Greek Street - Deck Construction Works

Description

Greek Street Bridge is a two span post tensioned structure in which the latest PTSI assessment concluded that the structure is understrength and overstressed. Engineering standard NR/CIV/025 has been used to manage the substandard structure in the short term with additional monitoring in place. Specific elements of concern included exposed concrete reinforcement which has begun to corrode on the deck soffit, seepage of water onto the soffit which will cause degradation to accelerate further. The most recent assessment report stated that the risk of failure was 'High' to 'Very High' and that deck replacement is required in 2025, otherwise the structure would need to be closed to road traffic until completely reconstructed, due to the overstress and deterioration it would not be safe to operate. The project proposal is to replace the existing bridge with a single span removing the central pier in a 21 day core possession in August 2025. This will require alterations to the existing OLE equipment that runs underneath the structure. The highway will also be closed for a significant period whilst construction works are undertaken to replace the bridge - circa 50 weeks. The deck construction works will commence once all beams are landed, connected and waterproofing membrane is installed. The sub-contractor will then be responsible for setting up all formwork and erecting steel re-enforcement (Opportunity to construct in cages may arise during design development, but please assume in-situ at this stage). Sub-contractor to then provide 2no. concrete pumps for duration of their pouring works. Sub-contractor to also finish concrete. The scope of work included in this Subcontract includes but is not limited to provision of all resources required to undertake the following items of work in accordance with the requirements of the Subcontract other that the items which the Schedule of Attendances specifically identify as being provided by the Main Contractor.