MAY GURNEY Geotechnical recently completed the first two phases of piling on a commercial development in Exeter, Devon for principal contractor Rok.
Originally covered by gardens, the site was most recently occupied by a two-storey car park which has been demolished to make way for the four- and five-storey office blocks known as the Senate and Senate Court.
In late January, May Gurney mobilised a CFA piling rig to site to install two 450mm diameter test piles for Senate Court. These were test loaded to a maximum of 2,000kN, twice their required design capacity.
Satisfactory load settlement performances were obtained in each case, giving the goahead for installation of 124 working piles with a reduced factor of safety of 2.0.
All piles were 450mm diameter CFA to depths of 8m-10m, founding in the underlying Breccia and Conglomerate.
To support the buildings and infrastructure around the perimeter of the site, May Gurney designed and built a 60m long contiguous bored pile cantilever retaining wall of 80, 600mm diameter CFA piles at 750mm centres.
Piles were 12m long and fully reinforced.
Rok has now moved on site to build the capping beam to the retaining wall and is carrying out the excavation to the front of the wall.
As GE went to press, May Gurney was due to return to site to install the final preliminary test pile and 138 working piles for the Senate building.