WO2003087538A1 - Boulon d'ancrage - Google Patents

Boulon d'ancrage Download PDF

Info

Publication number
WO2003087538A1
WO2003087538A1 PCT/ZA2003/000050 ZA0300050W WO03087538A1 WO 2003087538 A1 WO2003087538 A1 WO 2003087538A1 ZA 0300050 W ZA0300050 W ZA 0300050W WO 03087538 A1 WO03087538 A1 WO 03087538A1
Authority
WO
WIPO (PCT)
Prior art keywords
rock bolt
torque
bolt
rock
deformable
Prior art date
Application number
PCT/ZA2003/000050
Other languages
English (en)
Inventor
Karel Francois Bredenkamp
Peter Frank Reinhold Farcroft Altounyan
Original Assignee
Rock Mechanics Technology Limited
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Rock Mechanics Technology Limited filed Critical Rock Mechanics Technology Limited
Priority to AU2003262192A priority Critical patent/AU2003262192B2/en
Priority to NZ535955A priority patent/NZ535955A/xx
Publication of WO2003087538A1 publication Critical patent/WO2003087538A1/fr
Priority to ZA2004/08149A priority patent/ZA200408149B/en

Links

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
    • E21D21/008—Anchoring or tensioning means
    • 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
    • E21D20/025—Grouting with organic components, e.g. resin
    • 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
    • E21D21/02—Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection having means for indicating tension

Definitions

  • This invention relates to a rock bolt and more particularly, but not exclusively, to a rock bolt and a torque limiting means for use when installing the rock bolt and which torque limiting means also provides a visual indication of the correct installation of the rock bolt.
  • a well-known and commonly applied method of installing rock-bolts involves the use of a two-component adhesive that is placed in a pre-drilled hole in a rock face.
  • the two components of the adhesive are located in two separate compartments of a plastics material capsule. Insertion and rotation of the bolt in the hole ruptures the capsule and mixes the two components of the adhesive.
  • the first method involves the use of a bolt having a circular cross-section with a textured or knurled outer surface.
  • the operatively inner end of the bolt is pushed into the hole containing a two compartment adhesive capsule.
  • the bolt ruptures the capsule for mixing of the two components previously held in the two compartments.
  • the outer end of the bolt may be formed to a non-circular section in order to mate with a matching socket on a rotation means.
  • the rotation may be simultaneous with the insertion, or be commenced after insertion. After a specified time, judged to be sufficient to mix the two components of the adhesive, the rotation is stopped and the rotation means is removed.
  • the process is critically time-dependent and assumes no variation in factors such as temperature and age of the adhesive which are known to have a major effect on the mixing and setting times; and b) there is no visible indication that the bolt has been installed correctly and is well bonded to the rock and the bolt.
  • the second rock bolt installation method involves the use of a bolt having a threaded portion at its outer end.
  • Figures 5 - 8 show the prior art apparatus for use in this method.
  • a drive-nut (7) is fixed by means of a shear-pin (8) to the outer end of the bolt (9).
  • the shear-pin (8) may be a "half pin” or a “full pin” as shown in figures 6 and 7 respectively.
  • the bolt is pushed and rotated into the hole containing the adhesive in the manner described above, up to the point at which the rotation is stopped. Commonly, two adhesives with different setting times are used in the hole, the faster setting adhesive being placed in the distal portion of the hole.
  • the faster adhesive is then allowed to set for a specified minimum time, after which the rotary torque is re-applied. If, and only if, the adhesive has set, this re-application will cause the shear- pin to break and will cause the nut to run a distance up the threaded portion to force a load-bearing plate (10) having a centrally located hole through which the bolt extends, into contact with the rock face, thus applying a degree of outwardly directed tension to the bolt. If, in spite of the setting of the adhesive, the bolt is not secure in the hole, the nut will pull the bolt out of the hole as it is tightened and this fault will be revealed by the final position of the nut on the threaded portion of the bolt.
  • a rock bolt comprising an elongate body having torque limited means at an outer end of the body, the torque limiting means having least one deformable protrusion that deforms under a predetermined torque.
  • a further feature of the invention provides for the deformable protrusion to be shaped to receive a complementary shaped chuck on a torque application apparatus to facilitate transferring torque to the rock bolt.
  • deformable protrusion to be protrusions extending in an axial direction from an end surface of the rock bolt; for the protrusions to extend across the end on diameter of the rock bolt; alternatively for the protrusions to be located at intervals on the circumference at the outer end of the rock bolt.
  • This invention extends to a method of installing a rock bolt comprising the steps of: locating an adhesive in a hole in a rock body; inserting a rock bolt in the hole; rotating the rock bolt in the hole to mix the two component adhesive using a torque limiting device until the torque limiting device stops further rotation of the bolt as a result of the setting of the two component adhesive around the rock bolt.
  • the method includes the step of designing the torque-limiting device to limit the torque applied to the bolt at a predetermined value.
  • the predetermined value of the torque to be determined from at least one or more of the group consisting of the following: the diameters of the bolt and of the hole; the length of the bolt located in the adhesive; and the type of adhesive used.
  • the method also includes a positive visual indication that the torque-limiting device has been invoked.
  • Figure 1 shows an end view of an outer end of a rock bolt
  • Figure 2 shows a side view of the outer end of the rock bolt of figure 1 ;
  • Figure 3 shows an end view of an outer end of a second embodiment of a rock bolt
  • Figure 4 shows a side view of the outer end of the rock bolt of figure 3;
  • Figure 5 shows a partial side view of an end of a prior art rock bolt having a nut and shear-pin assembly
  • Figure 6 shows an end on view of the rock bolt of Figure 5 having a "half-pin" shear-pin assembly
  • Figure 7 shows an end on view of another alternative of the rock bolt of figure 5 in which the rock bolt includes a "full-pin" shear-pin assembly
  • Figure 8 shows a side view of the rock bolt of figure 5 installed in a rock face.
  • a rock bolt is generally indicated by reference numerals 1 and 4.
  • the rock bolt 1 of figures 1 and 2 on its outer end 3 includes axially extending deformable protrusions 2 for receiving a complementary shaped chuck of a torque application apparatus, or rotation means.
  • the rock bolt 4 of figures 3 and 4 on its outer end and on its circumferential surface, has a torque limiting means in the form of deformable protrusions 6 for receiving a complementary shaped chuck of a torque application apparatus.
  • the chuck engages with the protrusions 2 and 6 to transfer torque to the bolts 1 and 4.
  • the protrusions are designed such that they deform at a predetermined torque. Upon deformation the chuck disengages from the protrusions and will no longer transfer torque to the bolt.
  • the torque application apparatus is removed from the bolt and at least part of the deformed protrusion remains on the bolt to provide a visible indication that rotation of the bolt was discontinued at a predetermined torque. In some cases, some parts of the protrusions may be sheared from the rest of the protrusion, but the fact that the protrusions gave way at a predetermined torque would be visible.
  • the apparatus described above requires the use of fast setting resin but obviates the use of shear-pin assemblies and the precision timing installation processes.
  • the fast setting resin used with the apparatus described above is necessary to ensure that the resin is not damaged before break-out occurs. If the resin does not set fast enough it will be destroyed while it is setting. The change over from mixing to setting must be rapid so that break-out occurs without destroying the resin while in an almost set state.
  • the adhesive used during the field and laboratory experiments was a two- compartment resin capsule, sold under the name "Fasloc®".
  • the larger compartment contains a mastic polyester resin and inert fillers, mainly limestone.
  • the small compartment contains further inert limestone fillers, water and benzoyl peroxide, which is the activator for the polyester resin.
  • the resin capsule is inserted in the pre-drilled hole, followed by the bolt. When the bolt is inserted and spun, it ruptures the compartments of the capsule and mixes the contents.
  • the polyester resin is activated by the benzoyl peroxide and hardens after a pre-determined latent period. The latent period is necessary for uniform mixing of the contents to take place.
  • the hardening characteristics of the polyester resin can be described in terms of two times: gel time and set time.
  • the gel time is the time, measured from start of mixing, at which the first stiffness becomes sensible.
  • the set time is a later time, at which the mastic resin has become sensibly rigid.
  • the intervening period is the cure time.
  • the test method is described in, for example, South African Standard SABS 1534: 1991.
  • the efficacy of the spin-to-breakout method relies on a very rapid increase in strength of the resin after the gel time, that is a short cure time.
  • the increase must be so rapid that the limiting torque of the break-out device is reached before significant disturbance to the setting resin mastic occurs.
  • the cure time should be as short as possible but a practical lower limit is determined by the necessary latent period, as cure time is approximately proportional to gel time for polyester resins.
  • the "Fasloc®" resin used had typical gel and set times of 9 seconds and 13 seconds respectively. These times were determined according to the test method of SABS 1534:1991. In mine use both times are shortened, and the interval reduced by the temperature rise caused by f ctional heating during mixing.
  • the fully set mastic had typical shear strengths of 25 - 26 megapascals, measured according to SABS 1534:1991.
  • the method by which the "shear" condition is achieved includes the incorporation into the lower or operatively outer end of the bolt of a visible "tell-tale” mechanism or deformable protrusion as described above, which provides confirmation that the required torque has been generated during the installation of the bolt.
  • the lower end of the bolt is formed into a star-shape, the points of which would mate with the means of rotation, and would shear off at a predetermined torque corresponding to the optimum mechanical resistance of the setting adhesive.
  • This, or a similar device could be formed with the bolt during manufacture without recourse to accurate machining, or attached subsequently as a simple casting or molding.
  • the breakout must transmit torque directly to the bolt.
  • the breakout must transmit the thrust of the bolter (means of rotation) onto the bolt.
  • the breakout must not leave any broken pieces or shards in the spanner, as they will interfere with the next installation (the operator cannot be expected to clean out any residue).
  • the spanner must also engage with the nut, to tighten it.
  • the breakout must be able to withstand normal handling during transport, without loss of function.
  • the breakout must be capable of manufacture to consistent break-out torques in the range of 5 Nm about the required break-out torque.
  • This alternative and improved method thus provides the time-dependent element, and its associated uncertainty and need for special training, from the installation procedure and also provides a confirmation of correct installation, while retaining the simplicity and hence low cost of the individual bolt.
  • the apparatus and method described herein will provide for the improved installation of bolts and allow for the use of relatively inexpensive bolts.
  • the apparatus described herein will also provide a visible indication of the correct installation of a rock bolt.
  • the invention is not limited to the precise details described herein.
  • the method can be used to install a variety of bolts or rods or any other object in any hole or bore or to another object in a number of different applications without departing from the scope of the invention.
  • many configurations of deformable protrusions may be used without departing from the scope of the invention.

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)
  • Details Of Spanners, Wrenches, And Screw Drivers And Accessories (AREA)

Abstract

L'invention concerne un boulon d'ancrage (1) comprenant un corps allongé doté de moyens de limitation de couple au niveau d'une extrémité extérieure (3) dudit corps, ces moyens de limitation de couple comprenant au moins une saillie déformable (2) qui se déforme sous l'action d'un couple prédéterminé. La déformation de la saillie déformable (2) permet d'empêcher la rotation ultérieure du boulon d'ancrage (1) sous l'action d'un appareil d'application de couple. Une caractéristique de l'invention permet de mettre en forme la saillie déformable (2) destinée à recevoir un mandrin mis en forme de manière complémentaire sur un appareil d'application de couple afin de faciliter le transfert de couple sur le boulon d'ancrage (1). D'autres caractéristiques de l'invention permettent aux saillies déformables de s'étendre dans un sens axial à partir d'une surface d'extrémité dudit boulon d'ancrage (1).
PCT/ZA2003/000050 2002-04-12 2003-04-14 Boulon d'ancrage WO2003087538A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
AU2003262192A AU2003262192B2 (en) 2002-04-12 2003-04-14 A rock bolt
NZ535955A NZ535955A (en) 2002-04-12 2003-04-14 A rock bolt
ZA2004/08149A ZA200408149B (en) 2002-04-12 2004-10-08 A rock bolt

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ZA200110206 2002-04-12
ZA01/10206 2002-04-12

Publications (1)

Publication Number Publication Date
WO2003087538A1 true WO2003087538A1 (fr) 2003-10-23

Family

ID=34104957

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/ZA2003/000050 WO2003087538A1 (fr) 2002-04-12 2003-04-14 Boulon d'ancrage

Country Status (4)

Country Link
AU (1) AU2003262192B2 (fr)
NZ (1) NZ535955A (fr)
WO (1) WO2003087538A1 (fr)
ZA (1) ZA200408149B (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008152148A2 (fr) * 2007-06-15 2008-12-18 Firep Rebar Technology Gmbh Amélioration d'un écrou d'ancrage en plastique renforcé de fibres

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4904122A (en) * 1987-08-06 1990-02-27 Dyckerhoff & Widmann Aktiengesellschaft Anchoring device, such as a rock anchor
US5282698A (en) * 1992-06-03 1994-02-01 The Eastern Company Threaded fastener, method of fabrication thereof and method of supporting a mine roof using such a fastener
WO1995000744A1 (fr) * 1993-06-28 1995-01-05 Jeffrey Robert Ferguson Nouveaux boulons d'ancrage dans la roche
US5873689A (en) * 1997-07-03 1999-02-23 Milad Mansour Low torque threaded fastener and mine roof support system using such a fastener

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4904122A (en) * 1987-08-06 1990-02-27 Dyckerhoff & Widmann Aktiengesellschaft Anchoring device, such as a rock anchor
US5282698A (en) * 1992-06-03 1994-02-01 The Eastern Company Threaded fastener, method of fabrication thereof and method of supporting a mine roof using such a fastener
WO1995000744A1 (fr) * 1993-06-28 1995-01-05 Jeffrey Robert Ferguson Nouveaux boulons d'ancrage dans la roche
US5873689A (en) * 1997-07-03 1999-02-23 Milad Mansour Low torque threaded fastener and mine roof support system using such a fastener

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2008152148A2 (fr) * 2007-06-15 2008-12-18 Firep Rebar Technology Gmbh Amélioration d'un écrou d'ancrage en plastique renforcé de fibres
DE102007028267A1 (de) * 2007-06-15 2008-12-18 Firep Rebar Technology Gmbh Verbesserte Ankermutter aus faserverstärktem Kunststoff
WO2008152148A3 (fr) * 2007-06-15 2009-03-05 Firep Rebar Technology Gmbh Amélioration d'un écrou d'ancrage en plastique renforcé de fibres
DE102007028267B4 (de) * 2007-06-15 2011-04-28 Firep Rebar Technology Gmbh Verbesserte Ankermutter aus faserverstärktem Kunststoff
AU2008263816B2 (en) * 2007-06-15 2013-05-30 Firep Rebar Technology Gmbh Improved anchor nut made of fiber-reinforced plastic
RU2484318C2 (ru) * 2007-06-15 2013-06-10 ФиРеП РЕБАР ТЕКНОЛОДЖИ ГМБХ Усовершенствованная анкерная гайка из армированного волокном полимера

Also Published As

Publication number Publication date
NZ535955A (en) 2006-04-28
AU2003262192B2 (en) 2008-03-06
AU2003262192A1 (en) 2003-10-27
ZA200408149B (en) 2005-12-28

Similar Documents

Publication Publication Date Title
US4303354A (en) Mine roof bolting
KR840001662B1 (ko) 갱도용 루우프 볼트
US4861197A (en) Roof bolt system
US6484471B2 (en) Adhesive fixed anchors
US5299474A (en) Tamper resistant device for the application of preselected torque to screws and the like
US4413930A (en) Method and apparatus for combining resin bonding and mechanical anchoring of a bolt in a rock formation
US4386877A (en) Mine roof bolting
US4193715A (en) Mine roof support method and apparatus
US5073064A (en) Method and apparatus for retorquing an installed mine roof bolt
CA1252319A (fr) Douille d'expansion a temoin de force de prise
US4122681A (en) Mine roof support assembly
US4746248A (en) Anchor bolt assembly
US4708550A (en) Resistance between nut and bolt
AU2003262192B2 (en) A rock bolt
GB2273538A (en) Rockbolt tensioning
AU2003244593B2 (en) Universal setting tool for adhesively bonded rebar and threaded rod anchors
WO1992003262A1 (fr) Dispositif de serrage pour attache filetee
US20120155970A1 (en) Mine Roof Bolt With End Fitting
US5222835A (en) Resin-mixing article for mine roof anchor
AU2008263816B2 (en) Improved anchor nut made of fiber-reinforced plastic
US4404875A (en) Installer drive unit for chemical anchor
GB2211259A (en) Installation of tensioned rockbolts
AU2008351618B2 (en) Improved sliding anchor
EP0259021B1 (fr) Assemblage de boulon d'ancrage
GB2118234A (en) Cavity wall tie for existing walls

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NI NO NZ OM PH PL PT RO RU SC SD SE SG SK SL TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
WWE Wipo information: entry into national phase

Ref document number: 2004/08149

Country of ref document: ZA

Ref document number: 200408149

Country of ref document: ZA

WWE Wipo information: entry into national phase

Ref document number: 2003262192

Country of ref document: AU

WWE Wipo information: entry into national phase

Ref document number: 3145/DELNP/2004

Country of ref document: IN

WWE Wipo information: entry into national phase

Ref document number: 535955

Country of ref document: NZ

122 Ep: pct application non-entry in european phase
WWP Wipo information: published in national office

Ref document number: 535955

Country of ref document: NZ

NENP Non-entry into the national phase

Ref country code: JP

WWW Wipo information: withdrawn in national office

Ref document number: JP