Analysis of Haunch Width in Box Culvert for Optimal Design

Abstract

This study investigates the impact of varying haunch width on the design moments of box culverts. Employing a comprehensive approach, 48 models were developed and analyzed using MIDAS civil software. We modeled and analyzed both single celled and double celled box culverts. The analysis and design were based on EN 1992 and PD6694-1:2011. Reinforced concrete design was done according to BS EN 1992-1-1 4.4.1. Graphs of design moments against haunch widths; change in moments against haunch widths and total mass of steel against haunch widths were plotted as shown in the report. The results showed that increasing haunch widths had significant impacts on the top and bottom slab while there were no significant impacts on the side wall moments. The optimal haunch width for a 2mx2m and 3mx3m box culvert was determined to be 300mm and that for a 4mx4m and 5mx5m was determined to be 400mm. These findings offer valuable insights into optimizing haunch width for various box culvert dimensions. Furthermore, significant reductions in moments and steel requirements were observed with optimal haunch width configurations. Notably, a 25% decrease in moments, along with 18% and 27% reductions in total steel usage, were recorded for 4x4 and 5x5 box culverts, highlighting the practical implications of haunch width optimization in box culvert design.