Micropiles are deep foundation used when very limited space or headroom is available for execution with conventional pile rigs. Besides, micro pile bearing is a small working load and can perform on hard or shallow rock formation, where precast pile is unsuitable. Micro pile machine also can be modified for underpinning works where limited head room encounters.
In a typical installation process, a high-strength steel casing is drilled down to the design depth. A reinforcing bar is inserted and high-strength cement grout pumped into the casing. The casing may extend along the full length of the pile, or it may only extend along part of the length of the pile, with the reinforcing bar extending along the full length.
Typically, the size of micro pile ranging from 200mm diameter to 450mm diameter with capabilities to drill until 40m. Method of drilling including using drag bit, down the hole hammer or ODEX system either by wash boring or air flush depending on sub soil condition.