Cased Secant Piling (CSP) piles are constructed by drilling hollow stem augers encased within a string of casing to the required depth. A twin rotary drive system rotating in opposite directions allows soil extraction and casing installation simultaneously. The soil from the pile are removed from the top of the auger and brought down to ground level via a chute acting as a safe system of work.
With CSP piling there is always a risk of some soil escaping the chute due to the volume of material being removed. As such JRL Group planned to use site exclusion zones to protect operatives working near the piling rig and mobile over sail gantries to protect the public from this risk on Rivington Street and Old Street.
JRL Group contacted the piling rig manufacturer Casagrande to see if an additional safe system of work could be developed to remove the risk of soil falling from the drive system. Through close communication and coordination a system was developed that captures the soil via a grillage attached around the drive system.
This safe system of work was trialled at Art’otel in a location where there were no risk to pedestrians from falling soil and was very successful. This grillage along with a strict monitoring and cleaning protocol meant the risk of falling soil could be eliminated, removing the need for the mobile gantry.
This has now been adopted onto the remaining JRL Group Casagrande CSP piling rigs. This means all future works are able to be completed in a safer more efficient manner than before
Casagrande has now updated their CSP piling rigs designs and are coming with this modification as standard to ensure that the risk of falling soil has been eliminated.