Medium-Span Timber Footbridges – A Comparative Analysis with Traditional Steel and Concrete Structures (Technical, Environmental, and Structural Aspects)

This master's thesis focuses on the design and structural verification of a timber pedestrian bridge within the Seine-Escaut Est project in Wallonia, specifically Sector 5 of the Nimy-Blaton-Péronnes Canal. It forms part of a broader comparative study of alternative structural solutions using different materials, proposing a sustainable and contemporary design based on timber. The thesis is structured in two parts: the first introduces the infrastructural and territorial context; the second, more technical, details the design, structural checks, and comfort assessment. After a historical and typological overview of timber bridges, various conceptual solutions are compared, leading to the selection of a glulam arch bridge for its structural efficiency, aesthetics, and environmental value. Finite element modelling is used to assess internal forces, displacements, and dynamic response under pedestrian loads. Structural checks comply with Eurocode 5, focusing on both Ultimate and Serviceability Limit States, including lateral-torsional instability and thermal effects. Pedestrian comfort is evaluated via modal analysis and time-domain approaches, with potential mitigation strategies like Tuned Mass Dampers. The study concludes with a technical-economic comparison between timber, steel, and concrete, and an environmental sustainability assessment through CO₂ footprint and energy classification. Results confirm the structural validity and sustainable potential of timber in modern pedestrian infrastructure.