ABSTRACT
The High Speed Two (HS2) is the new high-speed railway for Britain. Thame Valley Viaduct is part of HS2 Phase One from London to West Midlands. In order to cross the Thame River and adjacent flood plain area, The Thame Valley Viaduct made up of 36 spans an overall length of 880m it is proposed. The foundation for the viaduct involves large diameter bored piles. The temporary works to construct the causeway over very soft soils consist of 18no. piling platforms with approximate 15,000m2 and an adjacent haul road connecting the platforms with an overall length of 1,000 m. The ground conditions generally consists of very soft to soft alluvium with undrained shear strengths of 0kPa-36kPa. It is proposed to support the perimeter of the piling platforms with a 45°/70° reinforced soil wall using layers of geogrids wrapped. A design is also required for the 18no. piling platforms.
