GB2233056A - Rock bolt for mine roofs - Google Patents
Rock bolt for mine roofs Download PDFInfo
- Publication number
- GB2233056A GB2233056A GB8912015A GB8912015A GB2233056A GB 2233056 A GB2233056 A GB 2233056A GB 8912015 A GB8912015 A GB 8912015A GB 8912015 A GB8912015 A GB 8912015A GB 2233056 A GB2233056 A GB 2233056A
- Authority
- GB
- United Kingdom
- Prior art keywords
- bolt
- bore
- roof
- roof bolt
- duct
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 239000011435 rock Substances 0.000 title claims abstract description 19
- 239000000203 mixture Substances 0.000 claims abstract description 13
- 238000005553 drilling Methods 0.000 claims abstract description 6
- 238000002347 injection Methods 0.000 claims abstract description 6
- 239000007924 injection Substances 0.000 claims abstract description 6
- 238000005086 pumping Methods 0.000 claims abstract description 4
- 238000000034 method Methods 0.000 claims description 13
- 230000008878 coupling Effects 0.000 claims 1
- 238000010168 coupling process Methods 0.000 claims 1
- 238000005859 coupling reaction Methods 0.000 claims 1
- 239000011347 resin Substances 0.000 description 16
- 229920005989 resin Polymers 0.000 description 16
- 239000003795 chemical substances by application Substances 0.000 description 8
- 239000002775 capsule Substances 0.000 description 2
- 239000004848 polyfunctional curative Substances 0.000 description 2
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D20/00—Setting anchoring-bolts
- E21D20/02—Setting anchoring-bolts with provisions for grouting
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D20/00—Setting anchoring-bolts
- E21D20/02—Setting anchoring-bolts with provisions for grouting
- E21D20/028—Devices or accesories for injecting a grouting liquid in a bore-hole
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D21/00—Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection
- E21D21/0026—Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection characterised by constructional features of the bolts
- E21D21/0053—Anchoring-bolts in the form of lost drilling rods
Landscapes
- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Structural Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Piles And Underground Anchors (AREA)
- Joining Of Building Structures In Genera (AREA)
Abstract
A roof bolt is installed in a mine by drilling a bore 10 into the rock strata 12, inserting a roof bolt 32 into the bore, and then pumping a setting or curable composition through a duct which extends from end-to-end within the bolt. The composition thus flows out of the inner end of the bolt and into the bore, then flows back over the outside of the bolt to the outer end of the bore. The roof bolt may be formed as a drill bit which is used to drill the bore. The composition is supplied to the duct via a screw connector 36 by means of an injection pump 30 and hose 34. <IMAGE>
Description
ROOF BOLTING
This invention relates to a roof bolt for use in mining and to a method of installing a roof bolt.
It has been common practice to install a roof bolt by drilling a bore through the roof strata, insert separate capsules of resin and hardening agent into the bore, then insert the roof bolt and twist the latter to produce a mixing action on the resin and hardening agent, after which the mixed resin and hardener are left to set. Then a support plate can be clamped against the rock formation by tightening a nut onto the threaded end of the bolt left projecting from the drilled bore. However it is not possible to ensure that the resin hardening agent have been properly mixed together.
Recently it has been proposed to use a pump which pumps and mixes resin and hardener into the bore around a bolt once the bolt has been inserted into the bore.
However this technique does not necessarily ensure that the mixed composition will reach to the inner end of the bore.
We have now devised a roof bolt and a method of installing this roof bolt which overcomes these difficulties with the known practices.
In accordance with this invention, there is provided a method of installing a roof bolt, which comprises drilling a bore into rock strata and inserting a roof bolt into the bore, which roof bolt is formed with a duct from end to end, and pumping a setting or curable composition into the bolt duct at the outer end of the bolt so that this composition flows out of the duct at the other end of the bolt and into the rock bore.
In carrying out this method, the composition (e.g. mixed resin and hardening agent) is introduced through the bolt duct and into the rock bore at its inner end. The composition then flows along the bore, over outside of the bolt, towards the outer end of the bore. It is therefore ensured that the composition will be introduced into the inner end of the rock bore and if it is seen to reach the open end of the rock bore, it will have filled the rock bore all along its length.
Also in accordance with this invention, there is provided a roof bolt formed with a longitudinal duct from endto-end.
Preferably the roof bolt has one end which is externally screw-threaded to receive a nut for tightening in position a support plate which is placed over this end of the bolt and against the rock strata. Preferably a hose from an injection pump can be coupled to this end of the bolt using a connector piece which is screwed onto the bolt using its external screw-threading.
The roof bolt may be formed as a drill bit which is used to drill the bore into the rock strata, and then the drilling machine is detached and the drill bit is left in the bore to act as the roof bolt as described above.
An embodiment of this invention will now be described by way of example only and with reference to the accompanying drawings, in which:
FIGURE 1 is a diagrammatic section through rock strata forming the roof and an underground mine and showing a prior art roof bolt and technique of installing it;
FIGURE 2 is a similar view showing a recent proposal for installing a roof bolt; and
FIGURE 3 is a similar view showing a roof bolt in accordance with this invention and its method of installation.
Referring to Figure 1; the common practice hitherto has been to drill a bore 10 into the rock strata 12 forming the roof of the underground mine, then to insert different capsules 14, 16 of resin and hardening agent, then insert the roof bolt 18 and twist this to and fro to mix the resin and hardening agent. The resin is then left to harden and then an apertured support plate 20 is placed over the projecting end of the bolt 18 and against the rock, a nut 22 being tightened onto the screw threaded end of the bolt to clamp the support plate against the roof.
Referring to Figure 2, recently it has been proposed to use an injection pump 30 to pump and mix resin and hardening agent into the bore 10 around the bolt 18 once this has been inserted into the bore. Again, once the pumping has been completed and the resin has been allowed to set, the support plate 20 is clamped against the roof using the nut 22.
In accordance with this invention and referring to Figure 3, a steel bolt 32 is used which has a longitudinal duct extending from end-to-end along its axis. The bolt 32 is inserted into the drilled bore 10. Then the hose 34 from the injection pump 30 is coupled to the projecting end of the bolt 32, using a connector piece 36 which screws onto the screwthreaded end of the bolt. The pump is then used to pump and mix resin and hardening agent in the required proportions through the duct in the roof bolt and into the inner end of the drilled bore 10. The resin flows back along the bore over the outside of the bolt towards the open end of the bore and into any spaces 38 between the rock strata.
The method described with reference to Figure 3 ensures that the resin is introduced into and will fill the inner end of the drilled bore and further and if it is seen to reach the open end of the bore, it will be known to have filled the bore all along its length.
The pump hose is disconnected from the bolt 18 and the resin is allowed to set. Then the apertured support plate is placed over the projecting end of the bolt and against the rock strata and a nut is tightened onto the screw threaded end of the bolt to clamp the support against the mine roof, in the usual manner.
Also in accordance with this invention, the roof bolt may be formed as a drill bit which is used to drill the bore. Then the drilling machine is detached from the drill bit, which is left in the bore and coupled to the injection pump for injecting resin, as described above.
Claims (8)
1) A method of installing a roof bolt, which comprises drilling a bore into rock strata and inserting a roof bolt into the bore, which roof bolt is formed with a duct from end to end, and pumping a setting or curable composition into the bolt duct at the outer end of the bolt so that this composition flows out of the duct at the other end of the bolt and into the rock bore.
2) A method as claimed in claim 1, in which the roof bolt has one end formed with a coupling which in use is connected to a hose from an injection pump.
3) A method as claimed in claim 1 or 2, in which the roof bolt is formed as a drill bit and is used to drill the bore into the rock strata.
4) A method of installing a roof bolt, the method being as claimed in claim 1 and substantially as herein described with reference to Figure 3 of the accompanying drawings.
5) A roof bolt which is formed with a longitudinal duct from end-to-end thereof.
6) A roof bolt as claimed in claim 5, which has one end externally screw-threaded.
7) A roof bolt as claimed in claim 5 or 6, which is formed as a drill bit.
8) A roof bolt substantially as herein described with reference to Figure 3 of the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8912015A GB2233056A (en) | 1989-05-25 | 1989-05-25 | Rock bolt for mine roofs |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8912015A GB2233056A (en) | 1989-05-25 | 1989-05-25 | Rock bolt for mine roofs |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8912015D0 GB8912015D0 (en) | 1989-07-12 |
| GB2233056A true GB2233056A (en) | 1991-01-02 |
Family
ID=10657317
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8912015A Withdrawn GB2233056A (en) | 1989-05-25 | 1989-05-25 | Rock bolt for mine roofs |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2233056A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117513301B (en) * | 2024-01-04 | 2024-04-05 | 北京建筑大学 | Composite anchor rod structure for soft soil foundation treatment |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1007392A (en) * | 1962-07-05 | 1965-10-13 | Chester Irving Williams | Groutable rock bolt assembly |
| GB1018689A (en) * | 1964-11-04 | 1966-02-02 | Chester Irving Williams | Method of grouting a hollow rock bolt and rock bolt assembly |
| GB1131954A (en) * | 1966-02-28 | 1968-10-30 | James Deans Cumming | Rock bolt assembly |
| GB1323033A (en) * | 1970-02-03 | 1973-07-11 | Williams C I | Rock bolt assembly |
| US4055051A (en) * | 1976-01-08 | 1977-10-25 | The United States Of America As Represented By The Secretary Of The Interior | Unitary drill bit and roof bolt |
| GB2095308A (en) * | 1981-03-24 | 1982-09-29 | Willich F Gmbh & Co | Method and apparatus for consolidating rock strata |
| US4395859A (en) * | 1980-06-05 | 1983-08-02 | State Of Illinois, Department Of Transportation | Method and apparatus for securing an object to a support structure |
| GB2169050A (en) * | 1984-12-15 | 1986-07-02 | Dowty Group Services | Anchor bolt and method of application thereof to associated structure |
| US4650373A (en) * | 1985-11-14 | 1987-03-17 | Seegmiller Ben L | Rock bolt construction and installation |
| EP0259755A1 (en) * | 1986-09-10 | 1988-03-16 | Gd-Anker Gmbh | Rock anchoring bolt |
| GB2206172A (en) * | 1987-06-25 | 1988-12-29 | Coal Ind | Rock bolts |
-
1989
- 1989-05-25 GB GB8912015A patent/GB2233056A/en not_active Withdrawn
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1007392A (en) * | 1962-07-05 | 1965-10-13 | Chester Irving Williams | Groutable rock bolt assembly |
| GB1018689A (en) * | 1964-11-04 | 1966-02-02 | Chester Irving Williams | Method of grouting a hollow rock bolt and rock bolt assembly |
| GB1131954A (en) * | 1966-02-28 | 1968-10-30 | James Deans Cumming | Rock bolt assembly |
| GB1323033A (en) * | 1970-02-03 | 1973-07-11 | Williams C I | Rock bolt assembly |
| US4055051A (en) * | 1976-01-08 | 1977-10-25 | The United States Of America As Represented By The Secretary Of The Interior | Unitary drill bit and roof bolt |
| US4395859A (en) * | 1980-06-05 | 1983-08-02 | State Of Illinois, Department Of Transportation | Method and apparatus for securing an object to a support structure |
| GB2095308A (en) * | 1981-03-24 | 1982-09-29 | Willich F Gmbh & Co | Method and apparatus for consolidating rock strata |
| GB2169050A (en) * | 1984-12-15 | 1986-07-02 | Dowty Group Services | Anchor bolt and method of application thereof to associated structure |
| US4650373A (en) * | 1985-11-14 | 1987-03-17 | Seegmiller Ben L | Rock bolt construction and installation |
| EP0259755A1 (en) * | 1986-09-10 | 1988-03-16 | Gd-Anker Gmbh | Rock anchoring bolt |
| GB2206172A (en) * | 1987-06-25 | 1988-12-29 | Coal Ind | Rock bolts |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8912015D0 (en) | 1989-07-12 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |