RIVER SHANNON BRIDGE AND ACCESS ROADS

The scope of the contract was; Construction of approximately 400M of single carriageway, Construction of a five span pre-cast concrete balanced cantilever deck, Construction of single span pedestrian bridge, Installation of drainage, ducting and services, Provision of public lighting, Provision of road marking and traffic signs, Fencing, Landscaping Works.

The bridge is a 150 metre five span pre-cast concrete segmental balanced cantilever deck comprising a single carriageway vehicle deck and separate foot/cycle way deck supported on cantilevers from the vehicle deck. The bridge substructures comprise piled foundations supporting reinforced concrete abutments and intermediate piers. The bridge is connected to the North and South campuses by approximately 400M of single carriageway access road, with separate footpath /cycle track. The road was constructed on an embankment.

Also included in the scheme was a single 15M span reinforced concrete pedestrian bridge linking the access road on the North of the River Shannon Bridge with a student village adjacent to the site.

The viaduct deck was constructed of pre-cast segments and was erected and post tensioned using the balanced cantilever method. A temporary bridge spanning the river was constructed to carry the 120 tonne crawler crane, which was required to lift and place the segments. The segments were erected and temporarily held in position by a temporary stressing system.

Reinforcement was then placed and permanent pre-stressing ducts were fixed to the cast-in anchorage points in the pre-cast shell. A second stage pour was then carried out and as soon as the concrete had reached adequate strength the permanent pre-stressing was carried out. The typical pre-cast shell segments were 9.45M wide and 2.4M long and weighed approximately 50 tonnes.

The bridge won the Irish Concrete Society Award for the Infrastructure Category in 2005.