resisting torsion than I-girders, which is especially important in horizontally curved highway bridges. The increased torsional resistance of a closed composite steel tub girder also results in an improved lateral distribution of live loads. For curved bridges, warping, or flange lateral bending, stresses are lower in tub girders, when compared to I-girders, since tub girder carry torsion primarily by means of St. Venant torsional shear flow around the perimeter of their closed sections, whereas I-girders have very low St. Venant torsional stiffness and carry torsion primarily by means of warping.
This design example illustrates the design calculations for a curved steel tub girder bridge, considering the Strength, Service, fatigue and Constructibility Limits States in accordance with the AASHTO LRFD Bridge Designs specifications. Calculations are provided for design checks at particular girder locations, a bolted field splice design, an internal pier diaphragm design, and a top flange lateral bracing member design.
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- Steel Bridge Design Handbook Design Example 3: Three-Span Continuous Horizontally Curved Composite Steel I-Girder Bridge
- J. Rivera ; B. Chavel
- Book Title / Journal:
- Year: 2012 , Volume: 23 , Series: No. FHWA-IF-12-052
- Bridge management ; Bridges
- Keywords: Curved I-Girder Bridge ; Bridge design ; LRFD ; Bolted Field Splice ; Cross Frame
- Description
- Horizontally curved steel bridges present many unique challenges. Despite their challenges, curved girder bridges have become widespread and are commonly used at locations that require complex geometries and have limited right-of-way, such as urban interchanges. Some of the important issues that differentiate curved steel girders from their straight counterparts include the effects of torsion, flange lateral bending, their inherent lack of stability, and special constructibility concerns. Also, the complex behavior of horizontally curved bridges necessitates the consideration of system behavior in the analysis.
This design example illustrates the design calculations for a curved steel I-girder bridge, considering the Strength, Service, fatigue and Constructibility Limits States in accordance with the AASHTO LRFD Bridge Designs specifications. Calculations are provided for design checks at particular girder locations, a bolted field splice design, a cross frame member design, shear connector design, and a bearing stiffener design.
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