Pile-driver assembly and method of using it

A pile-driver assembly for driving a pile into the ground, the assembly including:

• a casing defining a chamber, the chamber being configured to house a fluid;
• a positioning element configured to position the casing at or on the pile, wherein at least a portion of the positioning element is positioned between the chamber and the pile;
• an actuating means comprising at least one actuator, the actuating means comprising a fluid chamber configured to house a fluid,
• wherein the actuating means is configured to be actuated to displace the chamber relative to the positioning element such that the chamber moves away from the pile to an elevated position, and
• wherein the actuating means is configured to be actuated to release the chamber from the elevated position for displacement towards the pile such that a force is exerted by the chamber on the positioning element, to controllably drive the pile into the ground;
• and
• a buffering means comprising at least one buffering element, the at least one buffering element comprising a buffering chamber housing a buffering fluid, the buffering means being configured to controllably buffer the force exerted by the chamber on the pile through compression of the buffering fluid as the pile is driven into the ground;
• wherein, the buffering means is configured to rebound the chamber to a rebound position when the pressure of the buffering fluid produces an upward force exceeding the weight of the casing,
• wherein the actuating means is configured to be further actuated to displace the chamber relative to the positioning element, such that the chamber moves from the rebound position to the elevated position, and
• wherein the actuating means includes a locking means configured to maintain the chamber at the rebound position, wherein the locking means comprises a return valve having an open configuration and a locking configuration, wherein, in the locking configuration, the return valve is configured to allow the amount of the fluid within the fluid chamber of the actuating means to increase but not decrease.