Hollow Bar Micro Piles are constructed using bespoke hollow, threaded steel bar which is drilled and simultaneously grouted. It is typically drilled using rotary percussive techniques and bore stability is maintained by pumping grout through the centre of the steel bar as the pile is progressed.
The steel bar is progressed into the ground using sacrificial drill bits selected to suit the ground conditions present. The steel bar forms the structural element of the pile and the grout acts as the load transfer mechanism from the steel bar to the ground to achieve the geotechnical capacity.
This technique is suitable for a variety of ground conditions and is not susceptible to issues relating to groundwater levels. This technique is particularly effective in granular soils where the geotechnical capacity regularly exceeds those calculated through conventional methods.