Engineers are warning of up to three months of traffic disruption after unveiling plans to demolish and replace a defective road bridge on the boundary between Cork city and county.
A special agreement has been reached between the city and county councils to allow the city council undertake the essential works on the Curraheen Road bridge, on the western outskirts of the city.
The Section 85 agreement will allow the city council to carry out the demolition of the bridge which spans the Twopot River and carry out extensive reinstatement works on a site which straddles the city and county councils’ administrative areas.
The bridge leads from Bishopstown to the University Technology Centre, home to thousands of workers at firms including Abtran and RedFM, to the Curraheen Park Greyhound Stadium, to Cork City FC’s training grounds, and to an off-ramp to the Ballincollig bypass.
Visitors to Marymount Hospice also use the bridge regularly. It is used by thousands of vehicles every day.
But surveys have confirmed that the single span masonry arch bridge is defective.
Following a recent inspection, engineers found dropped stones in the crown of its arch.
Repair works were undertaken immediately but they did not fully address the noted defects, or adequately supplement the strength of the structure, the city’s director of services in the roads and transportation directorate, Gerry O’Beirne said.
In a report to councillors, he said that the application of a gunite layer — a sprayed concrete repair method applied to the underside of bridge arches which is often used in these kinds of situations — could not be done because of the history of flooding at this site and because it would reduce the bridge’s hydraulic capacity — reduce its flow capacity.
“On further investigation, it is now recommended that the existing structure be demolished and replaced with a precast concrete culvert,” his report recommended.
Councillors sanctioned the Section 85 agreement which now clears the way for a list of proposed works, including the demolition of the existing masonry arch bridge, and subject to agreement, the temporary removal of the boundary wall to University Technology Centre to facilitate the temporary diversion of a northern footpath for pedestrians and cyclists during the works.
A new precast concrete culvert will be installed, as well as rock armour and geotextile in the riverbed at both ends of the reinforced and waterproofed structure.
The roads and footpaths will be realigned and reinstated, with lined with road and cycle-lane markings.
Final design works are being completed and it is hoped that the work could start within weeks. It is expected that the entire project could take up to 12 weeks to complete. Traffic diversions and alternative routes will be publicised.
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