Barnhalt Bridge, Carrickfergus
Carrickfergus, Northern Ireland
| Client |
DRD Roads Service |
| Consulting Engineer |
DRD Roads Service |
| Value |
£600 k |
| Contract Period |
- |
Construction of a replacement road bridge, over the Belfast to Larne railway line with associated approach embankments, drainage, safety fencing and road works. The project included the design of a reinforced earth substructure for the bridge deck and the approach embankments.
The Barnhalt Bridge Replacement Contract was a £0.6m contract for Roads Service to renew an 18m span structure which carries Taylors Avenue in Carrickfergus over the Larne Line Railway. (This section of railway was re-laid under a separate contract by FP McCann in Joint Venture with Amec.)
The new alignment of the Barnhalt bridge permits passing two way traffic and enabled the removal of a weight restriction on this route. A Tensar reinforced earth system was used to construct the 8.5m high approach ramps and abutments. A combination of precast concrete block facing and vegetated steel mesh panel was used for the elevation finish. Each abutment is founded on 65 mini piles and a 600mm thick reinforced concrete pile cap.
FP McCann designed the elements of the project included the piles, pile caps, and reinforced earth. The superstructure comprised 18 pre-stressed concrete TY beams on integrated in-situ reinforced concrete bank seats. A 500T mobile crane was used to lift the precast beams into place. The 16 intermediate beams weighed 16T each and the 2 end beams which incorporated integrated edge parapet upstands weighed 45T. The lifts were carried out during night time railway possessions. The integrated bridge deck was poured with concrete from our Mallusk batching plant which delivered 145 cubic metres of concrete to the Carrickfergus site in less than four hours.