Case Study -
Space Way, Heathrow
Although GeMech prefer to be involved at an early stage, this project demonstrates how GeMech can work at short notice and offer substantial savings on a secured project.
In early January 2004, GeMech were invited by worldwide consultants, Capita Symonds acting for Brixton Estates, to view trial pits and early soils information on a project at Faggs Lane, Feltham in Middlesex. GeMech provided details of how the investigation should be progressed to offer the best solution in terms of costs versus risk.
Working with Capita Symonds, GeMech identified that ground improvement would be a suitable alternative to the compliant scheme for this industrial development. At this initial stage the site investigation disclosed a potential problem in that the site appeared to be an infilled pit underlain by London clay. Controlled filling had led to water filtering through the granular made ground and softening of the underlying clays. Other tendering contractors, who had equal access to the same information did not seem concerned by this softer material.
By June 2005, Wates Construction Limited had secured the project based upon a vibro stone column solution proposed by another contractor. They now had the benefit of a further site investigation such that the other contractor now wanted to change to a fully piled solution, driving up both contract duration and costs significantly. GeMech were then offered the extra soils investigation and, in discussion with Capita Symonds, developed a semi-raft foundation in areas based upon stone columns with a stand alone column solution on remaining units.
Wates were able to maintain the project at the original tender price without having to resort to piling and a suspended reinforced concrete slab. According to Wates the cost savings generated are an example of what can be achieved, and on this occasion were achieved by GeMech, Capita Symonds and Wates working in close partnership.