Design and Analysis of Steel Truss Pedestrian Bridge for Rural Community Crossings in Niger State

Inadequate river crossing infrastructure in rural Niger State restricts access to schools, markets, and health facilities for thousands of residents in the North Central geopolitical zone. This study presents the structural design and analysis of a modular steel truss pedestrian bridge suitable for spanning small watercourses in rural communities, with a design case based on a river crossing in Suleja Local Government Area. The design process follows the provisions of BS 5400-2 for pedestrian bridge loading, incorporating live load of 5 kN/m2 and wind loading derived from the local climatic zone classification. A Warren truss configuration with verticals was selected for its material efficiency and ease of fabrication by local steel fabricators. Member sizing was determined through classical method of sections analysis and verified using a finite element model. The design incorporates a reinforced concrete abutment system founded on bored piles to accommodate the soft alluvial soils prevalent along the river bank. Results of the structural analysis confirm that all member forces remain within the permissible limits of Grade S275 structural steel under ultimate limit state loading combinations. Deflection under full pedestrian loading was calculated at span/380, comfortably within the serviceability limit of span/200. The estimated cost of material and fabrication is approximately 12.4 million Naira, representing a cost-effective solution for rural infrastructure gap-filling. The study advocates for the adoption of standardised modular bridge designs in state rural development programmes. Keywords: steel truss, pedestrian bridge, rural infrastructure, Niger State, structural design.