The present disclosure relates to a soil displacement drill comprising a drill pipe; a widening at one end of the drill pipe that is provided with (1) a screw blade for screwing the drill into the substrate, and (2) an outlet opening for the passage of material that is introduced for forming the foundation pile; and a flap that is movable between a first position for allowing unhindered screwing of the drill into the substrate and a second position for preventing the material from entering a screw groove. The screw groove is formed in the substrate by the screw blade during unscrewing of the drill from the substrate. The disclosure further relates to a method for forming a smooth foundation pile using such a drill.

The present disclosure relates to a soil displacement drill comprising a drill pipe; a widening at one end of the drill pipe that is provided with (1) a screw blade for screwing the drill into the substrate, and (2) an outlet opening for the passage of material that is introduced for forming the foundation pile; and a flap that is movable between a first position for allowing unhindered screwing of the drill into the substrate and a second position for preventing the material from entering a screw groove. The screw groove is formed in the substrate by the screw blade during unscrewing of the drill from the substrate. The disclosure further relates to a method for forming a smooth foundation pile using such a drill.

A method for the construction of composite under-reamed pile, including: implementing a jet grouting and agitation at a pre-designed position to form a composite cemented-soil foundation; constructing the pile hole with a drilling rig, during which bulb cavities are formed when the pile structure includes bulbs; cleaning the pile hole, lifting down a reinforcing cage, lowering a concrete pouring conduit to the pile hole, and lifting the pouring conduit while pouring the concrete; the hardened concrete becoming a pile stem in the pile hole and a bulb in the bulb cavity. Thus, this construction method can completely eliminate the hole collapse risk at the bulb cavity position during drilling; the combined structure of the bulb and the composite cemented-soil foundation can greatly improve the bearing capacity of pile foundation, significantly reduce the settlement risk and the cost of the pile foundation, as well as shorten construction period.

A method for the construction of composite under-reamed pile, including: implementing a jet grouting and agitation at a pre-designed position to form a composite cemented-soil foundation; constructing the pile hole with a drilling rig, during which bulb cavities are formed when the pile structure includes bulbs; cleaning the pile hole, lifting down a reinforcing cage, lowering a concrete pouring conduit to the pile hole, and lifting the pouring conduit while pouring the concrete; the hardened concrete becoming a pile stem in the pile hole and a bulb in the bulb cavity. Thus, this construction method can completely eliminate the hole collapse risk at the bulb cavity position during drilling; the combined structure of the bulb and the composite cemented-soil foundation can greatly improve the bearing capacity of pile foundation, significantly reduce the settlement risk and the cost of the pile foundation, as well as shorten construction period.

The friction pile system may include a steel pipe column, an auger spiraled around its exterior surface, a helical plate near the tip, and small structural elements located around the helix. A plurality of perforations may be provided on the pipe wall. The method of installation includes screwing the pipe assembly down into the ground by rotating it with a drivehead and simultaneously pressure injecting cement grout inside the pipe. The structural elements including weld beads maintain the bore hole created by the rotating helix and also guide grout to flow out though the perforations and upward along the auger while spreading outward filling in the hole. Thus the engineered pipe assembly leverages the mechanical energy of drilling to pressurize grout upward and outward improving bond with soil yielding high pile capacity.

The friction pile system may include a steel pipe column, an auger spiraled around its exterior surface, a helical plate near the tip, and small structural elements located around the helix. A plurality of perforations may be provided on the pipe wall. The method of installation includes screwing the pipe assembly down into the ground by rotating it with a drivehead and simultaneously pressure injecting cement grout inside the pipe. The structural elements including weld beads maintain the bore hole created by the rotating helix and also guide grout to flow out though the perforations and upward along the auger while spreading outward filling in the hole. Thus the engineered pipe assembly leverages the mechanical energy of drilling to pressurize grout upward and outward improving bond with soil yielding high pile capacity.

A system and method for installing an aggregate pier in a soil matrix includes a pipe configured to interface with a torque driver for rotating the pipe. A helix is disposed on the pipe and configured to advance/withdraw the pipe based on direction of rotation. A compacting device is disposed between the distal end of the pipe and the helix. It extends radially outward and upward. In some embodiments, the compacting device is configured as a frustum. A lift in an aggregate pier is formed by rotating the pipe in a second direction to withdraw a portion of the pipe from the soil matrix thereby creating a void; (b) filling the void with aggregate; (c) rotating the pipe in the first direction to advance the pipe. The compacting device contacts the aggregate disposed in the void and imparts an axial and radial force.

A system and method for installing an aggregate pier in a soil matrix includes a pipe configured to interface with a torque driver for rotating the pipe. A helix is disposed on the pipe and configured to advance/withdraw the pipe based on direction of rotation. A compacting device is disposed between the distal end of the pipe and the helix. It extends radially outward and upward. In some embodiments, the compacting device is configured as a frustum. A lift in an aggregate pier is formed by rotating the pipe in a second direction to withdraw a portion of the pipe from the soil matrix thereby creating a void; (b) filling the void with aggregate; (c) rotating the pipe in the first direction to advance the pipe. The compacting device contacts the aggregate disposed in the void and imparts an axial and radial force.

A hybrid foundation structure includes a first perforation hole formed in the ground, at least one second perforation hole formed adjacent to the first perforation hole on a side surface of the first perforation hole, and a first pile and a second pile formed by mixing and injecting soil and soil solidifying agent into the first perforation hole and the second perforation hole.

The invention relates to a working machine and a method for working the ground with the working machine, having a mast, along which, by means of a positioning means, a power rotary head is moved vertically, by which a telescopic Kelly rod having at least two Kelly bars is displaced and guided, wherein, for the purpose of torque transmission, the Kelly bars are provided on their external and/or internal sides with axially running drive keys as well as locking recesses on the drive keys and/or axial latch elements which are moved into the locking recesses for axially locking the Kelly bars or moved out of the locking recesses for unlocking. According to the invention provision is made in that by means of a control a locking state of the Kelly bars is checked automatically, wherein by the control the positioning means of the power rotary head and/or the main rope winch are actuated so that the Kelly bars are moved axially relative to each other, in that by means of a detection means a movement distance of the Kelly bars with respect to each other and/or an axial force during movement of the Kelly bars are axially detected, and in that depending on the detected movement distance and/or the detected axial force a locking state of the Kelly bars is ascertained by the control.