GB2139671A

GB2139671A - Drilling devices

Info

Publication number: GB2139671A
Application number: GB08316396A
Authority: GB
Inventors: Mordechai Yuger
Original assignee: LIPSKER ENG
Current assignee: LIPSKER ENG
Priority date: 1983-01-12
Filing date: 1983-06-16
Publication date: 1984-11-14
Also published as: GB2139671B; GB8316396D0

Abstract

In the drilling of bore holes the soil is simultaneously consolidated and/or stabilized by increasing the width of the drilling tool, eg. by providing the tool in parts 17 arranged in conjunction with mechanical or other means 18, to move away from each another to exert pressure. <IMAGE>

Description

SPECIFICATION Drilling devices This invention relates to soil drills and excavating tools and more particularly to drills of the Auger Bucket Type and to digging grabs.

The invention further relates to a method of producing bore shafts in the ground.

As is known bore shafts of smaller or greater depth, both vertical and horizontal ones, as well as such extending obliquely to the soil surface are made for various purposes, such as piling, tunnelling and many more. One of the problems encountered by those who work in this field is the caving in of a shaft, either while work is still in progress or whenever the drilling tool is withdrawn, either periodically during progress of work or after completion thereof. For that reason, i.e. in order to prevent a cave in, especially in cases of light and sandy soil, the walls of the shaft have to be safeguarded by lining, as is done e.g. in tunnelling operations or by introduction of mud as is conventionally practised.

Obviously, such steps, preventing cave in have to be performed after withdrawal of the respective tools, which means that at those times drillings stops, or work has to be slowed down considerably in the case of mud being introduced while drilling.

All this obviously lengthens the period of time required for the production of a bore and also considerably increases the cost of the work.

It is the main object of this invention to provide a device which performs simultaneously the actual drilling and the consolidation and stabilization of the soil forming the wall of the bore, thus accelerating the progress of the operation and reducing the cost thereof.

According to the invention there are provided tools (which may be of bucket type or digging grabs) which comprise at least two plate shaped parts and means adapted to cause the said two parts to move away from one another and thus exert pressure onto the wall of the bore hole. The said plate shaped parts are curved when used on a bucket type auger and plane if used on a grab.

The means for bringing about the said movement may be either mechanical, pneumatic or hydraulic ones.

According to an embodiment of the invention, the auger is of the split type, the bucket comprising two or more parts which are so connected that they can be moved apart and thus exert pressure on the wall of the bore shaft consolidating the latter and preventing a cave in.

According to another embodiment of the invention, an auger is enclosed by a number of - at least two -- curved plates which perform the consolidation of the bore hole wall.

In case of a grab, plane plates are provided at the opposite, flat sides of the grab.

In an advantageous embodiment of the invention, as applied to an auger device, the said curved plates are connected with the auger itself by a number of tension springs, which - after actuation of the means pressing the plates towards the wall of the bore hole and after release of the pressure return the plates to their normal position, close to the cylindrical surface of the auger.

According to yet another embodiment ring shaped members which are slipped on the auger and which rings comprise at least two parts and are pressed by the crosswise expansion of the auger onto the wall of the bore hole to form a lining thereof. In the latter case the auger is periodically withdrawn from the bore hole and fresh rings are placed thereof, as the work proceeds.

In the case of tunnelling jobs, the auger need not always be withdrawn, instead the rings are fed onto the auger from the rear, while soil is removed therefrom by a conveyor.

By the means referred to the bore hole wall is consolidated and cave in may be prevented, but - in addition -- and in certain cases most importantly, the bore hole could be widened which means that relatively wide bore holes could be produced by smaller and weaker rigs as heretofore, i.e. by drilling equipment which conventionally could produce only bores of smaller diameter.

Bore holes produced with the aid of the new device may extend strictly vertically or horizontally or obliquely.

In certain cases, where there is no immediate likelihood of cave in but such occurrence could be expected at some later time, it could be preferable or advantageous to first drill the bore hole and only after termination of that step - or whenever a certain depth has been reached - to consolidate the wall of the hole and possibly widen it.

Tools for dealing with such a contingency may be used in combination with the tools which are the main subject of this invention, There is provided an auxiliary device constituted by at least two inter-connected plates enclosing a space between them in which space are positioned means for moving the plates apart, such means being actuated hydraulically or pneumatically or mechanically.

In a practical embodiment, the new auxiliary device comprises a number of slightly curved plates which together define a cylindrical body within which a number of piston-incylinder means are positioned for moving the plates apart from one another.

Alternatively, the new device may be constituted by at least two plane plates which are positioned at a distance from one another, the said piston-in-cylinder means being accommodated within the space between the plates.

The bore holes so produced may be part of different kinds of work but most advantageously will serve in piling work. It is possible to make certain portions of a bore hole - say the lower region thereof -- wider than the rest, and cast the pile in that wider portion.

Alternatively - and depending on the kind of soil in a particular job the bore hole would be tapering downwardly, thus making it possible to produce tapering piles or like formations.

Moreover, consolidation of the bore hole wall improves the soil parameters and increases the bearing capacity of the piles.

The invention will now be described in detail in connection with the attached drawings which illustrate by way of example tools incorporating the improvement of the present invention.

In the drawings Figures 1 and 2 are schematical, perspective views of a bucket auger and of a digging grab respectively.

Figures 3-6 are cross sectional, horizontal, sections of different embodiments of the invention, applied to bucket type augers.

The auxiliary devices referred to are shown in Figs. 7-12.

Figure 7 shows the new device in cylindri cal shape, while Figure 8 is the device constituted by two plane plates.

Figure 9 shows the new device mounted on top of an auger.

Figure 10 is a top view of the devices shown in Figs. 1 and 3.

Figure 11 is a top view of the device shown in Fig. 2, and Figure 12 is a device similar to tha of Fig. 1 but equipped with an additional tool.

For a better understanding of the gist od this invention, reference is first had to the conventional tools shown in Figs. 1 and 2.

The bucket type auger of Fig. 1 is of the plate enclosed kind. It comprises a body parts a and lateral closing plates b. The actual drilling is performed by two or more cutters d at the bottom of the bucket. As drilling proceeds removed soil rises in the bucket which has to be lifted periodically to the surface for emptying it.

The drilling grab shown in Fig. 2 comprises two shovels m and n which depend from a box shaped body C. The two shovels m and n swing about their hinges h. They are usually provided with cutters or teeth t The shovels m and n open to opposite directions and when closing again gather ("grab") a portion of the soil into which the tool digs. The digging grab is also lifted to the surface for emptying.

Turning now to Fig. 3, there is shown in a cross sectional view a bucket type auger comprising four arch shaped segments 1, 2, 3, 4 which are interconnected by four crosswise grouped hydraulic cylinders 5, 6, 7, 8 extending from a central shaft 9. The said cylinders are positioned within guide rails 10, 11, 12, 1 3 which extend from the inner face of segments 1, 2, 3, 4.

This auger is worked in the customary way, is periodically lifted to the surface for emptying and cleaning. In order to consolidate the wall of the bore hole the hydraulic cylinders are operated via a conduit supplying pressure fluid with the effect of moving the segments 1, 2, 3, 4 away from the centre and exerting lateral pressure on the bore hole wall.

The auger shown schematically in Fig. 4 is of conventional build and comprises two halves 14, 15.

To each of the semi circular halves 14, 1 5 are connected via springs 1 6, crescent shaped plates 1 7. Interposed between the auger halves 14, 1 5 and the respective plate are inflatable bodies 1 8. This auger is also worked in the conventional manner; whenever required the inflatable bodies 1 8 are put under pressure and inflated, thereby pressing the plates onto the wall of the bore hole and consolidating the soil. When pressure is released, the bodies 1 8 become deflated and the plates 1 7 are retracted onto the auger.

In Fig. 4 the right hand part of the auger is shown in position of drilling, i.e. with plates 1 8 close to the auger. The left hand part of Fig. 4 shows the plates 1 7 being pressed onto the wall of the bore hole by means of the inflated bodies 18.

According to Fig. 5, the plates 1 7 carry ring segments, which in - the manner described in connection with Fig. 4 - are pressed into the soil of the bore hole wall and remain there, lining the latter.

The construction of Fig. 6 also uses the ring segments, but in this case they are carried on segments forming the auger proper, as described in connection with Fig. 3.

The use of equivalent plates on grabs, according to Fig. 2 is obvious and needs no detailed description. Suffice it to say that plane plates are connected to and carried on the plane sides of the grab in the one of the manners described with reference to Figs.

3-6.

Turning now to Fig. 7, the new device comprises four curved plates 20, which are interconnected by a cross of four piston-incylinder tools 21 (see Fig. 4), which are held on a square profiled bar 22 positioned at the centre of the cylinder formed by the plates 20. The cylinders of the tools 21 are affixed to the bar 22 while the piston rods 21a are attached to plates 21. Similarly, the plates 23 shown in Fig. 8 are inter-connected by a telescoping connection 24, while two pistonin-cylinder tools 25 extend between the two plates (Fig. 11).

The devices of Fig. 7, Fig. 8 or Fig. 11 are passed in a bore hole. The piston-in-cylinder tools 21 or 25 are actuated by pressure fluid supplied from the top through a conduit enter ing the respective cylinder. Due to this the pistons move outwardly of the cylinders, so that the plates 20 or 23 are pressed against the wall of the bore hole and consolidate the ground. These devices of Figs. 7 and 8 are employed in those cases where the bore hole has reached a certain depth and the auger, or grab -- whatever had been used - have been withdrawn.

According to Fig. 9 the new device is mounted on top of an auger of bucket type, designated by the numeral 25. The function of the auger need not be described, but whenever desired, drilling may be stopped temporarily and the new device -- here designated as a whole by the numeral26 may be actuated. It then functions in the manner described.

It goes without saying that a device as shown in Fig. 8 may be mounted on the digging tool, possibly on top of a grab.

Turning finally to Fig. 12, there is shown a device as that of Fig. 7 but including a pressure plate 27 which is actuated by a piston-in-cylinder tool 28 which latter is positioned coaxially with the device as a whole.

This latter arrangement serves for compacting the bottom of a bore hole whenever desired.

Usually the pressure plate 27 will be actuated after plates 20 are pressed against the bore hole walls.

As has been stated, the main ourpose, or one of the purposes of the new devices is compacting and consolidating the soil forming the wall and/or bottom of a bore hole. However, the same devices -- used independently of a digging tool - will serve also as a load test to indicate the nature, i.e. density and compactness of soil strata by registering the resistance of the soil at certain locations to the movement of the pistons towards the ground.

So, the device of Fig. 7 may be used only for compacting the soil or only for measuring its resistance to pressure. The device of Fig. 9 will be used for digging, temporarily stopping the digging and consolidating, compacting and/or measuring density or compactness of different strata, as the work progresses.

All instruments when serving in both functions as a consolidating device or as a load test device can be equipped with conventional measuring devices to accurately indicate the amount of expansion of the device versus the pressure applied.

Claims

1. Method of drilling bore holes and simultaneously consolidating and/or stabilizing the soil at the bore hole wall by increasing the width of the drilling tool used.

2. Method according to claim 1 in which the bore hole is lined during the drilling by forcing ring segments into the soil of the bore hole wall.

3. In the method of drilling, as claimed in either of claims 1 or 2 in which the bore hole is made partly flaring in downward direction.

4. In the method of drilling, as claimed in claim 1, making the bore hole partly tapering in downward direction.

5. Soil drilling tools for use in the method of any one of claims 1 to 4 characterised by comprising at least two parts to move away from one another and thus exert pressure onto the wall of the bore hole.

6. Soil drilling tool as claimed in claim 5 being a bucket type auger characterised by being provided with at least two curved plates and means adapted to cause the said two parts to move away from one another and thus exert pressure onto the wall of the bore hole.

7. Soil drilling tool as claimed in either of claims 5 or 6, being a digging grab characterised by being provided with at least two plane plates and means adapted to cause the said two parts to move away from one another and thus exert pressure onto the wall of the bore hole.

8. Soil drilling tools as claimed in claim 5 or 6 or 7, characterised thereby that the means for bringing about the said movement are conventional mechanical means.

9. Soil drilling tools as claimed in claim 5 or 6 or 7, characterised thereby that the means for bringing about the said movement are conventional pneumatic means.

10. Soil drilling tools as claimed in claim 5 or 6 or 7, characterised thereby that the means for bringing about the said movement are conventional hydraulic means.

11. A tool, as claimed in claim 6, characterised thereby that the auger is of the split type, the bucket comprising two or more parts which are so connected that they can be moved apart and thus exert pressure on the wall of the bore shaft consolidating the latter and preventing a cave in.

1 2. A tool, as claimed in any one of claimes 5 to 11 characterised thereby that it is enclosed by a number of - at least two curved plates.

1 3 A tool, as claimed in claim 7, characterised by being provided with plane plates at the opposite, flat sides of the grab.

14. A tool claimed in claim 6 or claim 11, characterised thareby that the said curved plates are connected with the auger itself by a number of tension springs.

1 5. A tool as claimed in claim 6, characterised thereby that it carries ring shaped members which are slipped on the auger and which rings comprise at least two parts and are pressed by the crosswise expansion of the auger onto the wall of the bore hole to form a ling thereof.

16. A tool according to any one of claims 1 to 6 in association with a device for use therewith, said device being constituted by at least two inter-connected plates enclosing a space between them in which space are positioned means for moving the plates apart, such means being actuated hydraulically or pneumatically or mechanically.

17. The device claimed in claim 16, characterised thereby that it comprises a number of slightly curved plates which together define a cylindrical body within which a number of piston-in-cylinder means are positioned for moving the plates apart from one another.

18. The device claimed in claim 16, characterised thereby that it is constituted by at least two plane plates which are positioned at a distance from one another, the said pistonin-cylinder means being accommodated within the space between the plates.

19. The device claimed in claims 14 and 17, characterised by the provision of four piston-in-cylinder tool, positioned as a cross shaped structure, the cylinders being held on a bar extending co-centrically within the device, the piston rods being connected with the curved plates forming the device.

20. The device claimed in claim 19, characterised thereby that it is positioned on top of an auger of bucket type.

21. The device claimed in claims 16 and 1 7, characterised thereby that the plane plates are inter-connected by a telescoping connection, piston-in-cylinder tools being positioned flanking the said telescoping connection.

22. Soil drilling tools, substantially as hereinbefore described and shown in the accompanying drawings.

23. A method according to claim 1 of drilling bore holes substantially as hereinbefore described and illustrated by reference to the accompanying drawings.