STUDIES IN BOX GIRDER BRIDGES USING FINITE STRIP METHOD

Abstract

Box girders have wide acceptance in freeway and bridge systems due to their advantageous structural behavior, pleasant aesthetics and economy in construction. Box girder bridge is a bridge where the main beams comprise girders in the shape of a hollow box. The box girder normally comprises either prestressed concrete, structural steel, or a composite of steel and reinforced concrete. The box is typically rectangular or trapezoidal in cross-section. Box girder bridges are commonly used for highway flyovers and for modern elevated structures of light rail transport. A box girder bridge consists of a top and bottom flange connected by vertical or inclined webs to form a cellular box-like section. Analysis of box girder is complicated because of distortional characteristics of the box section. However ,various method of analysis are available but the method which is to be used for the analysis is finite strip method, because this method gives quite realistic result with less data preparation and less computational efforts. Finite strip method is a hybrid procedure which retains advantages of both orthotropic plate method and finite element concept. This method proves advantageous over vary versatile finite element method for the structures having regular geometry and simple support In present work, an attempt has been made to study the analysis of reinforced concrete box girder bridges using finite strip method. The structural behavior of Box Girder Bridge was studied by varying cross-sectional properties of different component of box girder section. The study consist effect of shape & size of box girder over action and internal forces entities. An attempt has been made to conclude design guideline to decide minimum and maximum thickness and size of individual component like depth of section, top slab, webs & bottom slab for box girder bridges. Also, study concludes guideline to control various design parameters like stresses, moments & limiting deflection for box girder bridges.