Permanent Sheet Pile Basement, Project Vista
|Client:||Berkeley Homes (Central London) Ltd|
|Summary:||Design, supply, installation of Z shaped sheet piles, in plain uncoated steel, to form a permanent basement.|
Specialist sheet piling contractors, Sheet Piling (UK) Ltd. were employed by Berkeley Homes to install a permanent watertight basement for a single storey underground car park for luxury apartments Queenstown Road, Battersea, London.
Working closely with Berkeley Homes from an early stage to develop an optimum sheet pile design and sheet piling installation solution, Sheet Piling (UK) Ltd proposed permanent solution utilising Z shaped sheet piles.
The design benefit of Z sheet piles was it allowed for a cantilever solution to be adopted in the temporary condition whilst ensuring compliance with the advised deflection limit imposed by the Consulting Engineer. Without this benefit then significant temporary propping would have been required resulting in cost, programme and buildability issues.
The Z shaped sheet piles were installed using silent vibrationless piling methods utilising Sheet Piling (UK) Ltd’s in house fleet of Giken Z Pile Presses.
In order to maintain a constant supply of piles for the two Z Presses, two cranes were hired for the duration of the project, one being a 50t Lattice boom crawler crane from Q Plant and a 100t Telescopic Crawler Crane from Select.
The overall basement perimeter length was approx. 425.0m and all piles were sealing welded to provide a 100% watertight basement in accordance with BS8102:Part2:2009.
The ground conditions on site were variable but predominately consisted of Made Ground, over Soft Clays / Silt Alluvium, over Medium Dense Sandy Gravel, over Stiff London Clays.
For successful pile installation some localised pre-augering and water jetting was required.
The length of steel sheet piles designed varied throughout the project from 10m long to 12m long, and consisted predominately of Emirates Steel EZ18-630 pile section.
Once all piles were installed, a comprehensive regime of pile testing was undertook using an independent specialist testing company to verify the axial capacity of the embedded sheet piles. A total of 14no. dynamic pile tests and CAPWAP Analyses on single un-interlocked test piles at approximately 30 meter intervals around the basements perimeter.