Patent Application
20050265790
This invention relates to a ground anchor, for use underground in mine shafts, tunnels and the like, or particularly, for tying down structures, such as towers, electricity pylons and the like with guy wires above ground, and, more particularly, to an assembly of said anchor comprising a portion thereof encased in an explosive-loaded housing.
Utilities and other companies, which use guy towers, use various mechanical devices to anchor the guy wires that hold the towers vertically. Typical installations require than an anchor rod or shaft held in the ground to provide a holding power sufficient to hold the tower upright under the designed conditions of wind, ice and tower vibrations.
Typical examples of such mechanical anchors known in the art include multi-helix screws, expanding anchors, grouted anchors and wood mats.
Below ground or within mountains and the like, as in mine shafts, tunnels and the like, retained members such as rods, bolts, thick wire members, and the like, may be retained in the walls, face, roof or floor of a tunnel within a concrete-filled borehole.
Although the aforesaid prior art is in established use, there is, however, a need for a ground anchor system that provides less disturbance of the ground adjacent the resultant borehole during installation and completion of the installed resultant ground anchor.
It is an object of the present invention to provide a ground anchor assembly which provides a resultant installed ground anchor that minimizes disruption of the annular sides of the borehole and maintains the integrity of the surrounding ground.
Accordingly, in its broadest aspect, the invention provides a ground anchor retaining means assembly for providing a ground-retained anchor retaining means to restrain an object connected thereto, said assembly adapted to be received within a borehole within said ground and comprising
The invention provides in one preferred aspect, a ground anchor assembly of use in providing a ground-retained anchor for use with guy means to restrain a vertical structure, said assembly adapted to be received within a borehole within said ground and comprising
By the term deformation of the housing in this specification and claims is meant that the sides of the housing are deformed in whole or in part, with or without partial break-up or fragmentation of the sides into a plurality of finger or claw like portions, as to provide frictional abutment with or are embedded within the ground constituting the sides of the borehole.
The present invention provides an explosive anchor assembly that uses the energy generated by a small charge of explosive located inside a metal housing to expand or burst the housing to create a friction anchor between the metal and the ground or earth material. The metal expands in whole or in part until an intimate contact between the ground or earth material and the metal is achieved.
The anchor assembly as hereinabove defined may be used in above and below ground situations, e.g. for tying down structures, such as towers, buildings or the like, as well as in mine shafts, tunnels below ground or within mountains as providing shaft, rod or thick wire members retained in the walls, face, roof or floor of a tunnel.
In one aspect, the invention provides an assembly as hereinabove defined wherein the effective amount of the explosive is sufficient to effect deformation of the housing intermittent of the length of the housing at intermittent portions of the housing to effect penetration of the intermittent housing portions into the ground as to be in frictional engagement with the ground.
In another aspect of the invention the effective amount of the explosive is sufficient to effect deformation of the housing along the length of the housing without disintegration thereof to effect frictional abutment of the deformed housing with the ground.
In a further aspect, the effective amount of the explosive is sufficient to effect partial disintegration of the housing as to produce a plurality of housing protrusions penetrated within the ground.
The housing protrusions may penetrate the ground or earth material thickness around the borehole to a desired thickness as determined by the skilled person dependent, inter alia, for example, on the strata and nature of the ground. A typical thickness is selected from 3-15 cm.
In a further aspect, the invention provides a system comprising an object restrained by an object anchor means to or within the ground comprising:
In preferred embodiments, the housing is connected to the anchor by complimentary threaded means, such as by nuts and bolts.
The ground entering terminal portion of the elongate anchor is preferably tapered to facilitate ease of entry.
In alternative embodiments, the explosive-loaded assembly may be disposed within a pre-drilled borehole.
In a yet further aspect, the invention provides a method of constructing a system comprising an object restrained to the ground with restraining anchor means comprising an elongate anchor disposed within the ground and attachment means attaching the anchor to the object; the method comprising the steps of locating the anchor within a borehole in the ground and attaching the anchor to the object;
In order that the invention may be better understood, preferred embodiments will now be described by way of example only, with reference to the accompanying drawings, wherein.
With reference to
In more detail, housing 14 at its lower terminal portion 22 is tapered and also defines an inner threaded nut portion 24 to receive a complimentary threaded bolt portion 26 of rod 12 which protrudes through nut portion 24 as to facilitate entry into the bottom 28 of borehole 18, if desired.
An upper portion 30 of rod 12 is in suitable close fitting engagement with the neck portion 32 of housing 14. Thus, housing 14 and rod 12 define therebetween a chamber 34 within which is containing a desired type and amount of explosive which is preferably located intermittent of the vertical length of housing 14 and rod 12, as desired, as hereafter further explained.
Anchor rod 12 is of sufficient length to extend beyond the borehole, if desired, and has retaining shackle means 35 by which the anchor holds a guy wire 36 which ties down the tower structure 38 to be held down.
The dimensions of the rod 12, housing 14, amount and type of explosive 16, borehold 18 size are readily selected dependent on the nature of the ground, earth, strata and the like and the holding power required.
The explosive 16 may be located the full length of housing 14 or intermittent therein as shown in the embodiment of
With reference to
The aforesaid embodiments have been described with reference to the anchor assembly being placed in a vertical borehole. However, it will be understood that the assembly may be placed at an angle with respect to the ground, as is known in the art.
Fragments 72 may be desirably operably produced to penetrate to a depth of, typically 5-8 cm, 15 cm or greater by judicious selection of housing dimensions and amount and type of explosive, disposition with respect to the nature of the ground.
As known in the prior art, anchor rods/shafts may be provided in modular form suitably adapted to be joined one shaft to another in 1m, 2m or 3m sections to give a desired total suitable length for use within the borehole. Thus, several assemblies according to the present invention, may be extended into a single joined shaft having suitably located explosive-loaded housings intermittent or full length of the assembled shaft within the ground.
The assemblies according to the invention may be selectively used in all types of ground, such as, for example, limestone strata, granite, Canadian Shield strata, soft soils, sands and permafrost.
A major intention of the practise of the invention defined herein is to try and maintain the integrity of the ground surrounding the borehole and to not disrupt the majority of the annular sides around the resultant positioned anchor, with the minimum of breakaway of the sides of the ground.
Although this disclosure has described and illustrated certain preferred embodiments of the invention, it is to be understood that the invention is not restricted to those particular embodiments. Rather, the invention includes all embodiments which are functional or mechanical equivalence of the specific embodiments and features that have been described and illustrated.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2,468,359 | May 2004 | CA | national |
