E-Found®, HGV Test Centre, Bodelwyddan
HGV Test Centre, Bodelwyddan, Denbighshire, N. Wales
Client: Eatonfield Holdings Ltd.
Principal Contractor: Pochin Contractors Ltd.
Engineers: Smith Associates
Geotechnical issues encountered on the site would have traditionally required the use of piling for the foundations for the test centre; this however, was not cost effective for this project. CON-FORM was therefore approached by the engineers to develop a lower cost alternative.
The site had previously been a wooded area which had caused the underlying clays to become desiccated due to the tree roots absorbing most of the moisture in the ground.
Post construction, this had the potential to create major technical issues to non-piled foundations. If the clays became re-hydrated, the clay would swell and heave upwards, causing the building to move.
CON-FORM, using its specialist ground engineering capabilities, proposed its unique E-Found® foundation solution to overcome these concerns. This required the excavation of the desiccated clays under the building and its immediate perimeter area, down to a 3 metre depth. The excavated clay was then modified with lime and re-hydrated to its optimum moisture content.
It was then replaced in controlled layers and tested, prior to subsequent layers being placed. CON-FORM applied its rolling dynamic compaction every 1 to 1 1/2 meters of lift to minimise/eliminate any future differential settlement. This induced further consolidation on the backfilled materials, even though testing on the placed materials had already passed the standard earthworks specification.
The additional differential settlement induced on the 3 metre fill beneath the foundation area averaged 120mm. Traditional pad foundations could now be founded within CON-FORM’s re-engineered works.
An additional benefit to Pochins, the main contractor on this project, was that all trenches and pits dug in the re-engineered ground did not require shuttering. This had a further benefit as the absence of shuttering on the pad foundations, service and drainage areas, meant less backfill and less excavated volumes requiring disposal.
Key Benefits of the CON-FORM Solution
- CON-FORM's specialist capability and track record enabled it to utilise its unique E-Found® foundation solution, eliminating the need for piled foundations and enabling the project to meet key affordability criteria.
- Further significant savings realised on follow on construction works.
- Environmentally friendly solution with geotechnically challenged local materials modified to make them fit for purpose.
- Quick, effective and simple solution.