Terradrive Piling & Foundations Ltd. completed piling operations for the new US Custom Border Patrol (CBP) at Shannon Airport, for PJ Hegarty & Sons Ltd.
The piled foundations comprised a mixture of conventional driven precast concrete piling, low headroom bottom driven mini-piling and restricted access Jacked-In mini-piling.
The project imposed very onerous limits on vibration due to the sensitivities of the baggage screening equipment. The client installed four vibration monitors underneath the screening equipment, and action limits were set to alert the contractor to levels approaching prescribed limits.
For this work, Terradrive used 300mm square precast concrete piles driven with a 40kN hammer to carry loads up to 1,050kN. Vibration monitors showed the green light all along the pile driving, even at the shortest distance of 1 metre; proof indeed that vibrations associated with installing driven piles are grossly overstated.
A further demand of the project involved having to install piles inside the baggage handling hall behind the lugagge conveyors – while the conveyors and screening equipment were operational! This work required a prefabricated displacement pile as the risk of disruption to equipment and operations from spoil arisings and placing of wet concrete was too great. In this area, Terradrive employed a 180mm diameter steel tubular pile to carry a safe working load of 325kN per pile. The piles were “pushed” into the ground using hydraulic jacks that were bolted to the existing RC slab.
As one part of the project involved works on the airside, only a few metres away from the aircrafts, precast piling proved to be the most efficient solution, particularly because of the strict health & safety and security requirements in place. In fact, the process for installation and supply of precast driven piles offered reduced risks to FOD (Foreign Object Debris), which can potentially be very damaging to aircrafts.
Upon completion of this project, Shannon Airport is to become the first European airport benefiting from pre-clearance agreement with the US.