Unsupported browser

For a better experience, please update your browser to its latest version.

Your browser appears to have cookies disabled. For the best experience of this website, please enable cookies in your browser

We'll assume we have your consent to use cookies, for example so you won't need to log in each time you visit our site.
Learn more

Technical paper: The Pinnacle – design and construction of large diameter deep base grouted piles in London

Dinesh Patel, Sarah Glover, Jonathan Chew and Jenny Austin, Arup. This paper was first published in GE’s November 2015 edition.


This paper describes the design and construction of deep base grouted bored piles for The Pinnacle (figure 1a) – a planned 290m high skyscraper in the City of London. Pile loads from this structure were expected to be up to 45MN, and this meant that the piles had to extend into the Thanet Sand stratum, 63m below ground level. The decision to have single piles per column also meant that, not only were the piles the deepest, but also the largest ever built in the City, at 2.4m in diameter.

This paper also presents the results of an instrumented base grouted pile load test to approximately 25MN. This paper was initially presented at the EFFC’s 2010 conference in London but work on The Pinnacle halted after the foundations and the substructure up to ground level were completed sometime after presentation of this paper.

The paper has been updated for GE as work on the site has recently restarted and some of the existing foundations will be used to support the new 22 Bishopsgate development (figure 1b), which is being undertaken by developers Axa Real Estate and Lipton Rogers. In addition to the restart of work on site, there has also been a rise in the use of base grouted piles in London in the last 12 months and the assessments made in this paper in regard to design and construction are relevant to future projects. 


Have your say

You must sign in to make a comment

Please remember that the submission of any material is governed by our Terms and Conditions and by submitting material you confirm your agreement to these Terms and Conditions. Links may be included in your comments but HTML is not permitted.