Title: Pinned-end moments in simple span multi-girder bridges
Abstract: This paper demonstrates the potential for significant live load-induced moments at the pinned end of a simply supported, single span, straight composite girder bridge without skewed supports. When a simple span bridge model is subjected to asymmetric vertical loading, it produces differential girder end rotation. If the pinned boundary condition is eccentric to the girder, this rotation causes varying longitudinal displacements of the deck. This longitudinal movement produces in-plane shear in the composite deck, which must be balanced by a longitudinal force to maintain equilibrium. The eccentric longitudinal reaction results in an end moment at the pinned boundary, a pinned-end moment (PEM). Currently, the literature does not adequately address this phenomenon. To address this knowledge gap, a parametric study was conducted on 588 standard steel girder bridge designs to understand the relative magnitude of PEMs and the sensitivity of PEMs to critical bridge parameters. Live loads were found to induce end moments of up to 50% of the midspan moments and the pinned-end reactions (PERs) as high as eight times the design braking force. Moreover, the PEMs were found to be most sensitive to the deck aspect ratio (width/length), transverse expansion bearing restraint, and the longitudinal bearing and substructure stiffness at the pinned end. These research findings indicate that structures with the largest PEM values are those with a high deck width to length ratio, transverse restraint from guided bearings, and relatively high substructure stiffness.
Publication Year: 2021
Publication Date: 2021-04-25
Language: en
Type: article
Indexed In: ['crossref']
Access and Citation
AI Researcher Chatbot
Get quick answers to your questions about the article from our AI researcher chatbot