ANALYSIS OF BOX GIRDER BRIDGE USING FINITE STRIP METHOD

Abstract

A box girder bridge consists of top and bottom slabs connected by vertical and inclined webs. The area enclosed by the webs and slabs imparts very high torsional stiffness to the box section. An analytical solution of box girder bridge under load is rather complicated due to the development of distortional stresses which depends on many factors like cross sectional dimensions, depth to span ratio, number of cells and their shapes. Various methods of analysis aim at finding the correct distribution of stresses across the section. Finite strip method is a hybrid procedure which combines some of the advantages of series solution of orthotropic plates with the finite element concept. This method has considerable advantage over the conventional finite element method for the structure having regular geometry and simple support conditions. The present work includes the analysis of box girder bridges subjected to dead load and IRC live load. The loading of IRC class 70R (tracked and wheeled), class AA (tracked and wheeled) and the class A has been incorporated in program. The analysis program calculates bending stresses, shear stresses, bending moments and torsional moments at the desired sections along the span. However, the program is limited to simply support conditions without intermediate diaphragms.