In all piling projects the stability of the plant is key and as such, a suitably designed piling mat is essential if the works are to be executed in a safe and controlled manner. It is particularly important that the working platform does not deteriorate or suffer from any movement and/or heave because in piling work the specialist equipment used has a high centre of gravity and the consequences of a collapse can be fatal.
The traditional method of constructing a piling mat is to import and lay a deep layer of stone. Reductions in stone depth have been mitigated by adding plastic containment grids at the base of the structure to spread loadings and limit shear. This is an unsustainable method of construction adding numerous unnecessary lorry movements of materials to and from the site. Whilst a graded stone mat with a well-designed geogrid giving under support and containment has been proven to meet safety requirements. It is a compromise as the loose stone in the mat can cause deflection and require longer setup. In addition piles have been known to snag going through the plastic geogrid base layer an unnecessary safety issue.
PowerCem with their unique Zeolite based RoadCem technology have for over ten years have been offering onsite stabilisation of in-situ materials to meet all UK piling mat standards. We can achieve loading specifications to meet the requirements of the heaviest of rigs from all soil types even weak organic alluvium soils, which we encountered on the industry prize winning Costain Walton on Thames road bridge project.
“Careful sequencing of the works provided a safe passage for pedestrians, cyclists and vehicles. By using existing and new slip roads, we could erect the bridge without restricting the public right of way. An innovative stabilised earth working platform eliminated 12,000 vehicle movements, 60,000 tonnes of imported virgin material and the need to dispose of landfill bound material.” A244 Walton Bridge – Costain
The in-situ stabilisation process of the bound soil mat can be carried out with either Wirtgen self-drive or Stehr tractor pulled dust free soil mixers.
The high dynamic stiffness of RoadCem bound soil mats has a proven dampening effect which will make driven piling operations, safer and far quicker with easy setup and zero deflection.
The ductile mat with its matrix of interlocking cage like crystals will eliminate breakaway, and cracking around the piles will also be very much reduced, allowing ongoing use of the bound soil mat as a cost-effective blinding and/or foundation element.
We believe that we can save time, cost, and embodied carbon for most piling mat requirements: Driven, Auger and Sheet Pile.
Strength testing can allow early commencement of piling operations and all plant operational certifications can be arranged by our partner team engineers, as part of the installation package.
The wrapping cage like bond created by our patented zeolite technology allows weak, organic, and even sulphate bearing soils to be bound together to form impermeable heave resistant monolith layers that will have a flexural easy to work nature allowing easier pile penetration with very little deformation during the lifetime of the mat.
Case Study of the prize winning Severn Trent Water site at Clay Mills.
A RoadCem mat was chosen to form the base foundation for the £42 million upgrade to the Clay Mills sewer treatment works, which included an Activated Sludge plant.
A Total of 1383 x 9M cast concrete driven piles were required, to achieve this a 6,000 m2 RoadCem stabilised soil piling mat was designed and certified by our partners Rodgers Leask Consulting Engineers of Derby.
The poor ground conditions were comprised of mainly made ground of soft sandy silt to a depth of 2 m, overlaying soft clays. The work was carried out in early January during a period of wet windy weather.
Using the proposed rig loadings for the Roger Bullivant Series 5000 tonne Quiet Hammer rig the required platform thickness under BRE 470 would have been +650 mm. Requiring the removal of 7,000 tonnes of material to landfill and replace with imported stone.
Linear Strain analysis Site testing showed that even with the existing weak in-situ soils a 250mm RoadCem soil mat would give a good margin of safety.
With a dynamic stiffness in excess of ten times that of stone, the Elastic Modulus of RoadCem mats will be far greater than a cement bound equivalent.
The following short video illustrates the dampening effect of our technology and note the lack of loose stone, which can be a safety issue. With RoadCem no surface protection materials are needed.