Influence of cross-girder spacing on RC T-beam bridges: a comparative theoretical and finite element approach

Abstract Cross girders are seen as typical elements in different types of bridges. In a T-beam bridge, cross girders are essential in stiffening the longitudinal girders laterally and reducing the exterior girder’s torsion. This study aimed to understand the effects of varying cross-girder spacing in a T-beam bridge by studying the relationship between several cross-girders with key structural parameters like Shear force (SF), maximum displacement, Bending moment (BM) and torsion. For this, different models were prepared in Finite Element Analysis (FEA) software, and cross girders varied from 0 to 10 in number. Here, the span and width of the bridge were taken constant, with several cross girders as the only varying parameter. The loadings were taken as per the IRC code. From analysis, it has been found when considering a combination of dead load and live load, the odd number of cross girders is seen as more effective in live load distribution. Further, it’s seen that BM and deflection decrease when cross girders are increased from 2 to 3 but then increase with further addition of no. of cross girders. Hence, an optimum number of cross girders that reduce BM and deflection is 3. Similarly, a comparison was made between the distribution factor obtained from FEA software and Courbon’s distribution factor, and variations were observed.