Cavan County Council
Roughan & O Donovan
N87, Swanlinbar, Co. Cavan
Strengthening, widening and upgrade of 3 nr bridges along the N87 in the vicinity of Swanlinbar, Co. Cavan. One bridge was an concrete structure and the other two were masonry arch structures. Works involved conservation reconstruction & repair of the existing masonry bridges and construction of a cantilevered concrete deck to widen the concrete bridge in the town of Swanlinbar.
The works to the masonry arch bridges involved repointing, stitching & scour protection works to the masonry arches, removal of the existing masonry parapet, the construction of insitu abutments & bridge deck to widen the bridge and reconstruction of the masonry parapet. The widened bridge structure allowed for the construction of footpath along the road. the works also involved construction of the footpath, timber post & rail fencing, safety barriers, masonry parapets, traffic management, environmental mitigation measures, macadam surfacing, line marking and landscaping.
The majority of the works were carried out on the concrete bridge structure over the river Claddagh in Swanlinbar. These works involved extensive traffic & pedestrian management, reducing the carriageway to a single lane & installation of a temporary footbridge over the river with associated footpaths. The works involved significant environmental controls due to the instream works and the importance of the river as part of the Erne SAC. Environmental controls included cordoning off & treating Japanese’s knot weed, silt curtains, settlement ponds and filter bags to pumps when dewatering.
The works to the bridge involved construction of an insitu cantilevered deck to the bridge to allow the incorporation of wider footpaths on the bridge. A temporary scaffold was erected as a working platform & edge protection for the works, the existing parapet, footpath & road were removed, the deck was scabbled back to expose the steel reinforcememt in the existing deck and the new steel reinforcement was fixed to it for the cantilever deck, formwork erected and the new deck was poured. The concrete was waterproofed prior to installation of ducting, drainage & mains water services across the bridge and the reconstruction of the road, footpath & masonry parapet. The footpath & parapet were removed on the opposite side of the bridge to widen the footpath and public lighting installed to the bridge.