2019 CSCE Annual Conference - Laval (Greater Montreal)

2019 CSCE Annual Conference - Laval (Greater Montreal) Conference


Title
DEAD LOAD DISTRIBUTION IN SKEW CONCRETE SLAB-ON-PRECAST CONCRETE I-GIRDER BRIDGES


Author(s)
Mrs. Atefeh Iranmanesh, Ryerson University (Presenter)
Dr. Khaled Sennah, Ryerson University
Abstract

In order to improve the bridge construction, using prefabricated elements has recently been more common in North America. Fabricating different bridge elements off-site has many benefits including higher material quality and durability, more efficiency in time and cost, increased safety of the work zone, less environmental impacts and decreased traffic disruptions. Moreover, many old bridges need rehabilitation, repair or replacement. Utilization of precast systems can significantly minimize the economic effects of a full-lane closure in large urban regions. The inconvenience caused to the traveling public can save time and tax payer’s money as well as enhancing the work zone safety. Currently, the Canadian Highway Bridge Design Code (CHBDC) specifies empirical equations for the moment and shear distribution factors in skew slab-on-girder bridges. However, there is no information available in the literature to verify the use of such equations for the design of the fully-precast CPCI girder bridges. Furthermore, the equations are limited to bridges with skew parameters less than a certain value specified in the code. However, skew bridges are necessary in some conditions such as crossing an obstacle or highway interchanges. The design of majority of skew bridges were not precise since they were designed as right bridges due to lack of researches. Since CHBDC load distribution factors were determined for general slab-on-girder bridges with limited value of skew parameters, a parametric study is required to investigate the applicability of these factors for precast bridge systems and bridges with higher values of skew parameters and without transverse intermediate diaphragms. In this study, a finite element modelling (FEM) was used to obtain load distribution factors for such bridges under self-weight and superimposed dead load and then correlate them with those available in CHBDC. Conclusions and recommendations for future research will be presented.