Summary
Roughan & O'Donovan completed permanent and temporary works design of this major, multi-span viaduct at the N7/N18 interchange northwest of Limerick City.
Awards
- ACEI President’s Award for Design Innovation 2011
- Irish Concrete Society Infrastructural Category Award 2011
Solution
Structure B11 on the Limerick Southern Ring Road Phase II (Limerick PPP Scheme) carries N7 mainline traffic over a slip road and tidal creek.
It comprises:
- Fully integral, twin viaducts, 169.6m and 178.5m in length
- 6 spans on the south structure and five spans on the north structure
- In situ cast reinforced concrete boxes with a maximum span/depth ratio of 23
- Inset, single leaf piers to minimise visual impact
- Shallow deck cantilevers to enhance the bridge’s slender appearance
Challenge
The challenge lay in designing a high quality structure that could:
- be constructed economically in complex soft ground conditions
- settle well within a rural environment
- service a very busy traffic flow
Highlight
Our innovative design provided substantial benefits, in terms of construction and whole life maintenance costs, to our client.
Services provided:
- Bridge engineering design
- Geotechnical design
- Temporary works design
- Alignment and road works engineering design