Micro-piles are high capacity, small diameter (5” to 12”) drilled and grouted in place piles designed with steel reinforcement to primarily resist structural headings, micro-piles are rapidly gaining popularity for foundations in urbanized areas or in locations with low headroom and restricted access. They are an ideal choice for underpinning or emergency repairs because they can be installed in virtually any ground condition with minimal vibration and disturbances to existing structures.
Micro-piles may require single or multiple bar requirements. Micro-piling can be done by rotary method. Due to the small diameter of micro-piles, they can only sustain the loads applied to them by the skin friction interaction between their surface area and the surrounding soil layers.
To improve such friction interaction, skin grouting is performed around the pile shaft at the depth of penetration of the pile through the bearing shotcrete.