Pre-augering is a technique that Sterk uses to reduce soil resistance and to make sheet piles easier to press or vibrate. Reducing vibration nuisance in the case of vibrating sheet piling is another reason to opt for pre-augering.
Sterk has various leader-guided cranes that can be equipped with drilling motors up to 30 metres. We also have free-hanging drills with which we pre-auger up to 16 metres. We can attach these to our hydraulic cranes. So there is no need for a separate rig.
If desired, bentonite cement can be injected during pre-augering to reduce any settlement.
Pre-augering is a technique we apply a lot. Particularly in inner city areas, we often apply this technique in combination with the vibration-free pressing of sheet piles to reduce soil resistance. For example, we used this technique in the realisation of the construction pits for the parking garages of The Mall of the Netherlands and the Jaarbeursplein in Utrecht.