CFA - CONTINUOUS FLIGHT AUGER PILING Rock and Alluvium offer an innovative CFA Piling solution utilising state of the art CFA fleet – fully instrumented with computerised pile monitoring systems and capable of operating in close proximity to other buildings and structures. CFA piles should be formed using fully computerised rigs. The flight auger is drilled into the ground to the required design depth. The auger is withdrawn whilst concrete is pumped through the hollow stem. This aspect is monitored by the instrumentation system. Upon completion of the concreting phase, reinforcement is inserted into the pile shaft. The CFA piling system is very versatile, being suitable in both stable & unstable ground conditions. It is capable of dealing with the presence of ground-water. With this type of pile there is no open bore at any time. The upward movement of soil at all times and the advance of the rising concrete prevent the development of preferential flow paths or downward transportation of contaminants. The CFA process is both quiet and relatively vibrationless making it ideal for environmentally sensitive situations and where piling is to take place close to neighbouring properties and services. The pile testing regime adopted for any site will vary depending on the following factors;

� Quality of the site investigation � Design factor of safety � Number of piles � Consistency of the geology � Any specific contractual requirements Maintained load & sonic integrity testing may be used to demonstrate pile performance and integrity respectively. Our state-of-the-art CFA fleet is fully instrumented with computerised pile monitoring systems. Graphical outputs direct to a touch-screen computer in the cab of the rig enable the piling process to be monitored by our trained operators. The accuracy and traceability provided by the system enables quality assurance to be given. Rock & Alluvium have one of the UK’s largest fleets of Soilmec CFA piling rigs with depth capacities of up to 31 metres and typical diameters in the range of 300 - 1200mm. Safety First � Piling platform must be designed & constructed for the safe operation & manoeuvering of the piling rig. � High pressure concrete pipelines to be regularly inspected for wear. � Banksman must control the rig movements. � Mechanical auger cleaner to be used, in order to prevent hazard from falling materials. � A manual handling assessment to be made prior to lifting operations. � Projecting pile reinforcement to be fitted with protective ‘mushroom’ caps.

GROUND ENGINEERING TECHNIQUE