We successfully delivered one of Europe’s largest-ever foundation projects at the time, supporting two high-rise towers and transforming 3km of riverside.
To support the delivery of One Nine Elms, a new, mixed residential and commercial scheme, our team delivered what is believed to be the UK’s largest pile removal programme, extracting 127 piles (each 900mm in diameter and up to 33 metres deep) and replacing them with synthetic soil to enable new pile installation.
Our scope of works also included installing 460 linear metres of diaphragm wall, 256 load bearing piles of up to 2.1 metres in diameter and 177 plunge columns. Additionally, we carried out 5 Osterberg pile tests, which test load-bearing capacity, to ensure that the working piles would perform satisfactorily.
The development was constructed on a site with challenging ground conditions, including a substantial deep glacial scour feature infilled with weak soils, requiring the design of the foundations to consider three distinct ground profiles. Despite the challenging ground conditions, we constructed 177 of some of the largest plunge columns ever built in the UK. To manage the size and weight of the development, we created a bespoke plunge column guide frame that rested directly on the piling platform, avoiding casing loads and enabling safe and efficient installation.
Innovation
To save time and accelerate project delivery by six months, we utilised plunge columns and top-down construction. Alongside this we also introduced a new pile integrity testing system, Thermal Integrity Profiling (TIP), that reduced pile integrity verification time – marking the first time the system was used in the UK.
Working closely with our suppliers, Dywidag Systems International, Lindapter and Teekay Couplings, we developed a new Superlatch system to join pile and diaphragm wall reinforcement cages together, improving manual handling and efficiency when installing cages. We also developed a new sonic tube alignment guide to ensure sonic tubes are installed and connected correctly through the dense array of reinforcement bars.
We were able to make cost savings of over £180k by refurbishing an existing set of diaphragm wall stop ends, demonstrating our commitment to sustainable and value-driven engineering.
Diaphragm wall
Discover more about our diaphragm wall construction capability and how we have been successfully delivering large scale diaphragm walls since the 1980s.
