ABSTRACT
ABSTRACT. The longitudinal stress increase due to the local stiffening effect of webs in box-girder concrete bridges was found to be, possibly, more than 50% over those obtained from simple elementary beam theory analysis. A comprehensive study has therefore been performed using linear-elastic finite element method which is able to reflect accurately the influence of the flanges, webs and diaphragms especially in the vicinity of the supports, as opposed to many of other traditional methods such as folded plate method, finite strip method and so on. The study reported in this paper also reveals the shear lag effect due to different geometric properties and loading cases. The results obtained find the present British design code too conservative. Recommendations of design parameters are also included in the paper.
