Parametric Study on Straight PSC Box-Girder Bridges

A parametric study has been carried out for single, double, triple, and four-cell straight PSC box-girder bridges using the software CSiBridge 22 which is based on finite element method according to provisions of Indian Road Congress. The critical load analysis shows that the maximum deflection and stress are obtained under 70-R tracked vehicle load. The variation of stress and deflection is studied under 70-R tracked vehicle load and prestressed load. It is found that the cross sections considered for this study, i.e., single-, double-, triple- and four-celled straight PSC box-girder bridge having constant volume satisfy the stress and deflection criteria as per Indian Codal provisions for different span lengths 50, 60, 70, 80, 90 and 100 m for a depth of 2.4 m. When the span length is varied from 50 to 100 m, the vertical deflection due to prestress load increases by about 47%, 48%, 69% and 76% for single, double, triple and four cell, respectively. Lowest vertical deflection is obtained in four cell box-girder bridge as the span length increases hence for higher span length, it proves to be a very efficient section. The results obtained in the study may be useful in the analysis straight PSC box-girder.