Roger Bullivant Limited (RBL) was commissioned to install the COMBISLAB raft foundation and flooring system on a challenging site posing three major ground engineering issues: minimising the impact of contamination, desiccated subsoils with heave potential and very weak working platforms.
COMBISLAB was the only viable alternative to traditional foundations
The site of this large housing development in Ashford, Kent was originally part of an industrial estate made up of various buildings and infrastructure associated with rail workings and repair workshops. This in itself posed difficulties dealing with contamination but was further compounded by underlying clay sub soils which in some areas were desiccated requiring heave protection measures.
The low-lying site was also poorly drained and prone to flood during periods of heavy rainfall making it extremely difficult and potentially hazardous to work. Limiting traffic movements to and from site was also key due to the site’s close proximity to a main railway line and other industrial operations.
Main contractor Kier chose the RBL COMBISLAB foundation system, which is one of the company’s most versatile foundation products. The design centres on the use of patented details to create the combined foundation and flooring system and relies heavily on the engineering expertise and innovation which have been associated with RBL for many years. For this project the use of Sectional Flight Auger (SFA) piles was specified to minimise the working platform requirements by using smaller medium-sized piling rigs.