Design of Concrete Box Culvert Based on the Hydromorphometric Properties of Natural Drainage Basins: A Case Study of the Mesos-Suluq Road Culvert

Abstract

This study presents an integrated hydraulic and structural design approach for a concrete box culvert, addressing the intersection of the Messous-Suluq road with WadiBab basin. A comprehensive hydrological investigation of WadiBab basin, established by SCS-Type II method. Key parameters such as peak flow, time of concentration, and flood duration were estimated, deriving essential hydraulic requirements. A statistical rainfall analysis of historical data (1981-2022) was performed, defining design storm events and calculating a maximum discharge of 5.6 m³/sec for a 1000-year return period. The basin's concentration time was determined to be 25.4 hr, with runoff velocities 0.981 m/sec due to steep upstream slopes. Subsequently, a three-cell square box culvert was designed with dimensions of 3.5m in width and height, ensuring hydraulic efficiency. The structural design stand by AASHTO 3.4.1-2 LRFD specifications. All applicable loads, including self-weight, soil overload, live loads, were quantified. Structural analysis, performed with ROBOT2023 software, determined a maximum moment of 102.37 kN.m and a maximum shear force of 176.7 kN. Reinforcement detailing was executed, ensuring adequate resistance to these forces. The findings highlight that a morphohydrological analysis of WadiBab basin, employing ArcGIS 10.8 for geospatial data processing, provided the foundational data for this design. It was concluded that an optimally designed square box culvert can achieve equivalent structural and hydraulic stability. Recommendations include the integration of remote sensing and GIS for basin studies, the construction of dams for rainwater harvesting, regular culvert maintenance, and strategic placement of culverts within main valley courses to enhance flood management.