The ground investigation identified the presence of Made Ground, underlain by the Kellaways Sand and Clay Member, comprising firm, silty clay with interbedded sand layers. A detailed tree survey also confirmed that all plots sit within zones of potential tree influence, making heave protection a critical design consideration.
Concept Design
Design Engineering
SPEEDECK’s geotechnical and structural engineers developed a robust foundation design incorporating 350mm diameter Continuous Flight Auger (CFA) piles, each embedded 0.5m into the underlying rock strata. The rock profile consisted of a thin siltstone layer over weaker mudstone and strong limestone, requiring careful pile design to ensure long-term stability.
Across the development, more than 1,000 piles were installed, equating to over 7,000 linear metres of piling completed within just nine weeks. In total, the foundation design covered 6,370m² of structural slabs, integrating essential heave protection measures to mitigate the effects of shrink-swell soils and maintain the structural integrity of each plot.
Construction
The construction sequence was carefully managed to maintain programme efficiency and site safety. Across all plots works included:
- Installation of the concrete piling mat and working platform
- CFA pile installation and testing
- Completion of blinding and preparation works
- Installation of shuttering and reinforcement
- Concrete pouring and completion
The project was delivered to an agreed 13-week programme, with all works completed safely, efficiently, and to specification.
