WO2015147628A1

WO2015147628A1 - Directional drilling machine

Info

Publication number: WO2015147628A1
Application number: PCT/MY2014/000234
Authority: WO
Inventors: Chee Pang LEE
Original assignee: Lee Chee Pang
Priority date: 2014-03-25
Filing date: 2014-09-17
Publication date: 2015-10-01
Also published as: CN203729876U; WO2015147628A8

Abstract

Disclosed is a directional drilling machine (10) comprising : a machine body (12) having a forward end (13); a directional drilling device (18) mounted on the body (12) and operable to extend a drill rod (38) away from the forward end (13) of the body (12); and a bearing member (30, 42) operable to extend away from the forward end (13) of the body (12) to engage and push against a surface (58) to counteract a pulling force applied by the drill rod (38) to the body (12).

Description

DIRECTIONAL DRILLING MACHINE

The present disclosure relates to a directional drilling machine .

BACKGROUND

Directional drilling machines are increasingly used for drilling operations in areas where space is limited - for example , urban areas .

To use a directional drilling machine a preliminary excavation must be made to form a launching pit so that the drill string (i.e. a number of drill rods connected in series) of the directional drilling machine can enter the ground in a predictable manner. The launching pit also acts as a sump or reservoir for drill mud and debris .

Current directional drilling operations thus typically require an excavator to prepare the launching pit in advance of the directional drilling machine being moved into position.

Once the preliminary excavation has been made the drilling machine is moved to the preliminary excavation and is anchored to the ground. Anchoring occurs in a number of ways, such as manually driving pickets through a ground anchor plate and into the ground, or by driving augers into the ground and attaching a ground anchor plate to the augers .

Augers loosen the ground as they are driven into it, and manually driving pickets into the ground is highly labour intensive. Moreover, neither method is practical in rocky ground. During the drilling operation, drill rods are fed into the drilling machine and are connected in series to form a drill string. Drill rods are generally long, heavy and not practical to manually handle . Cranes are currently used to feed drill rods into the machine to avoid the need for manual handling.

Current directional drilling operations that require a hole longer than the length of a single drill rod

therefore generally require a crane to be used in

conjunction with the drilling machine. And sufficient space must be provided around the machine to enable use of the crane. To avoid the need for a crane, a magazine can be used that connects to the drilling machine and loads a finite number of rods . For drilling operations longer than the combined length of the rods in the magazine, a similar issue arises as for machines that do not use magazines .

During back reaming and pull-back processes, the force applied by the drill system to the machine can be

sufficient to pull the machine towards the drill hole. Whether or not the machine will be pulled towards the drill hole is difficult to predict in advance since soil types vary substantially, resulting in significant

variation in the force with which the machine is anchored (e.g. using pickets or augers) to the ground. It is therefore desirable that there be provided a

directional drilling machine that is more simple and reliable to use on site .

SUMMARY

The present disclosure provides a directional drilling machine comprising: a machine body having a forward end;

a directional drilling device mounted on the body and operable to extend a drill rod away from the forward end of the body; and

a bearing member operable to extend away from the forward end of the body to engage and push against a surface to counteract a pulling force applied by the drill rod to the body. The surface may comprise a wall of a pit or a ground surface . The pit may be a launching pit for launching a drilling operation and the wall is the leading wall of the launching pit. In one embodiment, the bearing member pushes against the surface at a position directly above a position at which a drill rod enters the surface in use . In some cases the drill rod will comprise part of a drill string and the bearing member pushes against the surface at a position directly above a position at which the drill string enters the surface in use.

The bearing member may be attached to the body of the machine, and more particularly the bearing member may be attached to the drilling device.

Where the bearing member is attached to the drilling device it can be attached at a position directly above a line along which a drill rod passes through the drilling device.

The bearing member may comprise an extendable arm, which is preferably a boom. The boom may be a bucket arm, and could be hydraulically actuated. Hydraulic actuation may be afforded by one or more bucket cylinders. The power source (e.g. engine) for powering the drilling device may also be used to power the boom.

The bearing member may comprise a digger bucket, mounted to an end of the extendable arm, for pushing against the surface to counteract the pulling force applied by the drill rod to the body. The digger bucket may be operable to excavate a pit. The power source (e.g. engine) for powering the drilling device may also be used to operate the digger bucket. The digger bucket may be detachable . The digger bucket may be attached to the extendable arm by a hitch. The bearing member may comprise a ram for driving ground pegs into the ground. The power source (e.g. engine) for powering the drilling device may also be used to operate the ram. The ram may be attached to the boom by a hitch, where the hitch may be a quick hitch.

The bearing member may comprise a hook for lifting drill rods and the hook may be located on the boom, or could be located on the back of the digger bucket, or the hook may be located on the ram.

The bearing member may be mounted to the drilling device and may pivot on the drilling device about a pivot axis .

The bearing member may be pivotally mounted to a chair provided on the drilling device, where .the chair is a mounting seat .

The bearing member can also be adapted to engage various implements (e.g. a digger bucket or ram) can be directly mounted to the machine. This enables the directional drilling machine to perform excavation, pile driving and other unctions. As a result, the time, space and labour required to bring specialized machinery to site before and after drilling, and to assist the directional drilling machine during drilling is avoided. An operator's seat may be attached to the bearing member, where the operator's seat may be a rotating seat.

The axis about which the bearing member pivots may extend between the bearing member and operator's seat.

The axis about which the bearing member pivots may extend downwardly through a line along which a drill rod passes through the drilling device - in other words , the pivot axis of the bearing member may extend downwardly and intersect a longitudinal axis of the drill rod when the machine is in use.

The present disclosure also provides a directional

drilling machine comprising:

a machine body having a forward end;

a directional drilling device mounted on the body and operable to extend a drill rod away from the forward end of the body;

a ground anchor comprising:

a foot comprising a peg receiving member; and a ground engaging peg extendable through the peg receiving member and being adapted to be driven into ground by impact force and, once driven into the ground, to inhibit forward movement of the machine; and

a peg driver mounted on the machine for providing the impact force .

The term "impact" forces will be understood to include hammering forces , ramming forces and other types of impulse orces . The peg driver may comprise a ram and/or may comprise a hammer .

The drilling device may be powered by a power source that also provides power to the peg driver.

The ram mounted at or near the forward end of the body for driving the peg through the peg receiving member and into the ground.

The ram may be an hydraulic ram and may be mounted on a boom connected to the machine body or may be mounted on a boom connected to the drilling device. The machine may comprise a plurality of said ground engaging pegs where the ram is movable to drive each of the plurality of ground engaging pegs into the ground.

The foot may comprise a ground engaging plate that could have an elongate rectangular shape. The foot may extend transversely of the body, and may be mounted at or near an end of the directional drilling device .

The foot may extend transversely of the directional drilling device and be offset towards one side of the centre of the directional drilling device . In other words , the foot may extend further to one side of the directional drilling device than to the other side . The foot may alternatively extend an equal amount either side of a front end of the directional drilling device. The ^xfront end' is the end of the directional drilling device from which a drill rod projects during drilling. The foot may have a wedge-shaped cross-section. The wedge-shaped foot may narrow in the direction of the directional drilling machine. Furthermore, the wedge- shaped foot may thicken in the direction away from the directional drilling machine.

The peg receiving member may comprise an aperture for receiving a peg. The peg receiving member may retain the peg in fixed orientation relative to the foot. In other words, the longitudinal axis of the peg may be at a consistent angle relative to the foot.

The peg receiving member may allow the peg to be driven into the ground at a range of angles relative to the foot. The, or each, peg may be received in an aperture in the foot at a range of angles .

The aperture may comprise a ball joint including a ball and track, where the peg extends through the centre of the ball and the ball rotates in the track so that the peg is stably held by the foot at a range of angles .

The, or each, peg may be configured to be driven into the ground by a ram and may comprise a pile .

By enabling the pegs to secure through the foot and into the ground at a range of different angles , the angle of the pegs may be adjusted to suit a particular drilling operation. For example, the angles of the pegs may be adjusted in light of the slope of the ground, soil

conditions, and/or expected pull-back force.

The, or each, peg may comprise a hardened tip at the lower end of the peg. The lower end' is then end that is driven into the ground. A hardened tip reduces wear and the likelihood of damage if hard rocks are encountered as the peg is driven into the ground. The, or each, peg may be adapted to be driven into the ground by a ram or hammer and may comprise an upper end configured to be rammed by a ram, to drive the peg into the ground.

A retrieval member may be located at the upper end or intermediate the upper and lower ends to facilitate removal of the peg after use. The retrieval member may comprise an eyelet for engagement by a pin, the pin being pulled thereby to pull the peg from the ground. The pin may extend through corresponding apertures in a ram such that lifting the ram pulls the peg from the ground.

The retrieval member may comprise a wire loop, that is engageable by a hook operable to pull the peg from the ground.

The machine may comprise a plurality of pegs . Wire loops from multiple pegs may be receivable around the hook at one time, so that the hook can pull multiple pegs from the ground at the same time.

The pegs may be distributed at regular intervals along the foot. The pegs may be located (i.e. concentrated) at opposite ends of the foot.

The pegs may be positioned further away from the

directional drilling device on one side of the directional drilling device than the other.

The pivot axis of the bearing member may extend downwardly through an imaginary line extending through the centres of the pegs .

Pegs driven into the ground cause the ground around the peg to compress . Once the peg has been driven dully into the ground the hole formed by the peg pushes against the peg. This increases the force retaining the peg in the ground. Augers have a number of drawbacks when compared with the pegs of the present disclosure . An auger is rotated into the ground to form a helical cut in the ground. The helical cut loosens the ground around the auger. Also, augers tend to be very poor at cutting into rocky ground.

The present directional drilling machine may be a

horizontal directional drilling machine.

The present directional drilling machine may be a

trenchless directional drilling machine.

The present directional drilling machine may be a

trenchless horizontal directional drilling machine. The present directional drilling machine may be a

multifunction directional drilling machine. The

directional drilling machine may provide each of the functions of drilling, digging or excavating, pile- driving, pile extracting/retrieval , drill rod lifting and anchor pile supporting, or a subset or superset of those functions .

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings in which :

Figure 1 is a front perspective view of a directional drilling machine in accordance with the present invention, the drilling machine having a drill rod partially extended from the drilling device and an hydraulic ram connected to one of four anchor pegs;

Figure 2 is a side perspective view of the drilling machine of Figure 1 with a bucket replacing the ram, and showing the bucket lifting a drill rod;

Figure 3 is a front perspective view of the machine as shown in Figure 2 , with a lifting hook attached to the retrieval members (wire loops) of two ground engaging pegs ;

Figure 4 is a side view of the machine as shown in Figure 2, at commencement of excavation of a launching pit; and

Figure 5 is a side view of the machine as shown in Figure 2 , during simultaneous back reaming and pull-back

operations , with the hydraulic bucket counter-acting the pullback force .

DETAILED DESCRIPTION

As shown in Figure 1, a directional drilling machine 10 comprises a body 12 , operator cabin or operating room 14 and a power source presently embodied by an engine 16 located within the body 12. The machine 10 also comprises a directional drilling device 18 located to one side of the body 12. The directional drilling device 18 is adapted to extend a drill rod 38 away from a forward end 13 of the body 12 during drilling.

The general nature and construction of the body 12 , cabin 14, engine 16 and drilling device 18 will be understood by the skilled person.

The directional drilling machine further comprises a ground anchor, comprising ground anchor plate 20. The ground anchor plate 20 stabilises the front end of the drilling device 18 during drilling, back reaming and pull- back operations . The ground anchor 20 comprises a foot presently embodied by elongate, rectangular plate 22. The plate 22 is mounted to the front end of the drilling device 18. The ground anchor 20 resists forward motion of the directional drilling machine 10 during drilling, back reaming and pull-back operations. The ground anchor 20 also resists oscillation of the machine 10 about the axis X of the drilling device 18.

The plate 22 is offset to one side of the drilling device 18, which may assist in reducing oscillations in the machine 10. Oscillations may occur where, for example, a drill string 54 (comprising drill rod 38) encounters difficulty, such as hard rock or the collapsed of the borehole during a pull-back operation. In such cases the rotational force applied by the drilling device 18 may attempt to rotate the machine 10 about axis X.

The directional drilling device 18 is mounted to one side of the body 12. The weight of the body 12 is thus located predominantly to one side of the drilling device 18 and dampens oscillations on that side of the drilling device 18. Consequently, the plate 22 extends further from the drilling device 18 to the side opposite of the body 12 , to dampen oscillations on that opposite side of the body 12.

The plate 22 is secured to the ground by a plurality of pegs 24. Two pegs 24 are located at each end of the plate 22. Each peg 24 has a hardened, ground-piercing tip at its lower end. The upper end of each peg 24 is configured to be impacted by a longitudinally applied impact or 'ram' forces to drive the peg 24 into the ground. The ram forces are applied by a ram 26. Each peg 24 extends through a peg receiving member, presently embodied by aperture 28, in the foot 22. In some embodiments each aperture 28 may be configured so that the peg 24 extends through the aperture 28 in fixed

orientation. In other embodiments , each aperture 28 may be configured to allow a peg 24 to extend through the

aperture 28 in a range of orientations. For example, the aperture 28 may be slightly larger than the shaft of the peg 24, to enable the peg 24 to extend through the

aperture 28 at an angle.

In the present case, the pegs 24 are substantially

perpendicular to the plate 22. The pegs 24 are rammed or hammered into the ground. In so doing, the pegs 24 compress the ground around the holes made by the respective pegs 24. A reaction force applied by the ground to when trying to return to its previous position - in other words when trying to close the hole formed by the peg 24 - acts to retain the pegs 24 in the ground. This is to be contrasted with augers which cut the ground and result in no substantial compression. Instead, the cutting action loosens the ground and makes the augers comparatively more susceptible to inadvertent dislodgment during use .

The ram 26 is mounted, by a hitch 27, to a boom 30. The position of the ram 26 can be controlled by movements of the boom 30, to position the ram 26 above each peg 24 in turn. A single ram 26 is therefore capable of driving all of the pegs 24 into the ground.

An operator' s seat 34 is fixed to the boom 30 and both are pivotally mounted to a chair 32. The boom 30 and

operator's seat 34 are on opposite sides of a pivot axis Y that intersects a line Z through the centre of the pegs 24 - in the present example, the point of intersection of lines Y and Z is also at or near the point of intersection of line Y and axis X.

By locating the operator' s seat 34 on the opposite side of the pivot axis to the boom 30, the operator's line of sight is concurrently aligned with both the boom 30 and pegs 24. The ram 26 can therefore easily be aligned with the pegs 24 to drive the pegs 26 into the ground. The boom 30 and any implements attached to the boom 30 (e.g. the ram 26) are operable using controls at the operator's seat 34. Moreover, the boom 30 and implements attached to the boom 30 may be powered by the same power source (e.g. engine 16) that powers the drilling device 18.

Attached at a distal end of the boom 30 is a hook 36. The hook 36 can be used to lift slings and other pieces of equipment. As such, the hook 36 can be used to lift drill rods 38 as shown in Figure 2. The hook 36 may also be used to engage a retrieval member, presently embodied by wire loop 40, to lift the pegs 24 from the ground as shown in Figure 3. During drilling, the drill rods 38 are lifted by the hook 36 to attach to the drill string 54 and extend the length of the drill string 54. During withdrawal of the drill string 54 (e.g. in a pull-back or back reaming operation) the hook 36 lifts rods 38 off the drilling device 18 after disconnection of the rods 38 from the drill string 54.

By providing a hook 36 on the rear of the boom 30, the present drilling machine 10 avoids the need for a crane to be present on site to lift the drill rods 38. The hook 36 also avoids the need for a magazine which otherwise only enables a finite extension of the drill string before it too must be removed by crane. After the magazine is depleted, the crane is then required to install another magazine or to lift individual drill rods into place, for drilling to continue. The hook 36 may be provided at any suitable position on the boom 30 or on an implement attached to the boom 30 (e.g. ram 26 or digger bucket 42) .

The ram 26 is detachable from the boom 30 so as to enable the boom 30 to pick up other implements, such as digger bucker 42 as shown in Figure 4. The digger bucket 42 can then be used to excavate pits and stabilize the machine 10. Before commencing drilling it is often necessary to establish a launching pit 44 as shown in Figure 5. The launching pit 44 provides a site for entry of the drill string 54 into a surface (i.e. the ground) and also acts as a sump for drill mud and debris generated during drilling.

Previous directional drilling machines would be moved to site after excavation of a launching pit by an excavator. This can be hazardous, particularly for larger drilling machines where it is difficult to determine the location of the pit relative to the front of the machine when moving the machine towards the pit - in these instances a spotter may be used to communicate to the drilling machine operator the proximity of the drilling machine to the launching pit, but the spotter is an additional labour and time cost .

If the launching pit is inaccurately positioned, the angles of its walls are not well-formed, or the machine is not correctly located relative to the pit, then the stability of the directional drilling machine may be jeopardized. In contrast, when drilling machine 10 first arrives at a job site it can be set up (e.g. the ground anchor 20 can be fixed to the ground and any available jacks or

outriggers can be extended) in advance of the launching pit 44 being excavated. A digger bucket 42 is attached to the boom 30, which can then be controlled by an operator in the operator' s seat 34 to excavate the launching pit 44 as shown in Figure 4. Since the operator's seat 34 is located above, and very close to, the anchor plate 22 at the front of the drilling machine 10 it affords good visibility when excavating the pit 44. Rather than attempting to correctly and accurately position the drilling machine 10 at a pre-existing

launching pit, the launching pit 44 can be accurately excavated in an appropriate position relative to the drilling machine 10, or ground engaging plate 20 thereof, while the drilling machine 10 is in position for drilling. Once the launching pit 44 has been excavated, the drilling device 18 can be operated to drill the borehole 46 as shown in Figure 5. Oftentimes the borehole 46 is simply a pilot hole for a much larger hole 48 for accommodating large elongate objects such as conduit 50, pipes and similar. The larger hole 48 is formed by back reaming using a reamer 52 , and the conduit 50 is then pulled back through the reamed hole 48 - in other words a ^ull-back' operation is performed. The force required to pull the conduit 50 through the hole 48 can be very large, particularly where the hole 48 is unstable and partly collapsed. Occasionally, the force holding the ground anchor 20, and thus the drilling machine 10, in position is less than the force required to pull the conduit 50 back through the hole 48. In these circumstances the drilling machine 10 can be drawn towards the hole 48 rather than drawing the conduit 50 through the hole 48.

To resist inadvertent movement of the machine 10 towards the hole 48, the directional drilling machine 10 comprises a bearing member, presently comprising boom 30 and digger bucket 42 , operable to extend from the end of the body 12 , to engage and push against the ground to counteract a pulling force applied by the drill string 54 , through drill rod 38, to the body 12. As shown in Figure 5, the digger bucket 42 pushes against a surface, namely leading wall 58, of the launching pit 44.

Previously, to prevent movement of a directional drilling machine towards a borehole, the rear of the machine (i.e. the end opposite that at which the drill string extends from the machine) would be tethered to a tree or other structure. Tethering requires significant labour input and the availability of a suitable object to which to tether the machine .

Once tethered, the machine is pulled from both ends: force at one end is applied by the drill string and a reaction force is applied at the opposite end by the tether .

Pulling from both ends can cause the machine to lose stability and shift laterally - in other words, the machine may shift perpendicular to the longitudinal axis of the drill string or tether. To mitigate the risk of inadvertent lateral movements of the machine, the tether should be substantially

coextensive with the axis of the drill string. However, this can be very difficult to achieve. In directional drilling machines the directional drilling device is located to one side of the body, whereas the tethering point will typically be located centrally at the rear of the body. Thus the tether and axis of the drill string cannot be coextensive . As a resul , lateral movements of the directional drilling machine can occur, resulting in damage to the machine and drill rods . In contrast, the digger bucket 42 of the present drilling machine is located at the front of the drilling machine 10 near the drill string 5 . Since the bucket 42 and drill string 54 extend from the machine 10 in the same

direction, namely forwardly of the machine 10, the

likelihood of lateral deflection can be greatly reduced. This is because the drill string 54 and digger bucket 42 apply forces on the machine 10 at around the same

position. Therefore, a much larger force differential is required to shift the machine 10 when compared with a tether and drill string arrangement in which the moment arm between the tether and drill string is much longer.

Also, the digger bucket 42 needs only to be moved into position against the wall of the pit 44 whereas a tether must be unpacked and attached to both the machine and tree or other object. Consequently, the digger bucket 42 can greatly reduce the time required to stabilize the machine 10 during back reaming and pull-back operations . The bucket 42 is also mounted to a boom 30 the pivot axis Y of which extends directly downwardly through drill rod 38 of drill string 54. In other words, the boom 30, and thus the bearing member (comprising boom 30 and bucket 42) as a whole, is mounted in a position directly above a line A-A along which a drill rod 38 passes through the drilling device .

While the boom 30 may be offset to one side of line A-A, the absence of such an offset can enhance the stability of the machine 10, particularly during pullback and back reaming operations . As a consequence of the boom 30 being mounted above line A-A, an operator in the operator' s seat 34 can control the boom 30 to exactly horizontally align with the direction of extension of the drill string 54. In other words , the bucket 42 can be positioned against the wall of the pit 44 directly above the point of entry 56 of the drill string 54 into the wall 44. There is therefore no difference in horizontal position between the entry point of the drill string 54 into the wall 44, and the location of the digger bucket 42 against the wall 44 above that point of entry.

Accurate positioning of the bucket 42 in this manner can entirely prevent the creation of laterally acting forces between the bucket 42 and drill string 54 and similarly prevent lateral movements of the machine 10 as a result of those forces .

The boom 30 can be selectively attached to the ram 26, digger bucket 42 and any other implements as needed. The boom thus allows implements to be directly, and

interchangeably, mounted to the drilling machine. As a result, the drilling machine 10 can perform all of the necessary drilling, digging or excavating, pile-driving, drill rod lifting, pile extracting/retrieval and anchor pile support operations.

The drilling machine 10 as shown in the present figures avoids the need for support equipment and personnel such as an excavator, crane, or spotter. This reduces the burden on job scheduling. For example, there is no need for an excavator to be available and scheduled to dig the launching pit in advance of the arrival of the drilling machine. Also, the space necessary for performing a drilling operation can be reduced since there is no need to provide operating space for cranes and other equipment around the drilling machine during drilling. In the claims which follow and in the preceding

description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Malaysia or any other country.

Claims

1. A directional drilling machine (10) comprising:

a machine body (12) having a forward end (13) ;

a directional drilling device (18) mounted on the body (12) and operable to extend a drill rod (38) away from the forward end (13) of the body (12) ; and

a bearing member (30, 42) operable to extend away from the forward end (13) of the body (12) to engage and push against a surface (58) to counteract a pulling force applied by the drill rod (38) to the body (12) .

2. A machine (10) according to claim 1, wherein the bearing member (30, 42) pushes against the surface (58) at a position directly above a position (56) at which the drill rod (38) enters the surface (58) in use.

3. A machine (10) according to claim 1 or 2 , wherein the bearing member (30, 42) is attached to the drilling device (18) .

4. A machine (10) according to claim 3, wherein the bearing member (30, 42) is attached to the drilling device (18) at a position directly above a line (A-A) along which a drill rod (38) passes through the drilling device (18) .

5. A machine (10) according to any preceding claim, wherein the bearing member (30, 42) comprises an

extendable arm (30) .

6. A machine (10) according to claim 5, wherein the bearing member (30, 42) further comprises a digger bucket (42) , mounted to an end of the extendable arm (30) , for pushing against the surface (58) to counteract the pulling force applied by the drill rod (38) to the body (12) .

7. A machine (10) according to claim 5 or 6, wherein the digger bucket (42) is detachable.

8. A machine (10) according to any one of claims 5 to 7, wherein the extendable arm (30) includes a hitch (43) for attaching a ram (26) to the arm (30) , the ram being for driving ground pegs into the ground.

9. A machine (10) according to any preceding claim, wherein the bearing member (30, 42) comprises a hook (36) for lifting drill rods (38) .

10. A directional drilling machine (10) comprising:

a machine body (12) having a forward end (13) ;

a directional drilling device (18) mounted on the body (12) and operable to extend a drill rod (38) away from the forward end (13) of the body (12) ;

a ground anchor (20,22, 24, 28) comprising:

a foot (22) comprising a peg receiving member (28) ; and

a ground engaging peg (24) extendable through the peg receiving member (28) and being adapted to be driven into ground by impact force and, once driven into the ground, to inhibit forward movement of the machine (10) ; and

a peg driver (26) mounted on the machine (10) for providing the impact force .

11. A machine (10) according to claim 10, wherein the drilling device (18) is powered by a power source (16) that also provides power to the peg driver (26) .

12. A machine (10) according to claim 10 or 11, wherein the peg driver (26) is a ram (26) .

13. A machine (10) according to claim 12, wherein the ram (26) is mounted at or near the forward end of the body for driving the peg through the peg receiving member and into the ground.

14. A machine 10 () according to claim 13, wherein the ram (26) is mounted on a boom (30) connected to the machine body (12) .

15. A machine (10) according to any one of claims 10 to 14, comprising a plurality of said ground engaging pegs (24) .

16. A machine (10) according to claim 13 or 14,

comprising a plurality of said ground engaging pegs (24) , wherein the ram (26) is movable to drive each peg (24) into the ground.