Variation of Shear Coefficient and Reaction Coefficient with Span in Skew Bridges

Abstract

Skew bridges are generally provided at oblique intersectionin flyovers and bridges. They are also encountered at
oblique intersection of road and rail crossing.The increasing pressure of traffic has led researchers to conduct a lot of
research in skew bridges. Studies carried out in skew bridges has shown that skew bridges as compared to right bridges over
estimates the live load moment, while live load shear and live load reaction are under estimated. To recognize the effect of
span on live loadshear force and live load reaction in skew bridges, a study has been carried out and presented in this
paper.The study is carried out on a two lane reinforced concrete T-Beam bridge with 3 longitudinal girders, resting on three
supports. IRC loadings as per IRC 6:2000 have been used. Spans as provided inpractical situations in India are chosen. The
span has been varied from 12 m to 21 m at 3m intervalwhile skew angle is varied from 00
to 400
at 100
interval. These span
and skew ranges are mostly encountered in most skew bridges.The results are presented in form of shear coefficient and
reaction coefficients. It is observed that with increasing span the shear force shared by outer girder increases. The maximum
increase is 13.5% for class 70 R wheeled loading for 400
skew. The reactions also show similar behavior.