Effect of Inclination of Web in the Behaviour of Through Type U-Girder Railway Bridges

Abstract

Precast concrete through type U-girders is now being widely adopted in metro railway bridges. It is an alternate to box girders when the structure is constructed in earthquake sensitive areas. The main advantage of through type girders is that, it requires less overall height. Since the horizontal force is acting at lower level, the moment induced due to lateral forces will be lower in magnitudes. The use of U-girders also leads to material savings about 20–30% compared to box girders. The analysis of through type rectangular shaped bridge structure was already carried out by a few researchers and the available literature on comparative studies in the analysis of through type trapezoidal shaped U-girder railway bridges is limited. The present study addresses this lacuna. The linear elastic analysis and material nonlinear analysis of trapezoidal shaped, U-girders have been conducted using finite element software ANSYS. A comparative study has been done between linear and nonlinear analysis and also the effect of inclination of the web in the behaviour of U-girders has been studied by adopting different cross sections of girders with different angle of inclinations and with the same cross-sectional area. The study proves that the inclination has an effect on the flexural stiffness of U-girder.