We are working on a complex 4 phase scope on a new development forGilbert Ash in Farringdon, London. The overall scope of the project includes demolition of an existing multi storey car park, and construction of a new commercial development and hotel.
A major challenge to the project is that it is situated over the top of the live Network Rail Clerkenwell Tunnel with the top of the masonry tunnel is approximately 11m below road level.
The 1st phase of our works was to static test existing 750mm and 900mm dia. piles, installing new reaction piles, and incrementally loading to 690t and closely monitoring displacements. We also extended the existing piles by 4m above the previous cut off levels to facilitate testing. Thanks to our geotechnical designer CGL (Card Geotechnics Limited) and Non Destructive Testing Services Ltd for their efforts in this regard.
The 2nd phase of our works was to design and install new load bearing piles up to 31.5m in length and 900mm in diameter in typical London ground conditions to supplement the utilisation of the existing piles.
In the next phases of works we will be installing 160m of sheet pile retaining walls, along with propping to accommodate the new basement and all other ground works on top of the Clerkenwell Tunnel footprint.