Category:

Elactagh Bridge, Co. Donegal

The existing Elactagh bridge is a twin span composite structure in Donegal which carries the R252 over the Elactagh River. The road is a strategic route through the county linking the towns of Ballybofey & Stranorlar in the east of the county to Glenties and Dunglow in the west of the county. The river is a tributary of the River Finn, and as such forms part of the River Finn Special Area of Conservation (SAC). The existing bridge is constructed from masonry abutments, steel and concrete beams and a concrete filler deck. The existing bridge had deterioriated to such an extent that a new bridge crossing was required.   AtkinsRéalis were commissioned by Donegal County Council in April 2013 to provide the engineering consultancy services for the realignment of 365m of the existing R252 and the design of a new single span integral structure over the River Elactagh.   The detailed design phase of the scheme commenced in May 2013 and was tendered in August 2013.  The overall scope of works included the following elements:

– Traffic management to maintain traffic over the existing online Bailey Bridge on the R252;
– Construction of a new single span integral bridge south of the existing bridge with reinforced concrete abutments and wingwalls, precast concrete prestressed beams and precast concrete parapet walls; The location of this bridge is within a Special Area of Conservation (SAC) of the River Finn.
– Realignment of approximately 367m of roadway with 260m following the existing R252 Regional Road and 100m on green field
– Tie in to existing side roads and accesses to dwellings;
– Removal of existing Bailey Bridge
– Demolition and removal of existing bridge deck and parapets
– Excavation of existing earthworks
– Provision of temporary works to enable the existing R252 to remain open whilst the approach roads and proposed bridge are being constructed;
– Provision of cofferdam to enable the abutment and wingwall foundations and stems to be constructed within the river channel;
– Installation of a Road Safety Barrier System;
– Installation of a road drainage system;
– Installation of new watermains and connections to existing watermains and Road Signage and Road markings.

The scheme involved close liaison with the Loughs Agency to agree the proposed construction methodology of the bridge abutments in order to reduce the time spent working within the river channel.  During the construction phase AtkinsRéalis provided on site full time supervision.   The construction phase of the project produced a number of challenges most notably at one abutment location where the rock level reduced significantly over a short distance resulting in a dig out and replace of the existing poor ground.  Another challenge was achieving final agreement between Donegal County Council and the adjacent landowners on accommodation works.

Client: Donegal Co. Co.

Status: Complete