Open drill system for creating reinforced concrete piles in ground, uses high frequency vibration to prevent adhesion of wet concrete or earth, when retracting drill pipe

摘要

The hydraulic motor (9) which grips and rotates the drill pipe (11), is mounted on a runner on a vertical support structure (8). When the hole has been bored to a sufficient depth, reinforcing rods are inserted through the drill pipe and concrete is poured in to take up the rest of the volume. Before the concrete has set, the drill rotation is reversed to extract the drill pipe. During extraction, the pipe is vibrated at high frequency by an agitating device (10) below the motor.