This tool was designed to provide a reforming capacity in three separate ways: as a plug for pile pressurisation; for direct reforming via packer inflation; and for direct reforming via jacking.
In the first instance, the tool is installed in the top of the pile and the packer is inflated to secure it in place. Water is then pumped through the packer to pressurise the pile below the packer plug, thereby reforming the pile hydraulically. The packer inflation pressure must be sufficient to anchor the tool against the force generated by the reforming pressure.
For direct reforming using the packer alone, the tool is inserted into the pile area requiring reforming and simply inflated. As inflation proceeds, the packer pushes the pile and surrounding soil into a circular shape. This method generates enormous reforming loads behind the packer, e.g. at seven MPa total load is approximately 25,000 tonnes but is very localised and requires that the packer can first be inserted into the area that needs reforming.
Where the tool cannot enter the area to be reformed, it is installed immediately above this zone. The packer is inflated to anchor the tool in position and then the jack is stroked out to reform the pile ahead of the packer. Subsequent deflation and retraction allows the packer to be lowered in behind the jack nose and the process may then be repeated as necessary to progressively reform the tip of the pile.
Finally, it must be acknowledged that development of these tools was a team effort from the concept stages through prototype testing, manufacture, final testing and delivery.
The project used the combined talents and resources of the many individuals and corporations. For the most part the work was conducted in an atmosphere appropriate to this team approach and the project benefited and was successful as a result.