Grillage analysis of I-girder bridge deck superstructure.

In this paper comparison of shear force and bending moment of T beam deck slab having longitudinal girder and cross girder is done using courbon's method (manual analysis) and grillage model (using staad pro). Construction stage wise grillage model is prepared in staad pro. Bridge having carriage widths of 7.5 m have two types of live load as per IRC 6 i.e. Class 70R (W) and Class A-2 lanes. Static check of grillage model is compared with manual calculation having 0% difference. For dead load, shear force and bending moment of girder difference using manual calculation and grillage model comes out to be 0.64% and 2%. In manual calculation the reaction factor of an individual girder is calculated using courbon's method and multiplied with maximum bending moment. In live load calculation, for Class 70R (W), difference in bending moment for girder A, girder B and girder C comes out to be 26.45%, 4.78% and 28.66% but total moment difference is 0.05% while for Class A-2 lanes), difference in bending moment for girder A, girder B and girder C comes out to be 21.57%, 9.92% and 16.53% but total moment difference is 0.7%. So, from the result it can be seen that the total design moment of the girder comes out to be nearer using both the method while the girder wise difference in bending moment is found to be higher for outer girder and lower for inner girder. [ABSTRACT FROM AUTHOR]