1.1 This document establishes general principles for the execution of micropiles.They are for:- drilled micropiles a shaft diameter not greater than 300 mm;- driven micropiles a shaft diameter or a maximum shaft cross sectional extension not greater than 150 mm.1.2 Micropiles are structural members to transfer actions to the ground and may contain bearing elementsto transfer directly or indirectly loads and or to limit deformations. Their shaft and base resistance may beimproved (mostly by grouting) and they may be constructed with (see Figure 1):- uniform cross section (straight shaft); or telescopically changing shaft dimensions;- shaft enlargements; and/