Pile forming method by drilling, enlarging, pressure-grouting and filling

The method of depositing the pile includes drilling hole, laying reinforcement bar cage, depositing concrete and pressure ejecting the motar. The operation procedure is to expand the hole when it is drilled to make one or more spaced cavities from the top to the bottom of the hole. The cavities enlarge the bearing areas of the pile in the bottom and periphery, so that the pile have higher bearing capacity compared with the pile deposited in normally drilled hole.