ANALYSIS FOR THERMAL STRESSES IN CONCRETE CURVED BOX-GIRDER BRIDGES BY FINITE STRIP METHOD

Abstract

Box-girder sections are most suitable for highway bridges curved-in-plan, because of its certain structural advantages;-particularly when the span is large and/or radius of curvature is small. Single cell box girder with overhanging top flange and vertical or inclined webs is the most popular cross-section for concrete bridges, and are widely used in medium span range. Numerous attempts have been made to analyse curved box-girder bridges for static and dynamic service loads, but very few attempts have so far been made to analyse curved box-girder bridges for secondary loads, like that due to non-linear differential temperature distribution through the bridge cross-section. Temperature distribution through the cross-section of box-girder bridges are generally non-linear and two-dimensional. Nature of the horizontal temperature distribution through box-girder bridge cross-sections due to diurnal and seasonal temperature variations are not yet well established. In absence of any IRC code recommendation regarding design temperature distribution through concrete bridge sections; - differential vertical temperature distributions suggested by BS:5400 part-2:1979 are adopted for the analysis of thermal stresses in reinforced concrete simply supported single cell cylindrically curved box-girder bridges.