Assessing catenary arches for bridge design in South Africa : a preliminary study

Abstract

Bridges form a vital component of South Africa’s transport infrastructure, yet many are susceptible to failure due to environmental stressors and suboptimal design. Recent disasters, including the 2024 KwaZulu-Natal floods, have underscored the fragility of current bridge systems and the need for resilient structural solutions. While circular arches are prevalent due to their historical effectiveness, this preliminary study investigates the viability of catenary arches as an alternative. Through comparative finite element analysis, the structural performance of catenary and circular arches was evaluated, focusing on moment and stress distribution, deformation, and material efficiency. Results reveal that catenary arches offer more balanced internal force distribution, reduced material consumption, and enhanced resistance to lateral forces. These characteristics suggest that catenary forms may serve as a more resilient and cost-effective bridge solution in regions prone to extreme conditions. This study lays the groundwork for further optimisation and supports the integration of catenary geometries into future South African bridge designs.