Royal Wells

Pile Type: CFA

Number of Piles: 214no.         

Diameter: 500mm  

Depth: 11.5m

The development is located within Turnbridge Wells at the former Kent & Sussex Hospital site. The geology of Turnbridge Wells is known to be very challenging for piling through, and for this part of the development there was a variable thickness of Sandstone to penetrate before terminating the 500mm dia. piles in to the Turnbridge Wells Sand at depth. 

The strength of the overlying Sandstone varied between 0.45-6.0 MPa which could make construction of CFA piles (as proposed) very difficult without carefuk consideration for most suitable piling rig and augers. 

Due to the nature of the site geology, it was decided that we would make use of our Bauer BG-20 rig. With 200kN crowd force and 200kNm torque, this machine was able to construct all 213no. 500mm diameter piles and 1no. crane base piles successfully and ahead of schedule , allowing the client to commence substructure works sooner. 

The sandstone layer encountered above the design depth of the piles meant that the boring head of the augers were under substantial stress and wear. With this in mind, the BG20 and augers selected proved to be ideal for this development.