Micro piles can be supplied in sizes for 30mm diameter up to 130mm diameter. These are hollow bar piles with a hole through the centre varying in size from 11mm diameter up to 60mm diameter, which allows injection grouting to take place if required.
The micro piles can achieve very high pile capacities and are quick to install and usually do not require casing off through the fill material. They can often have advantages over other piles and can be installed utilising small drilling plant.
The micro piles consist of a continuously threaded bar as mentioned in various diameters and lengths to suit the drilling rig to be used. A sacrificial bit of varying sizes is used to give the required diameter hole for the bar and grout and is very unusual if the holes size is above 300mm in diameter.
Advantages over conventional piles:
- Work in compression as well as tension
- Does not require temporary casing
- Improved mechanical ground/grout interaction reduces overall depth
- Dramatically increased production rates.
- Lightweight rotary percussive drilling equipment
- Easily installed in confined space and limited access.
- Perfect for structural repairs and underpinning