WO2017004658A1

WO2017004658A1 - A device for forming a hole in a surface

Info

Publication number: WO2017004658A1
Application number: PCT/AU2016/000240
Authority: WO
Inventors: Tracey Boxsell
Original assignee: Cgb Engineering Pty Ltd
Priority date: 2015-07-03
Filing date: 2016-07-04
Publication date: 2017-01-12
Also published as: AU2016290884A1

Abstract

A device (1) for forming a hole in a surface, said device (1) comprising: a longitudinally extending frame (15) having a first end and a second end, said frame defining a longitudinal frame axis; a cutter head (2) operatively associated with said frame (15) and located adjacent said second end of said frame, said cutter head (2) configured in use to cut said hole in said surface; a drive means (13) configured in use to engage and drive said cutter head (2); and at least one conduit (5) extending between said first end and said second end of said frame (15), an inlet of said at least one conduit (5) positioned in use proximate said cutter head (2), said at least one conduit (5) configured to move liquid, gas, solids and/or a combination thereof through said conduit (5).

Description

A DEVICE FOR FORMING A HOLE IN A SURFACE

Field

[0001] The present invention relates to a device for forming a hole in a surface, and in particular to a device for forming a concrete pile.

Background

[0002] Retaining walls for multi-storey building foundations are constructed prior to excavation in order to prevent soil and/or water collapsing into the excavated site. Examples of such a retaining wall are bored pile retaining walls which are constructed from a series of adjacent concrete piles. A concrete pile is generally formed by drilling a hole into the ground and subsequently filling the hole with concrete.

[0003] Commonly used bored pile retaining walls include contiguous, tangent and secant pile walls. Contiguous pile walls are constructed with a gap between adjacent concrete piles.

Tangent pile walls differ from contiguous pile walls in that there are no gaps between adjacent concrete piles. Secant pile walls are constructed with concrete piles which intersect with adjacent concrete piles.

[0004] Contiguous Fl ight Auger (CFA) rigs are commonly used in the construction of bored pile retaining walls to form a single concrete pile. A CFA rig essentially comprises an auger (drill) with a hollow shaft. The auger is used to drill a hole to a predetermined depth while

simultaneously removing earth from the hole. Once the hole has been formed, concrete is pumped through the hollow shaft of the auger as it is being withdrawn from the hole. While concrete is setting in a hole it is not possible to drill a further hole immediately adjacent to it as the concrete is not stable. Accordingly, bored pile retaining walls are typically constructed in three sequences (primary, secondary and tertiary) when using a CFA rig.

[0005] Referring to Figure 1 , during the primary sequence, a series of concrete piles are formed with a space of approximately twice the diameter of the concrete piles between adjacent primary sequence piles. On completion of the primary sequence, secondary sequence piles are formed to one side of the primary sequence piles thereby leaving a space of approximately the diameter of the concrete piles between the secondary sequence piles and the next primary sequence pile. On completion of the secondary sequence, tertiary sequence piles are formed in the spaces between the secondary and primary sequence piles thereby completing the bored pile retaining wall.

[0006] Accordingly, this is a time consuming process as three sequences of piles must be formed and the CFA rig must be moved before forming the next concrete pile. This also increases costs and time delays on site during construction. It will be appreciated that this issue will be exacerbated when there are a large number of concrete piles to be formed. When the round piles are hollowed out for the car park (for example) under a building the new wall will be straight, not cylinder shapes.

[0007] Accordingly, there is a need to address the above by providing a device that can reduce the total number of sequences and holes required to construct a bored pile retaining wall which reduces the number of rig moves and alignments.

Object of the Invention

[0008] It is the object of the present invention to address the above need, or to at least provide a useful alternative.

Summary of Invention

[0009] An aspect of the present invention provides a devi ce for forming a hole in a surface, said device comprising:

a longitudinally extending frame having a first end and a second end, said frame defining a longitudinal frame axis;

a cutter head operatively associated with said frame and located adjacent said second end of said frame, said cutter head configured in use to cut said hole in said surface;

a drive means configured in use to engage and drive said cutter head; and

at least one conduit extending between said first end and said second end of said frame, an inlet of said at least one conduit positioned in use proximate said cutter head, said at least one conduit configured to move liquid, gas, solids and/or a combination thereof through said conduit. [0010] Preferably, an outlet of said at least one conduit being connected to a vacuum source, said vacuum source configured to move liquid, gas, earth and/or a combination thereof through said at least one conduit.

[0011] Preferably, said cutter head is configured in use to rotate about an axis at least substantially perpendicular to said longitudinal frame axis.

[0012] Preferably, said cutter head comprises cutting elements disposed on a surface of said cutter head, said cutting elements configured to cut said hole in said surface.

[0013] Preferably, said cutting elements are a plurality of cutting projections extending from said surface of said cutter head.

[0014] Preferably, said frame is watertight to prevent the ingress of water into an interior of said frame.

[0015] Preferably, at least a portion of said first end of said frame is configured to allow air to enter into said interior of said frame.

[0016] Preferably, said device further comprises a support coupled to said frame, at least a distal end of said support disposed adjacent to and external said second end of said frame.

[0017] Preferably, said drive means is supported on said support.

[0018] Preferably, said drive means comprises a drive train supported by said support, said drive train configured to engage and drive said cutter head.

[0019] Preferably, said drive train engages said cutter head adjacent said distal end of said support.

[0020] Preferably, said support is configured in use to allow said cutter head to move laterally during cutting of said hole in said surface.

[0021] Preferably, said support is configured in use to allow said cutter head to move laterally in a first direction and a second direction. [0022] Preferably, said first direction is opposite said second direction.

[0023] Preferably, said support is pivotably coupled to said frame to allow said cutter head to move laterally in said first and second directions.

[0024] Preferably, said support is pivotably coupled proximate said first end of said frame.

[0025] Preferably, said device further comprises an actuating means having a first end coupled to said frame and a second end coupled to said support, wherein advancing said actuating means pivots said support in said first direction and retracting said actuating means pivots said support in said second direction.

[0026] Preferably, said device further comprises at least one further conduit extending between said first end and second end of said frame, an inlet of said at least one further conduit positioned in use proximate said cutter head.

[0027] Preferably, said at least one further conduit is configured in use to inject concrete into said hole.

[0028] Preferably, an outlet of said at least one further conduit being connected to a concrete source to inject concrete into said hole.

[0029] Preferably, said outlet of said at least one conduit and said outlet of said at least one further conduit being configured in use to be connectable to a vacuum source during cutting of said hole and a concrete source to inject concrete into said hole.

[0030] Preferably, a trowel frame is coupled to said second end of said frame, said trowel frame providing clearance for inserting said frame into and withdrawing said frame from said hole.

[0031] Preferably, said trowel frame is disposed above and surrounds said cutter head.

[0032] Preferably, said trowel frame comprises at least one bearing, said at least one bearing configured in use to limit and guide said lateral movement of said support. [0033] Preferably, a flexible material is disposed within said trowel frame, said flexible material separating an interior of said trowel frame into a first section and a second section, said first section being sealed from said second section.

[0034] Preferably, said flexible material comprises at least one valve, said at least one valve allowing air to flow from said first section to said second section.

[0035] Preferably, said at least one valve is a one-way valve to allow air to flow from the first section to the second section.

[0036] Preferably, a seal is disposed between said trowel frame and said second end of said frame, said seal configured in use to contact a side wall of said hole.

[0037] Preferably, said seal is a bentonite or stabilising solution seal.

[0038] Preferably, said drive means is a hydraulic motor.

[0039] Preferably, said actuating means is a hydraulic ram.

[0040] Preferably, said frame is configured to allow a further frame to be stacked thereon. Brief Description of Drawings

[0041] A preferred embodiment of the invention will be described hereinafter, by way of an example only, with reference to the accompanying drawings:

[0042] Figure 1 illustrates the method of forming a bored pile retaining wall or foundation piers using a CFA rig;

[0043] Figure 2 is a front section view of a device for forming a concrete pile in accordance with an embodiment of the present invention;

[0044] Figure 3 is a front section view of the device of Figure 1 cutting a hole;

[0045] Figure 4 is front section view of the device of Figure 1 injecting concrete into the hole while the device is being withdrawn from the hole; [0046] Figure 5 is a comparison of a concrete pile fonned in accordance with an embodiment of the present invention compared to three concrete piles formed using a CFA rig; and

[0047] Figure 6 shows the cutting sequences for forming a bored pile retaining wall in accordance with an embodiment of the present invention.

Description of Embodiments

[0048] Referring to Figure 2, an embodiment of a device 1 for forming a concrete pile is shown. The device 1 includes a frame 15 which is water tight to prevent the ingress of water into the interior of the frame. The top of the frame 15 is configured to allow air to enter the interior of the frame 15. A centre support 4 is disposed within and coupled to the frame 15 by a pivot support 14. An end portion 16 of the centre support 4 extends through the base of the frame 15. The pivot support 14 allows the centre support 4 to pivot laterally such that the end portion 16 moves at least a di stance of half the width "d" of the end portion 16 in either direction.

[0049] A cutter head 2 is disposed adjacent the end portion 16 of the centre frame 4. The cutter head 2 has a plurality of cutting elements 3 extending from and normal to the surface of the cutter head 2 (only one cutting element is labelled for clarity of illustration), trenching cutters, rock picks or tungsten cutters depending upon ground conditions. The cutter head 2 is configured to rotate about the axis labelled XX. The end portion 16 of the centre support 4 creates a region having a width "d" where the cutter head 2 cannot cut, this region is referred to hereinafter as "the cutting blind spot". The pivot support 14 allows the cutter head 2 to move laterally in either direction in order to reach the cutting blind spot thereby cutting a hole that is wider than the cutter head 2.

[0050] A drive means 13 in the form of a hydraulic motor is supported on the centre support 4. The drive means 13 is coupled to the cutter head 2 via a drive train 19 (see Figure 3). The drive train 19 comprises sprockets 20, 21 coupled to each of the dri ve means 13 and the cutter head 2, and a chain 22 engaging both sprockets 20, 21. It will be appreciated that the drive means 13 could also be any means suitable for rotating the cutter head 2, such as, for example, electric or pneumatic motors and the like. The drive train 19 can also be any other suitable means known in the art for coupling the drive means 13 to the cutter head 2. [0051] Conduits 5 extend through the frame 15 with a first end of the conduits 5 positioned above the cutter head 2 and on either side of the centre support 4, and a second end of the conduits 5 exiting through the top of the frame 15. While cutting a hole, the second ends of the conduits 5 are connected to an industrial vacuum such as the "VacTrax" offered by CGB Services Pty Ltd. After the hole has been cut, the second ends of the conduits 5 are connected to a concrete source to pump concrete through the conduits 5 and into the hole. It will be appreciated that a separate group of conduits can be provided for pumping concrete into the hole and for removing earth, air and/or water from the hole.

[0052] A lateral actuating means 8 in the form of a hydraulic ram is provided to pivot the centre support 4 laterally in either direction. The lateral actuating means 8 includes an actuating cylinder 10 pivotably coupled to frame lug 9 and an actuating rod 1 1 pivotably coupled to centre support lug 12. Advancing and retracting the actuating rod 1 1 will pivot the centre support 4 in either direction thereby moving the cutter head 2 so that it can reach the cutting blind spot. It will be appreciated that any other suitable means known in the art can be utilised as the lateral actuating means 8, such as, for example, pneumatic or electric means.

[0053] A trowel frame 6 is coupled to the bottom of the frame 15. The trowel frame 6 is positioned above and surrounds the cutter head 2. The trowel frame 6 has a width of at least that of the cutter head 2 and the width "d". The trowel frame 6 provides clearance for inserting the frame 15 into the hole while cutting the hole and when withdrawing the frame 15 from the pile hole.

[0054] There is at least one bearing (not shown in the figures) disposed in the trowel frame 6. The at least one bearing guiding and limiting the lateral movement of the centre support 4 when the lateral actuating means 8 is advanced and retracted.

[0055] Referring to Figure 3, disposed within the trowel frame 6 is a flexible seal 17. The flexible seal 17 is coupled to the interior of the trowel frame 6, around the first ends of the conduits 5 and the centre support 4. The flexible seal 17 separating the interior of the trowel frame 6 into an upper section and a lower section. The flexible seal 17 sealing the upper section from the lower section. The cutter head 2, end portion 16 of the centre support 4 and the first ends of the conduits 5 being disposed below the flexible seal 17. The flexible seal 17 configured to allow lateral movement of the centre support 4 while maintaining a seal between the upper section and lower section of the trowel frame 6.

[0056] The flexible seal 17 comprises check valves 18. During cutting of the hole, the check valves 18 are open as a result of the pressure differential generated from the vacuum source connected to the conduits 5. When the check valves are open, air passes from the upper section of the trowel frame 6 to the lower section. The incoming air passes through the check valves 18 and over the cutter head 2, thereby cleaning the cutter head 2, before the incoming air is sucked up through the conduits 5. The flow rate of air over the cutter head 2 is important. This detennines the velocity of air and volume of product removed. It creates a direction from outside edges of the hole towards the centre for product movement. As concrete is pumped through the conduits 5, the concrete fills the hole and the lower section of the trowel frame 16 thereby forcing the check valves 18 shut. When the check valves are shut the upper section of the trowel frame 16 is completely sealed from the lower section.

[0057J Disposed between the frame 15 and the trowel frame 6 is a sealing element 7 in the form of a bentonite or stabilising solution to stabilise the walls of the hole during the cutting process. The dimensions of the sealing element 7 in a horizontal plane are greater than those of the trowel frame 16. During cutting of the hole the free ends of the sealing element 7 contact the sidewalls of the hole and are directed upwards. When withdrawing the device 1 from the hol e the free ends of the sealing element contacting the sidewalls of the hole invert such that they are directed downwards. In use the sealing element 7 separates and seals the hole into two sections with one section being above the sealing element 7 and the other section being below. The sealing element 7 thereby prevents concrete leaking past the trowel frame 6 when concrete is injected into the hole.

[0058] The frame 15 is modular and is configured to permit vertical coupling of further frame 15 modules thereon. The depth of the pile hole that needs to be drilled determines the number of frame 15 modules that must be coupled to each other.

[0059] During operation, the device is coupled to a drill rig, the drill rig being controlled by a drilling operator. The drill rig is configured to advance the device during cutting of the hole. The drill rig is further configured to withdraw the device 1 from the hole after the hole has been cut. [0060] Figure 3 shows the device 1 cutting a hole. The drive means 13 coupled to the cutter head 2 via drive train 19 rotates the cutter head 2 about the axis labelled XX to cut the hole. During cutting of the hole, the conduits 5 are connected to a vacuum source thereby removing air, earth and/or water from the hole. During this process the check valves are open thereby allowing air to pass over the cutter head 2 before being sucked up conduits 5. The cutter head 2 is moved laterally in either direction to reach the cutting blind spot by advancing and retracting the lateral actuating means 8. This process continues while the drill rig advances the device 1 until a predetermined depth has been reached.

[0061 ] Figure 4 shows the device 1 injecting concrete into the hole. After the hole has been cut, the second ends of the conduits 5 are disconnected from the industrial vacuum and connected to a concrete source. Concrete is then pumped through the conduits 5 and into the hole thereby filling the hole. The concrete forces the check valves 18 closed which seals the upper section of the trowel frame 6 from the lower section. As concrete is pumped into the hole, the concrete in the hole pushes up on the device 1 which indicates to the drilling operator that the device 1 should be withdrawn. This process continues until the hole has been filled with concrete and the device 1 has been completely withdrawn from the hole.

[0062] Figure 5 is a comparison of a concrete pile 23 formed in accordance with an embodiment of the present invention compared to three concrete piles 24 formed using a CFA rig. The width of the concrete pile 23 is the equivalent of three immediately adjacent concrete piles 24. It will be appreciated that the width of the cutter head 2 can be varied to form holes of varying dimensions. Therefore, according to an embodiment of the present invention, fewer holes need to be formed in order to construct a bored pile retaining wall in comparison to the prior art.

[0063] Unlike the prior art, the device according to an embodiment of the present invention forms a bored pile retaining wall having straight walls which provides greater strength in comparison to bored pile retaining walls of the prior art. Accordingly, the concrete piles 23 formed in accordance with an embodiment of the present invention do not need to be formed as deep as concrete piles 24. This may, therefore, result in less concrete being used to form a bored pile retaining wall compared to the prior art. There is provided less rig moves, less alignments and better finish. [0064] Figure 6 illustrates the cutting sequences required to form a bored pile retaining or foundation wall in accordance with an embodiment of the present invention. As clearly illustrated, according to an embodiment of the present invention, fewer sequences of concrete piles 23 need to be formed in order to construct a bored pile retaining wall in comparison to the prior art.

[0065] Although the invention has been described with reference to a specific example, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Claims

1. A device for forming a hole in a surface, said device comprising:

a drive means configured in use to engage and drive said cutter head; and

at least one conduit extending between said first end and said second end of said frame, an inlet of said at least one conduit positioned in use proximate said cutter head, said at least one conduit configured to move liquid, gas, solids and/or a combination thereof through said conduit.

2. The device of claim 1, further comprising an outlet of said at least one conduit being connected to a vacuum source, said vacuum source configured to move liquid, gas, earth and/or a combination thereof through said at least one conduit.

3. The device of claim 1 or 2, wherein said cutter head is configured in use to rotate about an axis at least substantially perpendicular to said longitudinal frame axis.

4. The device of any one of the preceding claims, wherein said cutter head comprises cutting elements disposed on a surface of said cutter head, said cutting elements configured to cut said hole in said surface.

5. The device of claim 4, wherein said cutting elements are a plurality of cutting projections extending from said surface of said cutter head.

6. The device of any one of the preceding claims, wherein said frame is watertight to prevent the ingress of water into an interior of said frame.

7. The device of any one of the preceding claims, wherein at least a portion of said first end of said frame is configured to allow air to enter into said interior of said frame.

8. The device of any one of the preceding claims, further comprising a support coupled to said frame, at least a distal end of said support disposed adjacent to and external said second end of said frame.

9. The device of claim 8, wherein said dri ve means is supported on said support.

10. The device of claim 9, wherein said drive means comprises a drive train supported by said support, said drive train configured to engage and drive said cutter head.

11. The device of claim 10, wherein said drive train engages said cutter head adjacent said distal end of said support.

12. The device of claim 11 , wherein said support is configured in use to allow said cutter head to move laterally during cutting of said hole in said surface.

13. The device of claim 12, wherein said support is configured in use to allow said cutter head to move laterally in a first direction and a second direction.

14. The device of claim 13, wherein said first direction is opposite said second direction.

15. The device of claim 14, wherein said support is pivotably coupled to said frame to allow said cutter head to move laterally in said first and second directions.

16. The device of claim 15, wherein said support is pivotably coupled proximate said first end of said frame.

17. The device of any one of claims 8 to 16, wherein said device further comprises an actuating means having a first end coupled to said frame and a second end coupled to said support, wherein advancing said actuating means pivots said support in said first direction and retracting said actuating means pivots said support in said second direction.

18. The device of any one of the preceding claims, wherein said device further comprises at least one further conduit extending between said first end and second end of said frame, an inlet of said at least one further conduit positioned in use proximate said cutter head.

19. The device of claim 18, wherein said at least one further conduit is configured in use to inject concrete into said hole.

20. The device of claim 19, further comprising an outlet of said at least one further conduit being connected to a concrete source to inject concrete into said hole.

21. The device of claim 20, wherein said outlet of said at least one conduit and said outlet of said at least one further conduit being configured in use to be connectable to a vacuum source during cutting of said hole and a concrete source to inject concrete into said hole.

22. The device of any one of the preceding claims, further comprising a trowel frame coupled to said second end of said frame, said trowel frame providing clearance for inserting said frame into and withdrawing said frame from said hole.

23. The device of claim 22, wherein said trowel frame is disposed above and surrounds said cutter head.

24. The device of claim 22 or 23, wherein said trowel frame comprises at least one bearing, said at least one bearing configured in use to limit and guide said lateral movement of said support.

25. The device of any one of the preceding claims, further comprising a flexible material disposed within said trowel frame, said flexible material separating an interior of said trowel frame into a first section and a second section, said first section being sealed from said second section.

26. The device of claim 25, wherein said flexible material comprises at least one valve, said at least one valve allowing air to flow from said first section to said second section.

27. The device of claim 26, wherein said at least one valve is a one-way valve to allow air to flow from the first section to the second section.

28. The device of any one of the preceding claims, further comprising a seal is disposed between said trowel frame and said second end of said frame, said seal configured in use to contact a side wall of said hole.

29. The device of claim 28, wherein said seal is a bentonite or stabilising solution seal.

30. The device of any one of the preceding claims, wherein said drive means is a hydraulic motor.

31. The device of any one of the preceding claims, wherein said actuating means i s a hydraulic ram.

32. The device of any one of the preceding claims, wherein said frame is configured to allow a further frame to be stacked thereon.