Abstract
Composite box-girder bridges are recently used in modern highway urban system because of their profitable and structural aptitude advantages. North Americans Codes of Practice specify empirical equations for girder moment and shear forces in such bridges in the form of live load distribution factors. These factors were proven to be conservative in some cases and underestimate the response in other cases. Therefore, an extensive parametric study, using the finite-element modeling, was conducted to examine the key parameters that influence the load distribution factors of such bridges. A total of 276 prototype bridges were analyzed to evaluate girder bending moment, shear force and deflection distribution factors for simply-supported composite multiple box-girder bridges when subjected to CHBDC truck loading. Design parameters considered in this study were bridges span length, numbers of design lanes, number of box girders and girder spacing. Based on the data generated from parametric study, sets of simple empirical expressions were developed for bending moment; shear force and deflection distribution factors for such bridges. A correlation between the finite-element results with CHBDC and AASHTO-LRFD empirical expressions showed the former are more reliable in structural design of composite box-girder bridges.
Highlights
The results showed that the most effective parameters influencing the load distribution factors were the span length, number of design lanes, and number of box girders and the span-to-radius of curvature ratio
Two live load conditions were considered in this study, namely: (i) CHBDC truck loading including the dynamic load allowance, and (ii) the lane loading, including a combination of 9 kN/m uniform load to be distributed over a 3 m width and 80% of the truck loading without dynamic load allowance
Bases on the data generated from the parametric study, the following conclusions are drawing: 1. The most important parameters that affecting the structural behaviour of simplysupported bridge are bridge span length, number of design lanes, number of box girders, flexural-to-torsional stiffness of girders and truck loading condition
Summary
The objectives of the research are to: 1. Investigate the parameters that influence the behavior of straight -supported composite multiple box-girder bridges subjected to CHBDC truck loading and correlate the results with available CHBDC and AASHTO-LRFD specified values to examine their accuracy in structural design. 2
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.