Foundations for the New Tower of London

Spire London has the biggest foundations of any building in Brittain

What are the foundations like for what will be the tallest residential tower in Western Europe?  Richard Piggin with Bachy Soletanche explained what will be supporting the £800million Spire London tower in a article.

The tower, located in the Canary Wharf area (formerly West India Docks) will be 67 stories, 771 feet tall containing 861 apartments.  It has a footprint of 32,292 sq. ft. at the base.  The foundation system will consist of 66 drilled shafts (or bored piles), each 6.8 feet in diameter and ranging in depth from 131 feet to 220 feet.  These foundations are bigger than anything used on the Shard (Brittain’s tallest building).

The article is a little confusing on the capacity of each pile, they mention 108 mega “neutrons” (I’m assuming that was supposed to be Newtons), which is over 24,000 kips.  I’m not sure if that is an ultimate or allowable capacity.

The interesting part is that this site is located directly over Crossrail’s Elizabeth line.  The piles had to be constructed in two “corridors” straddling the line with an 11 ft exclusion zone on either side of it.  I’m guessing that span is the reason for a massive 13 ft thick concrete pile cap.

The article also mentions in passing some of the shoring elements necessitated by several historic buildings around the perimeter and the North Dock.  The shoring consists of 310 (secant? tangent?) concrete piles, 51 feet deep to provide a waterproof barrier.

Source: Building the new Tower of London Image: Metro.News

Disclosure: Bachy Soletanche is the parent company of sponsor, Nicholson Construction