Partial Continuity in Prestressed Concrete Girder Bridges with Jointless Decks
Jointless multi-simple span deck-girder (composite concrete deck with steel or prestressed concrete girders) bridge construction has been accepted as an alternative to jointed construction. Bridge deck joints add to the construction and maintenance costs of the bridge. Bridge support bearing pads deterioration is a common problem in bridges with jointed bridge decks. One of the methods used for building a jointless bridge is to provide a link slab that connects the decks of the adjacent spans. This study mainly focuses on the behavior of the link slab and its effect on the behavior of the bridge system as a whole. The scope of the study is to develop FE models to analyze the variation of forces, stresses and moments in the link slab as well as the level of continuity generated in the girder system. The analysis is carried out for different bridge parameters which are likely to affect the behavior of link slab; namely, bearing stiffness, skew angle, span lengths and debonding length ratio of link slab.
The present study helps in understanding the effects of the aforementioned factors on the behavior of the link slab and the system. The study also proposes development of a modified three moment equation for different parameters. The parameters which influence the three moment expression are the bearing stiffnesses, material properties and geometric information. A thorough parametric study is required to validate the expression. The results can be used for development of a design procedure for the link slab and the expression can be used for analysis of the link slab.
The results obtained show that the link slab behaves more like a tensile member rather than a bending member with the increase in bearing stiffness and debonding length ratios. This observation was consistent in all the bridge types and skew angles considered for the study.
Advisor:Steve Cai; Ayman M. Okeil; George Z. Voyiadjis
School:Louisiana State University in Shreveport
School Location:USA - Louisiana
Source Type:Master's Thesis
Keywords:civil environmental engineering
Date of Publication:11/16/2006