Analysis of Box Culvert With and Without Haunches

Abstract

Recent developments in computer technology have made it possible the use of Finite Element methods for 3D modeling and analysis of reinforced concrete structures. Several works have already been done on Finite Element analysis of Box Culverts. In the past study of box culverts, effect of haunch has not been considered in reduction of flexural stresses. In this study Finite Element analysis of Box Culverts is carried out with ANSYS software which is a computer based analysis tool on Finite Element Method. In this study a Box Culvert of clear inside dimensions 6m×6m and thickness of slabs and side walls as 0.5m has been used. Modeling is done with plain cement concrete by giving two basic properties viz. modulus of elasticity and poisons ratio. Modeling with these properties gives exact stresses which are likely to develop after loading. First a Box Culvert is modeled without providing haunch or chamfer and later it is analyzed by providing haunch of varying size viz. 0.5, 1.0, 1.5, 2.0 times thickness of wall. After analysis of these models in ANSYS, results of stresses, deflection has been taken from post processing mode to carry out comparative study between five cases. Also graphs have been plotted to see variation of flexural stresses in different models to get Bending Moments. Finally with the help of these Bending Moments exact thickness and reinforcement required is carried in all the models and finally comparative quantity and cost study between these has been presented. At the end, a comparative study of conventional method and finite element method is carried out in two computer aided programs namely STAADPro and ANSYS 14.5 which shows huge difference in deflection, shear stress and equivalent stress in the same structure.