The project is a seven storey development in west London.
The initial work, done by others, included a site investigation and foundation design based on deep piles.
The building planned to utilise a cross laminated timber frame which reduced the foundation loads to those within the capacity of a raft foundation.
The site history meant that there were considerable obstructions and possible contamination in the ground, which consisted of Made Ground overlying Lynch Hill Gravels.
One of the biggest foundation drivers was the presence of the previous foundations and contamination, which limited the ability to install piles and could potentially affect the stability and settlement of shallow foundations.
WT build a three-dimensional ground model which included the location of the previous foundations and thickness of the Made Ground across the site. An optimised pad, raft and pile design was then undertaken to compare feasible foundation options, which showed that a raft foundation placed on engineered fill would deliver considerable cost, programme and environmental savings.
The geotechnical design parameters were improved by back-analysing load test results to further optimise the raft design.
Photos and render: Whitby Wood