US 3887021 A
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O Umted States Patent 1 1 1 3,887,02 l Elbert 1 June 3, 1975  METHOD AND APPARATUS FOR BORING 2,672,122 :anney 2,78 ,8 1 ayes 17 X DRAIN HOLES IN GROUND 2,805,043 9/1957 Williams 175/422 X  to Ketil Elbert. 631 ot 3,386,521 6/l968 Chadderdon 175/422 Antoine Rd., Westmount, Quebec, Canada Primary Examiner-Frank L. Abbott 22 l d; F 4 1974 Assistant ExaminerRichard E. Favreau  Appl. No.: 439,142  ABSTRACT A method and a device for boring holes in which the  US. Cl- 175/422; 61/11; 175/67 boring device comprises a rigid hollow tubular y  1.1L C1. E211) 7/18. having a nozzle at an end thereof and connected at the Fleld of 86311311 1, 63, 35, other end to a hose which pp water under p 175/422, 213, 171, 21 sure. The nozzle is provided with forwardly and rearwardly directed jet orifices which drive the boring de-  References C'ted vice into the ground to bore a hole therein. The device UNITE STATES PATENTS is also provided with means to releasably engage an 666,799 l/190l Buckwalter 175/422 end of a drain element which is positioned into the 1,409,140 3/1922 Bignell 175/422 X hole and left therein after it has been bored down to 21 1,766,487 6/1930 Conner 175/422 drain bed 1,831,209 11/1931 Thomley et al. 175/422 X 2,660,250 11 /1953 Gage et al 175/422 x 6 Claims, 3 Drawmg Figures PATENTEUJUH 3 ms 3881.021 SHEET 1 29 FIG. 1
METHOD AND APPARATUS FOR BORING DRAIN HOLES IN GROUND BACKGROUND OF INVENTION 1. Field of the Invention This invention relates to a method and a device for boring holes and more particularly, but not exclusively, for boring holes in soft ground, such as clay, to provide drain holes in such type ground. The invention also relates to placing drainage means in such holes in order to provide a proper drainage path along the hole.
2. Description of Prior Art It is well known that soft land formations, which result from an accumulation of water with clay or the like material, causes very serious problems. For example, landslides which are currently happening in populated areas is just an example. It is also well known that clay or similar type earth materials which are not easily permeable to water would become firm and constitute a good base for constructions if they could be maintained dry.
SUMMARY OF INVENTION According to the presently available method, drains are placed in land formations by making spaced-apart holes and placing either subsequently or at the same time an elongated flexible drain which could be a corrugated plastic body surrounded by an impregnated absorbent paper. One limitation of existing methods is the depth to which the drains can be placed, with the result that if the lower extremity of the drain is not far enough into the ground, drainage will simply be insufficient and unsatisfactory. A further limitation in existing methods, especially when working on soil which is susceptible to landslides, is the limit of the weight of the equipment which can be tolerated on the surface.
There is thus a need for the provision of the placement of drains sufficiently deep in ground that once drainage is in operation the ground will be firm and solid, it will not be susceptible to landslides and it will therefore be possible to use this portion of land for construction purposes or the like.
In accordance with the present invention, there is provided a method and an apparatus by means ofwhich it is possible to insert drains to relatively unlimited depths of at least, for example, 100 to 175 feet.
According to a broad aspect, the present invention relates to a method of making drain holes in ground and which comprises boring a hole in the soil by means of water jets directed under pressure forwardly and rearwardly from a boring device. A drainage bed is detected by means of the water which is introduced in the hole by the boring device. A drain element is also inserted in the hole by the boring device and released therein before retracting the boring device.
According to a further broad aspect, the present invention provides a boring device comprising a rigid hollow tubular body having a nozzle at an end thereof and connectable means at an opposite end for securement to a water delivery means. The nozzle has a forwardly directed jet orifice and at least two retro-directed orifices. Means are further provided for releasably engaging an end of a drain element to be positioned in a hole bored by the device.
It would appear to be advantageous to form the water jet by supplying water under a high pressure, for example, of 4,000 to 5,000 psi to a nozzle.
In other words, the method according to the invention is accomplished by forming a hole by water jetting at extremely high pressure using a nozzle, and optionally using the jetting nozzle as a means of pulling the drain down the hole.
Depending on the type of soil in which the drainage operation is carried out, the drain may be inserted during the initial passage of the jetting nozzle or the hole may first be formed to the desired depth and then the drain will be inserted by again passing the jetting nozzle down the hole, at a lower pressure. When the hole is formed first, and the drain is introduced later, the lower pressure will for example vary from 1,000 to about 4,000 psi, preferably about 2,000 psi.
When the drain is introduced at the same time as the hole is being made, as for example in clay formations which are not solid enough to maintain the hole side walls for any length of time, the pressure will be extremely high, for example, from 4,000 to 5,000 psi. If the conditions of the ground permit, it is of course preferable to insert the drain at the same time as the hole is being drilled, because this will require only one operation instead of two.
After having reached a drainage bed, for example, a sand bed, and having inserted the drain into the hole, which will be indicated by a sudden disappearance of water in the drilled hole or sand coming to the surface of the hole, the nozzle will be retrieved, while making sure that the drain remains in place at the bottom of the hole in contact with the drainage bed. While practicing this method, care should be taken to balance the various water jets, if more than one is used, in order to make sure that the drilled hole extends in the desired direction in the ground without too many small deviatlons.
BRIEF DESCRIPTION OF DRAWINGS In the drawings which illustrate the invention,
FIG. 1 is a perspective view of the apparatus utilized to form the drain holes;
FIG. 2 is a fragmented sectional view of the boring device, and
FIG. 3 is a view of a drain end adaptor.
DESCRIPTION OF PREFERRED EMBODIMENTS Referring to the drawings, the boring device 10 according to the invention comprises an elongated hollow cylindrical body 11 which is provided with connectable threaded ends 13 and 15. The end 13 connects the device body 11 to a hose 17 which will be used to deliver water under high pressure (see FIG. 3) to the device 10. The end 5 connects the body 11 to a nozzle 19 which will now be described. The nozzle 19 has a semiovoidal longitudinal section, it being understood that its cross-section is circular. Coinciding with the longitudinal axis of the nozzle 19 there is a front orifice 21 which is in communication with the hose 17 to deliver water under extremely high pressure. The nozzle 19 also comprises peripheral converging conical portions I3, 15 which are slanted towards one another to form a junction 18. Opening in the slanted conical portion 13 there are five back orifices 14 which are formed at an angle of with respect to the conical face 13. However, this angle can vary appreciably depending on circumstances. Consequently, the orifice 21 will constitute the forward jet of the nozzle 19 and the five orifices 14 will define the retro jets of the nozzle.
A hook 22 is secured to the outer wall of the body 11 and serves to carry the drain (not shown in detail) as the nozzle 19 penetrates into the ground. In order to protect the hook 22, as well as the drain, from surrounding material and to help in the unhooking of the drain when the nozzle 19 has reached the drainage bed and when it is desired to pull out the nozzle 19 from the hole 37, there is provided a V-shaped guard plate 23 which is formed from a narrow strip of metal. Referring to FIG. 2 of the drawings, it will be seen that the guard plate is very long and defines a shallow V configuration to provide two sloping walls.
The operation of the boring device will now be de scribed with particular reference to FIG. 3 of the drawings. The device body 1 l is connected to the water hose 17 and a nozzle 19 is fitted to the front end 15. The end of the drain 31 is secured in a drain end adaptor plate 25 by riveting or other suitable means and the nozzle is thereafter oriented in a vertical direction towards the surface of the ground. A securement hole 26 is provided in the tapered forward end 24 for attachment to the hook 22. The plate 25 is constructed of metal or other suitable material.
The water pump 27 which is mounted on a movable platform or vehicle 29 provides water to the device at a pressure of between 4,000 and 5,000 psi and with a water volume of 56 U.S. gallons per minute. As the water exits from the nozzle 19, it breaks the soil particles and the front nozzle will penetrate into the ground by the force created by the retro jets 14 which also enlarge the hole 37. The boring device 10 also carries with it the drain 31 which unrolls from a cylinder 33 mounted at a convenient location. Preferably, the drain is very close to the hole 37 whereby it can extend vertically therein not to be damaged by the edge of the hole 37. For example, the drain can be secured to the vehicle 29 with the hose l7 and drain 31 extending vertically downward into the hole 37. As the nozzle bores the hole and entrains the drain 31, water accumulates in the hole and ejects the sludge through the hole opening until the nozzle hits a drainage bed. When a drain age bed is attained the sand particle of the bed may rise to the surface through the hole or the volume of water coming out of the hole may diminish indicating that sub-soil drainage is taking place.
The boring device 10 is retracted from the hole, and the latter may be filled with sand or will collapse with itself depending on the soil hardness and the size of the hole in a specific time period. The retraction is accomplished by reversing the rotational drive of the cylinder 35, the latter now operating as a hydraulic retrieval device. As soon as the boring device 10 starts its ascending motion in the hole 37, the drain is being unhooked from the hook 21 and it therefore remains in contact with the drainage bed at the bottom of the hole. This is made possible because of the particular shape of the hook 21 and the presence of the guard 23. As shown in FIG. 2, the hook 22 has an opening 34 which extends angularly outward and downward of the body 11. The guard plate 23 protects this opening, as the hole is being bored, and also guides the end 24 of the adaptor 25 during retraction.
lt will be realized that this system can operate with relatively light equipment located either remote or at the site of the hole so that when the ground is very soft, there is no excessively heavy weight bearing on the soil. The equipment may also be located remotely from the hole and only the device, hose and drain brought at the immediate site of the hole to be dug.
An advantage of the Applicants method is that there is an automatic sensor which tells the operator when the boring device has reached a drain bed, that is, the sand or the drainage bed is now in contact with the drain.
The drain element, per se, is a commercially available article and consists of a flat paper filter jacket covering a corrugated plastic core which forms elongated drain channels within the jacket and throughout the length of the drain. Of course, other type of flexible drains, such as tubes, etc., may be positioned in the hole by the boring device.
From tests conducted in the field, it was found that with a boring device for boring holes of approximately 6 to 10 inches in soft clay and operating at from 4,000 to 5,000 psi, that the device would progress at approximately 20 feet per minute down to about at least l00 feet with no obstructions being encountered.
1. A boring device for boring a hole in soft ground, such as clay or the like, and for insertion of a drain element in said hole, said device comprising a rigid hollow tubular body having a nozzle at an end thereof and connectable means at an opposite end for securement to water delivery means, said nozzle having a forwardly directed jet orifice and at least two retro-directed orifices for causing penetration of said body into said ground, and hook means secured to an outer wall of said tubular body for releasably engaging an end of said drain element to be positioned in a hole bored by said device.
2. A boring device as claimed in claim 1 wherein said nozzle is removably secured to the end of said tubular body whereby to provide nozzles having different size or location of said orifices.
3. A boring device as claimed in .claim 1 wherein said water delivery means is a hose connected to a water pump capable of delivering water to said hollow body at a pressure of from 4,000 to 5,000 psi and at a rate of 56 U.S. gallons per minute.
4. A boring device as claimed in claim 1 wherein said hook means for releasably engaging an end of a drain is a hook secured to said tubular body and having a hook opening facing in the direction of said nozzle.
5. A boring device as claimed in claim 4 wherein there is further provided a guard plate secured to said body and positioned in front of said hook opening and defining a sloping wall extending outwardly from said hook opening sufficiently to protect said hook from a bore sidewall.
6. A boring device as claimed in claim 5 wherein said hook opening extends angularly outward whereby to facilitate disengagement with a drain end adaptor plate secured to said end of said drain which is secured to said hook.