STRUCTURAL EFFICIENCY OF BOX-SECTIONS FOR BRIDGES

Abstract

A box girder bridge deck consists of top and bottom slabs connected-by vertical or inclined webs. The area inclosed by the webs and slabs imparts very high stiffness to the box section. The division of the total static moment in the box girder bridge between the total positive moment at midspan is the SAME as that found in beam subjected to same loading. Furthermore, it appears that this is true irrespective of the number of cells in the bridge or transverse position of the, load on the bridge deck. Designing the optimum cross-section of box-girder consists of selecting appropriate value as Box width, web thickness, web slope, soffit thickness, depth of box section. The cross-section of box girder is highly influenced by the Transverse distribution of moment, bridge, span. The present work includes the parametric study of box section to show the variation of transverse moment corresponding to change Ot in indiviSual parameter of box section. The effect of different ratios and their significance is assessed by analysing a number of geometrical properties of single cell, single span, simply supported and straight box girder using the computer program based on Finite strip method. For drawing graphs, "GRAFER" software has been used. iii