AU770287B2 - Tube-formed rock bolt - Google Patents
Tube-formed rock bolt Download PDFInfo
- Publication number
- AU770287B2 AU770287B2 AU28400/00A AU2840000A AU770287B2 AU 770287 B2 AU770287 B2 AU 770287B2 AU 28400/00 A AU28400/00 A AU 28400/00A AU 2840000 A AU2840000 A AU 2840000A AU 770287 B2 AU770287 B2 AU 770287B2
- Authority
- AU
- Australia
- Prior art keywords
- tube
- rock bolt
- bolt according
- formed rock
- bore hole
- 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.)
- Ceased
Links
- 239000011435 rock Substances 0.000 title claims description 21
- 239000000463 material Substances 0.000 claims description 6
- 230000002093 peripheral effect Effects 0.000 claims description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 2
- 229910052782 aluminium Inorganic materials 0.000 claims description 2
- 239000004411 aluminium Substances 0.000 claims description 2
- 238000001125 extrusion Methods 0.000 claims description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- TVEXGJYMHHTVKP-UHFFFAOYSA-N 6-oxabicyclo[3.2.1]oct-3-en-7-one Chemical compound C1C2C(=O)OC1C=CC2 TVEXGJYMHHTVKP-UHFFFAOYSA-N 0.000 description 1
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000012530 fluid Substances 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
- 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
- E21D21/004—Bolts held in the borehole by friction all along their length, without additional fixing means
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)
- Dowels (AREA)
- Forging (AREA)
- Extrusion Of Metal (AREA)
- Rigid Pipes And Flexible Pipes (AREA)
Description
TUBE-FORMED ROCK BOLT The present invention relates to a tube-formed rock bolt with closed profile, which is inserted in a bore hole and then expanded into contact with the wall of the bore hole through plastic deformation by means of internal pressurization.
In a previously known rock bolt, see e.g. US-A-4 509 889, a comparatively thinwalled tube of mild steel is used, which during manufacture is deformed such that its peripheral length is larger than the circumference of the bore hole. A drawback with this formation is that the tube is relatively thin-walled in order to allow deformation against the wall of the bore hole. This gives a comparatively small cross-sectional area, which restricts the tensile strength of the rock bolt. The unsymmetrical form of the rock bolt gives as result that the contact force against the rock varies along the periphery, which limits the load carrying capacity. A further drawback is that the steel material is exerted to corrosion attack.
The present invention provides a tube-formed rock bolt including an elongated tube which in a cross section has a peripheral length which exceeds a circumference of a circle having a diameter being equal to the largest transverse dimension of said tube, two end closures on said tube and a passage at one of said end closures for pressurization of an internal space defined by said tube for expansion of said tube against a bore hole, c h a r a c t e r i z e d thereby that said tube has a varying material thickness in a peripheral direction.
The present invention, which is defined in the subsequent claims, aims at S achieving a tube-formed rock bolt having a substantially higher tensile strength. This is achieved primarily because the rock bolt comprises a tube, which has a material thickness varying along the periphery. Through this one can increase the crosssectional area of the tube substantially at the same time as one has parts, which are easily deformed so that the rock bolt gets a secure grip against the wall of the bore hole.
The advantageous embodiments of the invention given in the subclaims give as results that the rock bolt obtains good corrosion resistance, is easy to manufacture and gives a good contact force against the wall of the bore hole around the hole.
la Two embodiments of the invention are described below with reference to the accompanying drawings in which fig 1 shows a tube-formed rock bolt in perspective with one end closure removed in order to show the cross-sectional form. Fig 2 shows a cross section through the bolt according to fig 1 and schematically the surrounding bore hole in which the rock bolt is to be anchored. Fig 3 shows an alternative embodiment of the invention.
e go go WO 00/75489 PCT/SE00/00229 2 The tube-formed rock bolt shown in the drawings comprises an elongated tube 1 provided with two end closures 2,3. In the shown example the end closures are made as caps, which sealingly have been connected with the tube 1. Through this a room 5 is created between the tube 1 and the end closures 2,3. This room can be pressurised via a passage 4 at the end closure 2. The end closures can be achieved in other ways. The essential is that the ends of the tube 1 are sealed so that one through pressurisation of the room 5 can expand the tube 1 to contact against the bore hole 11. The tube 1 is, for instance, made by means of extrusion of an aluminium-based material, e.g. EN-AW 6082-T4. The tube 1 can thereby advantageously be given cross-sectional forms like those shown in figs 2 and 3. By making the profile symmetrical relative to the longitudinal sections 6,7 one obtains a relatively even distribution of the contact force between the tube 1 and the bore hole 11 after expansion of the bolt. One obtains about the same result with the bolt form shown in fig 3.
This means that the bolt can be loaded more heavily without gliding in the bore hole. The bolt shown in fig 2 comprises four substantially triangularly formed parts 8, which have large cross-sectional areas and thus large stiffness and tensile strength. These parts are connected by means of U-shaped deformation parts 9. In order to increase the flexibility the tube profile has been provided with a number of circularly formed parts 12 at the deformation parts 9.
When a rock bolt is to be anchored in a bore hole the bolt is pushed into the bore hole with the end closure 3 at the inner end of the bore hole. Then pressure fluid is supplied via the passage 4 to the room 5 surrounded by the tube 1. Through this the tube 1 is expanded so that it contacts the wall of the bore hole 11 hardly. Then the room 5 is unloaded whereby the tube 1 remains firmly anchored, since the previous expansion has deformed the tube 1 plastically.
The invention can, of course, be varied within the scope of claim 1. The profile can, for instance, have more or fewer than four stiff parts. An example of this is shown in fig 3.
Claims (4)
1. Tube-formed rock bolt including an elongated tube which in cross section has a peripheral length which exceeds a circumference of a circle having a diameter being equal to the largest transverse dimension of said tube, two end closures on said tube and a passage at one of said end closures for pressurization of an internal space defined by said tube for expansion of said tube against a bore hole, c h a r a c t e r i z e d thereby that said tube has a varying material thickness in a peripheral direction.
2. Tube-formed rock bolt according to claim 1, c h a r a c t e r i z e d thereby that said tube is manufactured by means of extrusion.
3. Tube-formed rock bolt according to claim 1 or 2, c h a r a c t e i z e d thereby that said tube includes an aluminium-based material.
4. Tube-formed rock bolt according to any one of claims 1-3, c h a r a c t e r i z e d thereby that said tube is symmetrical about two longitudinal sections which are perpendicular relative to each other. Tube-formed rock bolt according to any one of claims 1-3, c h a r a c t e r i z e d thereby that said tube includes a number of substantially 0' triangularly formed stiff parts and intermediate U-shaped deformation parts. eg0 0 20 DATED this 8 th day of December 2003 e 0. ALTAS COPCO ROCK DRILLS AB WATERMARK PATENT AND TRADE MARK ATTORNEYS LEVEL 21, "ALLENDALE SQUARE TOWER" 00 25 77 ST GEORGES TERRACE PERTH WA 6000 AUSTRALIA S.P20523AU00
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE9902065A SE512834C2 (en) | 1999-06-04 | 1999-06-04 | Tubular mounting bolt |
| SE9902065 | 1999-06-04 | ||
| PCT/SE2000/000229 WO2000075489A1 (en) | 1999-06-04 | 2000-02-07 | Tube-formed rock bolt |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU2840000A AU2840000A (en) | 2000-12-28 |
| AU770287B2 true AU770287B2 (en) | 2004-02-19 |
Family
ID=20415894
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU28400/00A Ceased AU770287B2 (en) | 1999-06-04 | 2000-02-07 | Tube-formed rock bolt |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP1183441A1 (en) |
| JP (1) | JP2003501573A (en) |
| AU (1) | AU770287B2 (en) |
| CA (1) | CA2371136A1 (en) |
| SE (1) | SE512834C2 (en) |
| WO (1) | WO2000075489A1 (en) |
| ZA (1) | ZA200109337B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT412739B (en) * | 2002-01-22 | 2005-06-27 | Techmo Entw & Vertriebs Gmbh | METHOD AND DEVICE FOR DRILLING A HOLE IN GROUND OR ROCK MATERIAL AND FOR FORMING AN ANCHORAGE |
| AT412361B (en) * | 2002-09-03 | 2005-01-25 | Hammer Rene | METHOD AND DEVICE FOR SAVING THE MOUNTAIN AND REMOVING STOOLS, TUNNELS & DIG. |
| JP2005200893A (en) | 2004-01-14 | 2005-07-28 | Nisshin Steel Co Ltd | Steel pipe expansion type rock bolt with high bearing capacity and its manufacturing method |
| WO2007023363A1 (en) * | 2005-08-23 | 2007-03-01 | Pieter Schalk Mulder | An expansible rock bolt |
| AU2011349044B2 (en) * | 2010-12-22 | 2015-02-05 | Garock Pty Ltd | Rock bolt |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1410258A (en) * | 1919-03-29 | 1922-03-21 | Edward Ogden J | Expansion shield |
| US4284379A (en) * | 1979-07-25 | 1981-08-18 | Ingersoll-Rand Company | Earth structure stabilizer |
| GB2072784A (en) * | 1980-03-28 | 1981-10-07 | Thom R W | Anchor bolt |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3120809A1 (en) * | 1981-05-25 | 1982-12-16 | Hilti AG, 9494 Schaan | ANCHOR BOLT WITH CYLINDRICAL BOLT BODY |
| ZA906021B (en) * | 1989-08-02 | 1991-05-29 | Ingersoll Rand Co | A dynamic earth anchor,and a sleeve therefor |
-
1999
- 1999-06-04 SE SE9902065A patent/SE512834C2/en unknown
-
2000
- 2000-02-07 AU AU28400/00A patent/AU770287B2/en not_active Ceased
- 2000-02-07 EP EP00906844A patent/EP1183441A1/en not_active Withdrawn
- 2000-02-07 WO PCT/SE2000/000229 patent/WO2000075489A1/en not_active Application Discontinuation
- 2000-02-07 CA CA002371136A patent/CA2371136A1/en not_active Abandoned
- 2000-02-07 JP JP2001501743A patent/JP2003501573A/en active Pending
-
2001
- 2001-11-13 ZA ZA200109337A patent/ZA200109337B/en unknown
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1410258A (en) * | 1919-03-29 | 1922-03-21 | Edward Ogden J | Expansion shield |
| US4284379A (en) * | 1979-07-25 | 1981-08-18 | Ingersoll-Rand Company | Earth structure stabilizer |
| GB2072784A (en) * | 1980-03-28 | 1981-10-07 | Thom R W | Anchor bolt |
Also Published As
| Publication number | Publication date |
|---|---|
| EP1183441A1 (en) | 2002-03-06 |
| SE9902065L (en) | 2000-05-22 |
| JP2003501573A (en) | 2003-01-14 |
| SE9902065D0 (en) | 1999-06-04 |
| AU2840000A (en) | 2000-12-28 |
| CA2371136A1 (en) | 2000-12-14 |
| SE512834C2 (en) | 2000-05-22 |
| ZA200109337B (en) | 2003-02-26 |
| WO2000075489A1 (en) | 2000-12-14 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FGA | Letters patent sealed or granted (standard patent) |