1. Homebush Bay Rail Link l 700 lineal metres of precast concrete arch l 9 different profiles.8 x 2.5 to 19 x 8 l 900 units. l Reinforced soil with precast concrete facing. l 6 bridges.9,000 Square metres. l Aquatic centre basement walls, 3,000 square metres l 3 different panel types/finishes. l Reinforced soil with steel mesh facing. l 2,000 square metres. l Arch foundations plus basement walls.

6. Precast Concrete Arches l 2 piece, 3 pinned precast concrete arch system l Advanced design techniques and a flexible moulding system supplies a customised shape and size to suit your needs

8. Arch Design l Finite Element Analysis l Elasto-plastic soil properties with varying elastic modulus (“Duncan model”); concrete linear elastic l Vertical and horizontal soil pressure and soil structure interaction determined by finite element analysis l Construction sequence modelled in the analysis, including compaction loading l Friction elements to allow slip between soil and arch

9. Arch Construction l Once the first 4 units are installed, 1 crane can be used for installation

10. Constraints on Arch Design l Cover over crown of arch l Volume of excavation l Stability under train impact loading l Complex geometry l Waterproofing of the precast joints

11. Typical Arch Sections

12. Arch Profiles

14. Twin Tunnels and the Station

17. Section Through Twin Arches

20. Arches supported on steel mesh faced reinforced soil walls

23. Conclusion l Fast-track design and construct programme l Driven tunnel reduced disruption l Architectural finishes developed in conjunction with architects and suppliers l Precast arch solution to the cut and cover tunnels provided economic and rapid construction without loss of construction flexibility l Design applied principles of Ecologically Sustainable Development l Reinforced soil and arch structures are inherently energy efficient, using soil-structure interaction to utilise the compressive strength of soil

24. Green concrete at the Homebush Bay Rail Link