Crossrail is building a new railway for London, running from Reading and Heathrow in the west, through 42km of new tunnels under London to Shenfield and Abbey Wood in the east. The project is building 10 new stations and upgrading 30 more while integrating new and existing infrastructure.

St Giles is located meters away from the Tottenham Court Road tube station. H Smith was awarded the demolition contract to prepare the site for new construction. The site consisted of an island of buildings of various ages. The building was a few single stories to a five storey building that formed the front of St Giles High Street.

The works consisted of careful demolition to remove redundant listed buildings, installation of weatherproof protection to exposed walls, underpinning, retaining walls and the installation of a piling mat for the next phase of the project.

The Challenge

The next phase of the project after H Smith had completed their work was to construct piled foundations and retaining walls. A 100 tonne piling rig was to be used. There was a risk that the rig could topple if it slid off a backfilled platform.

The Solution

The solution was to build a solid piling mat that would take the loads.

A wall was designed 1.8m wide x 3m high. The wall was to be built using interlocking concrete blocks a solution BlockWalls could provide.

BlockWalls produced working drawing for the site to determine the number of blocks required.

The site was very tight and traffic congestion in London is high.

Blockwalls worked closely with the site manager to ensure loads where derived on time.

The blocks are supplied with a lifting bolt and clutch for simple movement of the blocks on site.

The blocks were placed on a concrete foundation. The area behind the blocks was then backfilled and consolidated in layers.

Finally, a concrete raft was cast over the block to complete the piling mat.

On completion of the piling, the piling mat would be removed from the site.