BOX-GIRDER BRIDGE ANALYSIS BY FINITE STRIP METHOD FOR I.R.C. LOADINGS

Abstract

A box girder bridge consists of top and bottom slabs connected by vertical or 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 depend 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 cross-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 advantages over the conventional finite element method for the structures having regular geometry and simple support conditions. The present work includes the analysis of box girder bridges subjected to dead load and I.R.C. live loads. The loadings of IRC class 7OR (tracked and wheeled), class AA (tracked and wheeled) and class A. has been incorporated in the program. The analysis program calculates bending stress, shear stress, bending moment and torsional moment at the desired sections along the span. However, the program is limited to simple support conditons without intermediate diaphragms.