Innovative FlexiArch as Footway Extension to Masonry Arch Bridges

This paper presents a brief history of stone / masonry arch bridges in Ireland and how they have become dangerous pedestrian linkages in close proximity to busy roads. Some of the design modifications to these linkages previously constructed are reviewed, with specific examples of a separate footbridge structure alongside the arch bridge and a footbridge connected directly to the side of the existing bridge.

This paper investigates how a precast concrete arch can provide a widening scheme, producing an extension to the masonry arch aesthetic, but with minimal impact on the existing masonry arch structure or environment. Additional foot / cycleway space is provided beside the carriageway, and importantly, a safe environment to current standards for all bridge users.

The paper concludes by presenting a case study of how the scheme used the FlexiArch solution for widening of Beragh Village Stone Arch Bridge, in Co Tyrone, Northern Ireland. The review includes details of how the precast arch was specially moulded to suit the exact geometry of the arch barrel and its ease of construction which allowed the road to remain open. The value it brought to this scheme in terms of cost, sustainability and aesthetics is discussed.