1. A case study of embankment construction on soft alluvial soils in Limerick, Ireland Trevor Orr, Trinity College, Dublin, Ireland Marina Pantazidou, National Technical University of Athens, Greece

2. Where are we? North west Europe…

3. Where are we? – Zoom 1 Ireland…

4. Where are we? – Zoom 2 West Ireland… River Shannon

5. Where are we? – Zoom 3 West of Limerick River Shannon

6. The approach to Limerick Tunnel River Shannon Highway embankments on soft alluvial soils Submerged tunnel Cross section to be studied

7. View south towards the tunnel Buggy & Curran (2011)

8. Continuing south: Killarney & Lakes (Ladies view)

9. Heading north: Cliffs of Moher

10. Bypassing Limerick through the tunnel Buggy & Curran (2011): Figure 1 Cross section to be studied

11. Different earthwork types along highway Buggy & Curran (2011): Figure 10 ground improvement: vertical drains & surcharge chainage 0+000 Cross section to be studied at chainage 4+150

12. Geologic profile in the vicinity of cross section at chainage 4+150 3m glacial till limestone 4+150 2.9m alluvial clay/silt topsoil CPT 517 CPT 516

13. Cross section 4+150 8.75m embankment: required height for motorway 2.75m surcharge 3m soft silt/clay glacial till & limestone 11m class 2C fill 0.5m drainage layer class 6C fill 25.6m 2 1 1 1 Drains at a 1.3m center-to-center distance

14. Simplified cross section 4+150 8.75m embankment 3m soft silt/clay glacial till 26m 2 1 GWL

15. Undrained shear strength for 4+100 – 4+180 segment c u =0.3xp o ’ design profile CPT 517 CPT 516