mines01.pdf

HealthandSafetyExecutive

Guidanceontheuseofrockboltstosupportroadways incoalmines

Thisguidanceonthesupportofmineroadwaysincoalminesbyrockbolts wasprepared,inconsultationwiththeHealthandSafetyExecutive(HSE), bytheDeepCoalMinesIndustryAdvisoryCommitteewhichwas appointedbytheHealthandSafetyCommissionaspartofitsformal advisorystructures.Theguidancerepresentswhatisconsideredtobe goodpracticebymembersoftheCommittee.Ithasbeenagreedbythe Commission.

Undercurrentlegislationrockboltsmayonlybeusedastheprincipal supportofmineroadwaysincoalminesifHSEhasgrantedexemption fromtherequirementsofsection49(i)oftheMinesandQuarriesAct1954 andregulations13and14oftheCoalandOtherMines(Support) Regulations1966.Itwillbeaconditionofanysuchexemption,tocarryout therockboltingoperationsinaccordancewiththeguidance.

Thiswebonlyversionreplacesthe1996editionofthisguidance.

Introduction

1 Thisdocumentprovidesguidanceonthesafeuseofrockboltstosupport roadwaysincoalmines.Itisaimedatcoalminemanagers,supervisorsandmine workerswhohaveresponsibilityforrockboltsupportoperations.

2 Theguidanceappliestotheplacesincoalmineswhererockboltsprovidethe principalsupportandmayinclude:

developmentheadingsandjunctions; coalfacedevelopmentdrivages; retreatdistrictgateroadsincludingthefaceTeejunction; roomandpillarcoalproductiondistricts; specialpurposedrivages,egtohouseequipment.

3 Examplesofplaceswhichmaynotbesuitableare:

goafscours; gateroadsservingadvancingfaces; crossmeasuresdrifts; headingsformedbyshotfiringoffthesolid.

4 Roadwaysimmediatelynexttogoafsarenotsuitableforsupportbyrockbolts andarenotcoveredbythisguidance.

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Definitions

5 Thefollowingdefinitionsapplythroughoutthisguidance:

Freestandingsupports aresupportswhichareerectedbetweenthefloor androof,egarches,girders,hydraulicpoweredsupports,chocks/cribs,props andbars.

Inspectionofficials areappointedtocarryoutinspectionsunderregulation 12oftheManagementandAdministrationofSafetyandHealthatMines Regulations1993(MASHAM).

Membersofthemanagementstructure aretheminemanagerandother peopleappointedtotheminemanagementstructureunderregulation10of MASHAM.

Principalsupportiswhererockboltsprovidethesupportevenwheretheyare usedinconjunctionwithsupplementarysupport.

Rockbolt isabarinsertedintotherooforsideofaroadwaywhichisusedin conjunctionwithfullyencapsulatingresinorsomeotherappropriatesubstance toprovidereinforcementoftheroofandsidesofaroadwayorworkingplacein a mine.

Rockboltedheading/roadway isaheading/roadwayinwhichrockbolts providethemainmeansofsupport.

Geotechnicalassessmentandsiteinvestigation

6 A geotechnicalassessmentandsiteinvestigationarefundamentalprerequisites forthedesignofasupportsystem.Theresultsneedtoberecorded.

7 Themanagershouldappointasuitablyqualifiedandcompetentpersonto undertakeandrecordtheresultsofageotechnicalassessmentandonthebasisof theassessmentdesignasafeandsuitablerockboltsystem.Asuitablequalification forsuchapersonwouldbeacharteredengineer,orequivalent,whohashadthree yearsappropriateexperienceinworkrelatedtominestratacontrol.Forthe purposesofthisbooklet,thispersonisreferredtoasthedesignengineer.

8 Theassessmentneedstotakeintoaccountallfactorslikelytoaffectthe performanceofthesupportsystemduringthelifeoftheroadway.Itshouldalso considerthestratadeformationprocessestobecontrolledandtheactionofthe boltingsystemincontrollingthedeformation.

9 Theareacoveredby theinvestigationneedstobedefinedandanysubsequent supportsystemdesignconfinedtothatarea(seeparagraph13).Theassessment needstoincorporateallrelevantfeaturesfromtheinitialdevelopmentand throughoutitsworkinglife.

10 Thesiteinvestigationneedstoincludereferencetothefollowing:

geology: includingthestratasection,rockproperties,faults,cleat,parting planes,presenceofwateroranysubstancelikelytoflow,boreholeinformation andgradients.Allfactorsneedtobecorrelatedrelativetothemininghorizon;

stress: thedirectionandmagnitudeofthestressfieldcomponentsforpremining,mininginducedconditionsandinteraction;

pillardesignandeffects: theassessmentneedstoincludedrawingsand diagramstoillustratepotentialriskareas;

environmentaleffects: theeffectsofambienttemperature,minewaterand associatedimpurities;

Guidanceontheuseofrockboltstosupportroadwaysincoalmines 2 of32pages


bondstrength: measuredbyshortencapsulationpulltestsusingthe proposedrockboltingmaterialsandcomponents(seeAppendix1).Thetests needtobecarriedoutforallmajorroofhorizonchangeswithinthelengthof theproposedrockboltandtheeffectsofwetflushingoralternativedustcontrol systemonthebondstrengthdetermined.Thebondstrengthneedstohavea minimumvalueof130kNewtons,forabondlengthof0.3m,over50%ofthe boltlength;

standuptime: dilationrelatedtodistancefromtheface(seeAppendix9).

11 Theassessmentneedstobesignedbythepersonorpeoplecarryingoutthe investigation.

12 Ifrockboltingistobeconsideredelsewhereinthesameseam,sufficient investigationneedstobecarriedouttoconfirmthattheconditionsaresimilarto thoseatprevioussites.Ifconfirmed,theinformationestablishedatthosesitesmay beusedagainandreferencemadetotheearliersiteinvestigation.

13 Asupplementarysiteinvestigationshouldbecarriedoutwheneverthereisa majorchangeinthemethodofwork,lithology,structureorconditions.

Supportsystemdesign

14 Wherethesiteinvestigationandgeotechnicalassessmentindicatesthatthe strataissuitablefortheuseofrockboltsasthemainmeansofsupport,asupport designneedstobeprepared.Whereanexistingdesignhasalreadybeenproved, referencetoitmaybemadeforotherroadwaysofsimilardimensionsinthesame seam.Thisisprovidingthatsuitableandsufficientstepsaretakentoshowthatthe geologicalconditions,rockpropertiesandstressfieldsatbothsitesare substantiallysimilar.

15 Adesignengineerwillpreparetheinitialdesignoftherockboltingsystemon thebasisoftheresultsofthesiteinvestigation.Asaminimum,thedesignneedsto takeaccountofthefollowing:

theprofileoftheheading; thelengthofrockboltstobeusedintheroofandribs.(Therecommended

minimumlengthintheroofis1.8m); thedensityofrockboltsintheroof.(Therecommendedminimumdensityof

supportis1bolt/sqmbutsiteinvestigationmayindicateaneedforhigher densities);

theplacingofrockbolts.Itisrecommendedthatboltstobeusedintheroof areinstalledasclosetothefaceoftheheadingaspossibleandassoonas practicableafterexposureoftheroof;

thetypeofrockbolt.Allboltstobeusedintheroofshouldbefullcolumnresin bonded;

holesdrilledforroofholes.Theyneedtobeformedinsuchawaythatthe bondstrengthparametersareachievedandthefinishedholediameterdoes notexceedthenominalboltdiameterbymorethan7mm;

a systemofsupportfortheroadwaysides,wheretheinitialassessment demandstheprovisionofsuchsupport.

16 Whentheinitialdesignhasbeencompleted,documentationneedstobe prepareddetailingthe:

useoftheroadway/junction; freestandingsupplementarysupportifapplicable; layoutanddimensionsoftherockboltingpattern;



specificationofrockboltingconsumablestobeused; methodofwork; maximumfacetoboltdistance;and designverificationmonitoringsystem.

17 Thedesigndocumentshouldbesignedbythedesignengineerandwillform thebasisofthemanagerssupportrules.

Designverificationmonitoring

18 Theinitialdesignofthesupportsystemneedstobeverifiedbycomprehensive monitoring.

19 Comprehensivemonitoringfordesignverificationinvolvesdetailed measurementofroofdilationandrockboltloads.Itmayalsoinvolvedetailed measurementofribdilationandroadwayinternalmeasurements.Measurementof roofdilationneedstobetoanaccuracyof1mmataminimumof15pointsovera heightofatleast7m.Rockboltloadsneedtobemeasuredonaminimumoffour rockboltsdistributedacrosstheroadwaysection.Detailsoftheinstrumentsused areinAppendix2and3.

20 Wherechangesareproposedinroadwaydimensionsormethodsofworking, orwheretheyareobservedtooccuringeotechnicalconditions,furtherdesign verificationmonitoringneedstobecarriedouttoassessthecontinuedvalidityof thedesign.

21 Aplanneedstobepreparedshowingdetailsofthesitingofmonitoringstations inrelationtogeologicalandminingfeaturesandincludedetailsofthe instrumentationateachstation.Eachmonitoringstationneedstobegivena uniqueidentificationcodewhichcanbeusedtoidentifyreadings.

22 Monitoringinstrumentsneedtobereadbysuitablytrained,competentand authorisedworkersusingappropriateequipment.

23 Themonitoringresultsandinterpretationneedtoberetainedforfuture reference.

24 Theresultsofthemonitoringneedtobeinterpretedbythedesignengineer. Anyactionsorchangesrecommendedneedtobeincludedinthedesign documentation,andifappropriate,inthesupportrules.

Routinemonitoringandrecordingscheme

25 Whererockboltsareusedtosupportmineroadways,themanagerneedsto prepareaSchemefortheroutinemonitoringofroadways.

26 Themanagerneedstoappointasuitablyqualifiedandcompetentpersonto implement,auditandcoordinatethescheme.Asuitablequalificationwouldbea HigherNationalCertificateinaminingrelatedsubjecttogetherwithatleastsix monthsrelevantexperienceofstratacontrolactivitiesinacoalmineandthe completionofatrainingcourseinrockbolting.Forthepurposesofthisguidance thispersonisreferredtoastherockboltingcoordinator(coordinator).Where appropriate,sufficientsuitablytrainedandcompetentpeopleneedtobeappointed toassistintheperformanceoftheseduties.

27 Themanagersschemeneedstospecifythe:



proceduresfortheauditingofroutinemonitoringdevicesinrockbolted roadways;

equipmenttobeused; dutiesofindividualsandtherequiredplans,schedulesandreports.

28 Theschemeneedstorecognisethe:

needtomonitorandreportphysicalchangesaffectingthesecurityofthe supportsystem;

needtotakeremedialmeasures; maximumlevelsofmovementallowedonthemonitoringdevicesbeforeaction

isrequired; actionstobetakenandthepersonresponsiblefortakingtheaction.

Routinemonitoringdevices

29 Twomaintypesofmonitoringdeviceareutilisedfortheroutinemonitoringof rockboltedroadways.Thesearedualheighttelltalesandmultihorizon extensometers.

Dualheighttelltales

30 Dualheighttelltalesgivevisualindicationofroofdilation.Theconstruction, installationprocedureandmethodofreadingdualheighttelltalesisshownin Appendix4.Thetelltalesneedtobeinstalled:

toatleasttwicetheheightoftheboltlengthor4.8m,whicheveristhegreater; atintervalsofnotgreaterthan20mmaximumdistance; ateveryjunction; atareasofknownorsuspectedinstability; atareasoflikelyinteractionfromoldandpresentworkings,andenlarged

excavations.

31 Telltalescanalsobesetatincreasedfrequenciesbypeopleworkingonsiteor throughsupervisoryormanagerialinstruction.

32 Telltalesneedtobeinstalledasnearverticalaspossibledrilledclosetothe centreoftheroadway,andasclosetothefaceoftheheadingaspracticable,oras directedbythecoordinator.

33 Atthesiteofeverytelltaleahighvisibilitysignneedstobeplacedbearinga uniquereferencecodetoenablethetelltaletobeeasilyidentifiedforreportingand recordingpurposes.

34 Alltelltaleswhichbecomedefective,obscuredoroutofrangeneedtobe replacedasquicklyaspossibleatthesameheightinthesameholeor,whenthisis notpossible,drillanewholeincloseproximity.Specificdutiesunderactionlevels mayalsoberequired.Whensomeonereplacesatelltale,thereadingoftheold telltaleneedstoberecordedandreportedinwritingthatithasbeenreplaced.This informationisthengiventoboththecommandsupervisorfortheareaandthecoordinator.Allreplacementtelltalesneedtobetoauniquecolourscheme.

35 Telltalesneedtobereadbysuitablytrainedandcompetentpeopleby:

observingthecolouredbands;or measuringthegraduationlines;orby electronicsystemstoamannedcontrolpoint.



36 Theseniorofficialsattentionneedstobedrawntoanytelltalemovementin excessof25mmoneithertheAorBindicatororatthemanagersrulesaction level,whicheveristhelowerfigure.Managersrulesshouldalsodetailactionson theratesofmovementappropriateforthespecificminesite.

37 Forrecordingpurposesanytelltalereadingneedstoberelatedtotheunique referencecodeinparagraph33.

Multihorizonextensometers

38 Multihorizonextensometersaremonitoringdevicesdesignedtobeinstalledby a suitablytrainedandcompetentpersonandprovidedetailedinformationonroof dilationtoaminimumdistanceof7.0maboveroofheight.

39 Therearetwomaintypesofextensometer:

sonicextensometer; multiwireextensometer.

40 Theconstructionandinstallationofthesonicextensometerisshownin Appendix3andthatofthemultiwireextensometerinAppendix5.

41 Installmultihorizonextensometersforroutinemonitoringatmaximumintervals of200minanydirectionoratcloserfrequencywhereconditionsdemand.

42 Installmultihorizonextensometersforroutineroofmonitoringinverticalholes, drilledclosetothecentreoftheroadwayandasclosetothefaceoftheheading aspracticable,unlessdirecteddifferentlybythecoordinator.

43 Atthesiteofeverymultihorizonextensometer,placeasignbearingaunique referencecodetoenableittobeeasilyidentifiedforreportingandrecording purposes.

44 Multihorizonextensometersneedtobereadbysuitablytrained,competent andauthorisedpeopleusingtheappropriateequipment.Forrecordingpurposes, anyreadingneedstoberelatedtotheuniquereferencecode.Theinformationmay beelectronicallytransmittedtoacontrolpoint.

45 Replaceallroutinemonitoringmultihorizonextensometerswhichbecome defective,obscuredoroutofrangeasquicklyaspossible.Whereanymultihorizon extensometerisreplaced,amendthesigntoindicatesuchreplacement.The commandsupervisorfortheareaandthecoordinatorneedtobenotifiedin writingofanyreplacements.

Plansandschedules

Planofrockboltedroadways

46 Aplanneedstobepreparedandmaintainedtoindicatethepartsofthemine whererockboltsareusedasthemainmeansofsupport.Posttheplanwhereit canbeeasilyseenbyallthosewhohaveresponsibilitiesunderthemanagers schemebeforetheygounderground.Makesureitisreviewedweekly.

Scheduleofmeasurementzonesandmeasurementfrequency

47 Ascheduleneedstobemaintainedatthemine,listingallrockboltedroadways andtherequiredfrequencyofmeasurementofmonitoringdevicesinthose



roadways.AnexampleisshowninAppendix6.Therecommendedfrequencyof measurementsisasfollows:

dualheighttelltaleswhichareinstalledinroadwayswithinInbyedistrictsneed to beobservedandreportedoneachshiftbytheinspectionofficialand measuredandrecordedatleastweekly;

allroutinemonitoringdevicesinstalledinsectionsofroadwayswhichareareas ofknownorsuspectedinstabilityneedtobemeasuredandrecordedatleast daily;

measureandrecordallotherroutinemonitoringdevicesatthemineatleast onceeachmonth;

whereanyadversereadingortrendisrecorded,measurementandrecording needtobecarriedoutforeachshift.

48 Divideeveryrockboltedareaofthemineintomeasurementzonestoenablethe systematicmeasurement,recordingandauditingofroutinemonitoringdevicesat theprescribedfrequency.

Inspectingofficialstelltalechecklists

49 Produceatelltalechecklistforeverydistrictcontainingrockboltedroadways andupdateitatleastweeklytotakeaccountofnewandreplacementtelltales.An examplechecklistisshowninAppendix7.

Dutiesofpeopleinrelationtotheminemonitoringscheme

Minemanager

50 Theminemanagerensuresthatamonitoringschemeisinplacetomaintain stabilityofmineroadwayssupportedbyrockbolts.Themanagerappointsacoordinatortomanageandcoordinatethescheme.

51 Intheabsenceofthecoordinator,themanagercanappointasimilarlytrained andcompetentpersontoactasasubstitute.

52 Themanagerappointssufficientsuitablytrainedandcompetentpeopleand grantsfacilitytoensurecompliancewiththescheme.

53 Themanagersetsthelevelofmovementatwhichactionistobetakenand specifiestheremedialmeasurestobetakenatthoselevels.

Minerockboltcoordinator

54 Thecoordinatorensuresthatthemanagersschemeforroutinemonitoringof rockboltedroadwaysisfullyimplementedandkeepsthemanagerinformed,sothat theschemeisregularlyupdated.

55 Thecoordinatorensuresthatcommandsupervisorsandinspectionofficials havetherequisiteinformationtoenablethemtofulfiltheirdutiesinrelationto supportofmineroadways.

56 Thecoordinatorhasthefollowingspecificduties:

toensurethatroutinemonitoringdevicesareinstalledorreplacedtothe standardandfrequencyspecified;

toensurethatthescheduleofmeasurementzonesandmeasuringfrequencyis maintained;



toensurethatallrelevantworkersareinformedofthecurrentactionlevelsand thattheappropriateremedialactionsarebeingtaken;

to reporttothemanagertheresultsofremedialactionsandcontinued requirementsuntilapositionofstabilityisrecorded;

to ensurethatallroutinemonitoringdevicesattheminearemeasuredand recordedatthefrequencyspecifiedinthescheme;

toensurethatthemanagerortheirnominatedrepresentativeisinformedofany abnormalresultsonadailybasis;

tocollateandassessallinformationondefectsandabnormalitiesaffectingthe stabilityofrockboltedroadways.Thecoordinatorneedstoconferwith appropriatemembersofthemanagementstructureandadvisethemofthe requiredremedialaction;

toensurethatrecordsofallmeasurementsofroutinemonitoringdevicesand copiesoftheirreportstothemanageraremaintainedatthemineforatleast threeyears;

toensurethatanyreportedgeotechnicalfeaturesorchangeswhichmayaffect stabilityarebroughttotheattentionoftheappropriatemembersinthe managementstructure.

Inspectionofficials

57 Whereaninspectiondistrictincludesareasofrockboltedroadway,an inspectionofficialshouldvisuallyexamineeverydualheighttelltaleintheroadway andrecordanydefectsandabnormalitiesinthestatutoryreport.

58 Theinspectionofficialneedstoensure:

theyarefamiliarwiththepresenceofanyrockboltedroadwayswithinthat district;

theyhavetheappropriatetelltalechecklistsforthatdistrict; theyarefamiliarwiththeactionlevels;and duringtheirinspection,they:

readeverytelltalebyobservingthecolouredbandsandrecordonthe checklisttheconditionofeverytelltalewhichhasregisteredchange;

examinetheconditionofeverytelltaleandexaminewhethertheyareproperly identified;

ensuretelltalesareinstalledattheappropriatefrequencyandreplacedwhen necessary;

examinetheconditionofthesupportsystem;

examineforanygeotechnicalchangeorfeatures;

takeactiononanyadverseaspectfound.

59 Iftheinspectionofficialbelievesanydefectorabnormalityaffectingthestability ofarockboltedroadwayneedsmoreattention,theyshouldinformrelevantpeople assoonaspossible.Suchpeoplearetheappropriatecommandsupervisorsand theseniormembersofthemanagementstructureondutyatthemine.

60 Attheendoftheinspectionofficialsshift,thefollowinginformationshouldbe includedintheinspectionreport:

defectsorabnormalitiesaffectingthestabilityoftherockboltedroadways; defectsinthemonitoringsystem; telltalesreplacedduringtheshift; remedialworkcarriedout; remedialworkrequired; geotechnicalchange;and thosewhohavebeeninformedofthesematters.



61 Attheendoftheshifttheyshouldsubmittheircompletedinspectionreport andtelltalechecklistasdesignatedbythemanager.

Surveyor

62 Thesurveyorshouldensurethattheplanofrockboltedroadwaysismaintained, reviewedandupdated.Theyhavetoinformthemanagerandthecoordinatorof anypredictedgeotechnicalchangeswhichmayaffectthestabilityofrockbolted roadways.

Operators

63 Operatorsshouldinstallrockbolts:

tothemanagerssupportrules; tothemanagersCodeofPractice; totheinstructionofacoordinatororofficial; accordingtothemanufacturers/suppliersinstructions.

Training

64 Allworkersinvolvedwithrockboltingneedtoreceivesuitabletraining(see Appendix8).Recordsofsuchtrainingareissuedtotheworkersinvolvedon successfulcompletionofthetraining.Additionaltrainingneedstobeprovided where circumstanceschangeandforrefresherpurposes.

Consumableitems

65 Allconsumableitemsformingpartoftheroadwaysupportsystemspecifiedin paragraphs1416mustbesuitableforthepurposewheninstalledincompliance withinstructionsprovidedbythesupplier.Aproductwouldberegardedassuitableif:

ithadreceivedanacceptancenumberundertheBritishCoalCorporations proceduresfortheAcceptanceofStrataReinforcementMaterialsand Equipmentbetween1April1992and30June1995;or

itcanbeshown,bymeansofindependentlyconductedandassessedtype testing,tomeetthecriteriasetoutinthedraftBritishStandardforStrata reinforcementsupportsystemcomponentsusedincoalmines; or

wherenocriteriaasreferredtoaboveexist,that: alaboratorytestprogrammeissetouttosimulate,ascloselyasis practicable,operationalconditions;

teststothisprogrammeareconductedbyanindependentaccreditedtest houseandareportisprepared;

theresultsofthetestareassessedindependentlyandfoundtobe satisfactory;

anassessmentofanyrisktosafetyand/orhealthhasbeencarriedout; thesupplieroftheproductisinpossessionofaletter,fromtheassessing body,settingouttheconditionsunderwhichtheproductmaybeused underground.Fieldtrialsmayberequiredtovalidateperformance.



Appendix1UndergrounddeterminationofbondstrengthSteelrockbolt/resinsystemShortencapsulationpulltest

Introduction

Theshortencapsulationpulltestisusedtomeasuretheperformanceofa rockbolt/resin/rocksystem.Thetestisperformedundergroundandistheultimate prooftestofabolt/resin/rocksystem.Itshouldreplicatetheprocedures, consumablesandequipmentinuseforthesupport.

Briefdescription

A seriesofholesaredrilledtovaryingdepthsandboltsoftherequiredlengthare installedwithashortresincapsuletogiveanencapsulatedboltlengthofnotmore than300mm.Thepulltestneedstobeperformedafteracuringperiodofatleast 1 hourandnotmorethan24hours.Afterthistimeanaxialloadisappliedtothe endoftheboltandtheboltextensionmeasured.Theloadisappliedupto220kN oruntilthemaximumloadofthesystemhasbeenachieved,whicheveristhe greater.

Procedure

Equipment

Boreholemicrometer. Cabletiewrapsforpreparationofshortresincapsules. Knife. Tapemeasure. Pulltestequipmentcomprising:

asuitablehydraulicram; pressuregaugecapableofreadingpressuresequivalenttoaloadof300kN toanaccuracyofbetterthan10kN;

dialgaugecapableofreadingto0.01mm;

monopodtosupportdialgauge;

bearingplate;

drawbar;

shimsofvaryingthickness.

Note: Theramandpressuregaugeneedtobecalibratedregularly(ataminimum ofthreemonthlyintervals)toproduceaplotofpressureversusforceapplied.

Numberoftests

A minimumoftwotestsneedtobecarriedoutateachofthechosenroof horizons.Asanexample,fora2.4mbolt,thesehorizonswouldnormallybeat 600,1200,1800and2300mm.Ifsignificantchangesingeologyoccurwithinthe boltedhorizon,furthertestsneedtobecarriedoutatotherhorizonstodetermine theirinfluence,ifany,onthebondstrengthofanyproposedboltingsystem.

Boltpreparation

Theboltlengthneedstobeatleast40mmlongerthantheholelengthtoallowfull engagementofthedrawbaronthethreadedendofthebolt.Alltestbolts, includingfulllengthbolts,needtobecutsquaretotheboltaxis.



Location

Placepulltestboltsascloseaspracticabletothefaceoftheheading.Choosea sectionofreasonablyflatroofwhichisnotsubjecttospalling.Thetestboltsshould notbeinstalledthroughmeshorstrapsandneedtobeatleast300mmapart. Boltsofthesamelengthneedtobeseparatedbyatleast1m.

Capsulepreparationandmeasurementofembedmentlength

Methodusingreamedouthole

Therockboltholeneedstobedrilledtothetopofthetesthorizonusingthe requiredbitandthenreamedouttoalargerdiametertowithin300mmofthehole depth.Thisprocedurewillensureaccurateknowledgeoftheencapsulationlength (Figures1aand1b).

Whentestinga22mmboltinanominal27mmdiameterhole,anembedment lengthof300mmisusuallyachievedwithacartridgelengthof170mm.

Preparethe170mmlongtestresincapsulesfromthefastsettingresinfoundin theheadingusingthetiewrapsandremovingtheexcesscapsule.Insertthebolt andresincartridgebyhandtoensuretheresincartridgeisnottornonthelip betweenthelargerandsmallerholes.Placealocatingmarkonthebolt correspondingtothecorrectinsertiondepthofboltandcartridgetoensurecorrect insertionintothesmallerhole(Figure1a).

Methodusingnonreamedhole

Theremaybeoccasionswhenthemethodsetoutinthelastthreeparagraphsis notappropriateforthesite.Thisisparticularlytruewhendrillingweakmudstones andflushingwithwater.Inthiscasequantitiesofthemixtureofmudstoneand watercanbeforcedbythereamerbitintothe300mmlongtestsection contaminatingthesurfaceofthetestborehole.Thiscoatingmaythenreducethe mechanicallockbetweenresinandrockleadingtospuriouspulltestresults.In thesecircumstancesreplacethereamedoutholemethodbythefollowing:

Drillholetolengthusingstandardbit. Measure:boreholediameter;boltdiameter;resincapsulediameter. Determinetheresincapsulelengthtoproducenotmorethan300mmbolt

encapsulationusingtheformula:

Capsulelength=(HoleD2 BoltD2 ) x encapsulatedlength CapsuleD2

Preparetestresincapsulesofthecalculatedlengthfromtheresinusedinthe headingusingthetiewrapsandremovingtheexcesscapsule.

Holepreparation

Thesamedrillingmachineandoperatorneedtobeusedthroughoutthetests.Use thedrillbitspecifiedforthesitefordrillingthetestholes.

Useanewbit. Measurethebitdiameterbeforeeachtest. Usewetdrillingunlessclearlystipulatedotherwise. Drillholestotherequireddepth. Usingaboreholemicrometer,determinethemeandiameteroverthetop

300mmoftheholebytakingseveralreadingsinthisregion.



150 - 200 mm Cartridge (length not critical)

300 mmTesthorizon

Tape checks that the cartridge and boltare correctly inserted into small hole

300 mm Test horizon

Hole diameter over test horizon (typically 26 mm to 28 mm)

Jack

Enlarged hole(>30 mm)

Resin in largerhole has negligibleeffect on loadtransfer

Figure1aMethodofcheckingcorrectinsertionofboltintosmallhole

Figure1bArrangementofboltwithinsmallholeandenlargedholetoensure300mm encapsulation.



Boltinstallation

Thesurfaceconditionofthetestsectionofboltneedstobefreefromrust,grease, paint,dirtoranyothersurfacecontaminant.

Insertthecapsuleandboltandpushthecapsuletothebackofthetesthole byhand.

Raisethemachinetotheboltandengage. Thrustandspintheboltslowlytothebackoftheholetakingthreetofive

seconds,afterwhichtheboltshouldbespunforatleastafurtherfiveseconds. Waitforasuitableperiod,30secondsforfastsetresinforexample,andthen

lowerthemachine. Identifythetestboltforlength,bymarkingtheroofand/ormakingasiteplan.

Pulltesting

Boltsneedtobepullednosoonerthanonehourandnolaterthan24hoursafter installation.Thisistoensurethattheresinhastimetocureandthatnotimedependentroofmovementmechanicallylockstheboltinthehole.

AssembletheequipmentasshowninFigure2.Aligntheramalongtheaxisoftheboltandmakesuretheboltisnotincontactwiththewallofthehole.Thisis bestachievedbyfirsttrimminganyloosematerialfromaroundthemouthofthe holeandthenaligningtheassemblybywedgingsteelshimsbetweentheroofand bearingplate.Whentheassemblyisfullyaligned,thestemofthedialgaugeis locatedintotheidentontheendofthepullbarsothatitisalsoinlinewiththeboltaxis.

Atleasttwoskilledoperatorsarerequiredtooperatethepumpandtoreadthedialgauge.

Applytheboltloadslowlyandsmoothlyandwithoutpause.Theboltdisplacement needstobenotedat10kNintervals.



Embedded length300 mm

Bolt

Hydraulic ram

Dial gauge

Nut andbearing

plate

Hydraulic pumpwith force indicator

Drawbarcoupler

Figure2 Equipmentforpulltest



Analysis

Computersoftwareisavailabletocalculatetheyieldbondstressofthe rock/resin/boltsystem.

Thesoftwareisbasedonthefollowingcalculations:

EExtensioninbolt= FxLF

S x x D2

4

Bonddisplacement=Measuredboltdisplacement(boltextension+drawbarextension)

Where:

F = Appliedforce(Newtons) LF = Boltfreelength(mm)=boltlength(encapsulatedlength+length

inpullbar) Es = Youngsmodulusforsteel(206000MPa) BoltD = Nominalboltdiameter(mm)

A graphofappliedforce(kN)vbonddisplacement(mm)needstobeplotted.The bondstrengthistheappliedforceatwhichtheslopeofthegraphfallsbelow20kN/mm.Wherethebondlengthisnot300mm,theresultsneedtobe correctedtoa300mmbondusingtheformula:

Correctedbondstrength(kN)=measuredbondstrength(kN)x300 encapsulationlength(mm

Thereportedresultsneedtoincludetheaveragemeasuredtestholediameterand theencapsulationlength.Asuggestedformatforapulltestlogsheetisshownin Figure 3.

Testrequirements

Ingeneral,theaveragebondstrengthover50%oftheholelengthneedstoexceed 130kNforabondlengthof300mm.Thisvalueisequivalenttoabondstressof5 MPaforatestholediameterof27.6mm.



PULL

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Figure3 Anexampleofapulltestlogsheet



Appendix2Straingaugedrockbolts

Description

Straingaugedrockboltsareusedtomeasureaxialandbendingstrainsimposedon therockboltswheninstalledinaroadway.Thestraingaugedboltsreplacesomeor allofthenormalboltsintheboltingpattern.

Strainsaremeasuredusingpairsofstraingaugesattachedtooppositesidesofthe rockboltsatintervalsalongitslength.Fromthemeasuredstrains,theboltmean strainsandstraindifferencescanbecomputedatthestraingaugepositionand boltloadprofilesandbendingmomentsestimated.

Theboltsmustbecorrectlyinstalledandalignedtogiverepresentativeresults.

Specification

Thestraingaugedboltsneedtobemanufacturedfromactualrockboltsasusedin thesupportsystem,ie:

samesteel; samesurfaceprofile; samelength,diameters,threadetc.

Installthestraingaugesdiametricallyopposedinalignedpairsatintervalsalongthe axisofthebolts.

Makesurethemaximumdistanceofthefirstpairfromeachendoftheboltdoes notexceed0.2m.Makesurethemaximumaxialdistanceapartofgaugepairs doesnotexceed0.3m.

Theminimumnumberofgaugepairsforvariousboltlengthsaretherefore:

1.8mbolts6pairs; 2.1mbolts7pairs; 2.4mbolts8pairs; 2.7mbolts9pairs.

Forboltlengthsgreaterthan2.7m,thedistancebetweengaugepairsmaybe increasedbeyond0.3m,providingaminimumofninegaugepairsareinstalled.

Thestraingaugedboltshavetobecapableofbeinginstalledinanidentical mannertothatusedfornormalbolts.Makesuretheyareprovidedwithasuitable connectortoallowreadingofthegaugesbeforeandafterinstallation,using suitablemonitoringequipment.Theboltsneedtobesubjectedtotestingand qualitycontrolproceduresduringandaftermanufacture.

Installation

Installthestraingaugedboltsaspartofthenormalcycleofboltingoperations usingthesameequipment,consumablesandboltingpatternsasfornormalbolt installation.Readtheboltsshortlybeforeinstallationandagainassoonaspossible afterinstallation.Duringinstallationaligntheboltssothatthestraingaugepairsare alignedacrosstheroadwayormineopening(ietheboltaxialplanecontainingthe straingaugepairsisperpendiculartotheroadwayormineopeningaxis).

Thisisnecessarytoobtainmeasurementofthestraindifferenceatthegaugepairs duetolateralshearintheroadwayroof.



Readingandresultsanalysis

UsesuitableI.S.instrumentation,cablesandconnectorstotakereadingsofthe analysisstraingaugesatthespecifiedintervals.Analysetheresultsusingsuitable computersoftware,intermsofmeanstrainsandstraindifferences,loadprofiles andbendingmoments.



Appendix3Sonicextensometer

Introduction

Thesonicprobeextensometerisdesignedtomeasurethedistancebetweenpairs ofmagnetsupto10maparttoanaccuracyof0.02mm.

Theinstrumentconsistsofaflexibleprobewithatransducerheadattachedanda portablebatterypoweredreadoutunit.Theprobeisinsertedintoapredrilled hole,usuallyof43mmdiameter,containingupto20permanentmagnetswhich areanchoredtothestrata.Thismeasurementsystemisknownasthesonic extensometer(seeFigure4).

Installationprocedure

A verticalhole,atleast7mlong,isdrilledintothecentreoftheroofatthefaceof theheading.Aflexible,plastic,hollowtubeistheninsertedintheholeand anchoredinplace.Upto20permanentmagnetsarethen,inturn,placedaround thiscentralguidetubeandanchoredatpredeterminedintervalsalongthehole.

Readingsaretakenbyinsertingtheflexibleprobeinthecentralguidetubeand connectingtheprobetransducertothereadoutbox.Allmagnetdistancesare referredtothemagnetlocatedatthecollaroftheboreholeandthemagnet locationsaremeasuredinsequence.

Principleofoperation

Whenconnectedtothereadoutunit,theprobereceivesasmallcurrentpulse whichtravelsalongathinwalledmetaltubewithintheprobe.Ateachmagnet positiontheinteractionofthestaticfield(duetothemagnet)andthefield(dueto thecurrentpulse)producesatorsionaldeformationinthethinwalledtube.This deformationistransmitteddownthetubeasasonicpulseanddetectedbya torsionaltransducerlocatedattheendoftheprobe.Sonicpulsesfromeach magnetpositionarriveatthetransducerheadatdifferenttimes,dependingonhow fartheyhavetravelled.Thespeedofthemechanicallytransmitted,sonic,pulseis knownand,usingaveryaccuratetimer,thereadoutunitcalculatesanddisplays thepositionsofthemagnetswithhighresolution.

Results

Sonicextensometersoftwareisavailablewhichcanbeusedtoanalyseand presentthedatainavarietyofways,including:

totalroofmovementattheanchorpositionsatdifferenttimesorfaceadvance; strainbetweenanchorsatdifferenttimesorfaceadvance; totalmovementatindividualanchorpositionsplottedagainsttimeorface

advance.



Guide tube anchoredat top of hole

Typically43 mm

MagnetAnchor

Up to 20 magnetsanchored to strata

Reference magnetand anchor

Sonic extensometer probeinserted in the guide tube

To readout

At least 7 metres

Figure4Sonicextensometer



Appendix4Dualheighttelltale

Introduction

Dualheighttelltalesareavailableforuseinavarietyofholesizesfromnominal27mmdiametertonominal55mmdiameter.ThegeneralassemblyisshowninFigure5.

Installation

Drillhole,usingappropriatebitsize,totherequiredheight(2xboltheightor 4.8m,whicheverisgreater).

Insertreferencetubeandpushintight. Inserttopanchor,attachedtosmallestindicatorB,totopofhole.Checkfor

firmanchorage. Insertloweranchor,attachedtoIargerindicatorA,to0.3mbelowthebolted

height,eg2.1mfor2.4mbolt. PositionthetopofthegreenbandonindicatorAtobelevelwithbottomof

referencetube.Aligntoscale.Crimpferruleinposition. PositionthetopofthegreenbandonindicatorBtobelevelwithbottomof

indicatorA.Aligntoscale.Crimpferruleinposition. Recorddetails:positionofhole,dateandtime,anchorheights.

Readingmethods(seeFigure6)

1.Bycolour

Reportwholeandpartbandsvisible,forexample:

A:1/2green,yellow,red.

B:3/4yellow,red.

2.Byscale

Reportmeasurement,inmillimetres,liningupwithreferencemarkforeachanchor.

ReferenceforAisbottomofreferencetube.

ReferenceforBisbottomofindicatorA.

Scalehasmillimetredivisions,withcentimetremarks.Forexample:

A:12mm;

B:31mm.



Interpretation

MovementofArelativetothereferencetubeisequaltothestrataexpansion withintheboltedheight.

MovementofBrelativetoitsreference(bottomofA)isequaltothestrata expansionbetween thetopoftheboltandtheupperanchorposition.

ThetotalstrataexpansionisAplusB. Expansionofstrataabovethetopanchorisnotdetected.

'A' Anchor

'B' Anchor

'A'

'B'

10

20

30

40

50

60

70

10

20

30

40

50

60

70

yellow

yellow

Referencetube

green

red

green

red

Figure5Dualheighttelltalegeneralassembly



Action

See paragraphs54to60inthemaintextofthisdocument.

A

B

yellow

yellow

green

red

green

red

Readingbycolour

Readingbyscale

yellow

yellow

10

20

30

40

50

60

70

10

20

30

40

50

60

70

ReferencepointforA

ReferencepointforB

green

red

green

red

Figure6Rockboltdualheighttelltalereadingmethods



Appendix5Multiwireextensometers

Introduction

Themultiwireextensometerconsistsofa7mlong,verticalhole,usuallyof35mm diameter,drilledintothecentreoftheroofatthefaceoftheheading,containing fourseparatewires,eachanchoredatadifferentheight.Thewiresareterminated justbelowthebottomofthehole.Thesystemcanbereadmanuallybymeasuring thedistancefromareferencepointoneachwiretothemouthofthehole. Alternatively,aremotemonitoringsystemwithsuitabletransducersanddata transmissioncanbeemployed.

Principleofoperation

A diagramofthesystemisshowninFigure7.Thewiresareanchoredatdifferent heightsintheboreholeusingtwosimpleprongsprings.Thesearecheap,effective andeasilyinstalled.Therecommendedanchorageheightsofthespringsareas follows:

Minimum7m: Thehigherthetopspringisanchoredthemorelikelyitistobe anchoredinstableground.Thisisdesirableasthetopanchorprovidesthe referenceagainstwhichthemovementofalltheothersiscompared.

Boltlength+0.3m: Thisanchormeasuresroofdilationjustabovethebolted height.

Boltlength0.3m: Thisanchorisplacedattheboundarybetweenthebolted heightandtheroofabovetheboltedheight.Itisplacedbelowthetopofthe boltsasitispossibleforthetopsoftheboltstobewithdrawnfromthe overlyingstrataifroofdilationoccurswithinthetop0.3moftheboltedheight.

0.5m: Thisanchorisplacedbetweentheimmediateorlowerroof,whichcan bepronetospall,flakingandslabbing,andtherestoftheboltedheightwhich needstobefullystabilisedbytherockbolts.

Additionalanchorsmaybeplacedatotherheightsifrequired.Thiswouldbe appropriateif,forinstance,therewasanabruptchangeofrocktypewithinthe lengthofthehole.Theuseofmorethansixanchorsisnotrecommendedas thereisadangeroftanglingthewires.

Thepositionofeachanchorneedstobeaccuratelyrecorded.

Thewiresarebroughtthroughasuitablereferencepointplacedatthemouthofthe holeandareterminatedabout250mmbelowthereferencewithanelectrical connector.Thewireshavetobeuniquelylabelled.Numberedcollarsareusually usedforthispurpose.

Readingmethod

Placeresponsibilityforreadingthewireextensometerswithacompetentperson, asitrequirescare,accuracyandconsistency.Thatpersonalsoneedstobemade responsibleforrecordingthereadings,analysingthedataandprovidingtheresults tothemanagerofthemine,orarepresentative.

Clearlynumbereachextensometerandkeeparecordofitspositionandnumber.

Toreadanextensometer,hangaweight(suchasasafetylamp)fromeachwirein turnandmeasurethedistancebetweenthereferencepointandtheupperendof theelectricalconnector.Asteeltape,orruler,isadequatefortakingthereadings whichneedtoberecordedtothenearestmillimetre.Ensureeveryeffortismade forthesamepersontotakethereadingsusingthesametapetoreduceerrors. Recordboththedateandfacedistanceforeachsetofreadings.



Results

Theresultsmaybegraphedbyhand.However,suitablesoftwarepackagesare availablewhichcanbeusedtoanalyseandpresentthedatainavarietyofways including:

totalroofmovementattheanchorpositionsatdifferenttimesorfaceadvance; strainbetweenanchorsatdifferenttimesorfaceadvance; totalmovementatindividualanchorpositionsplottedagainsttimeorface

advance.

1 3 24

1

2

3

4Stable reference anchor

7 metres

Figure7Multiwireextensometer



Appendix6Exampleofscheduleofmeasurementzonesand measurementfrequencies

Location Zonenumber Measurementfrequency

Telltales Extensometers

WestParkgateA&BroadstoNo.5slit 1 W M

WestParkgateA&BroadsNo.5toNo.12slit 2 W M

WestParkgateA&BroadsNo.12toNo.15slit 3 W M

WestParkgateIntakeCroadQtoDT3 4 W M

WestParkgateIntakeEroadUtoSA4 5 M M

103sAccessA&Broads&DMReturn 6 M M

101sTailGateC&DroadstoNo.6slit 7 M M

101sTailGateC&DNo.6toNo.10slit 8 W M

101s TailGateC&DNo.10toNo.14slit 9 M M

101s TailGateC&DNo.14toNo.18slit 10 M M



* W = Weekly M = Monthly



Appendix7Inspectingofficialstelltalechecklist

COLLIERY:....... SHIFT:.........DATE:........

INSPECTION DISTRICT:........ NO.TELLTALESONDISTRICT:...................

TELLTALENUMBER ACOLOUR BCOLOUR SIGNY/N ACTION/COMMENT

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

PRINTNAME: SIGNATURE:.....................................

AlldefectsindicatedonthisformshallbeextractedandrecordedonyourDistrictInspectionReport.

ThisformshallbesubmittedtotheRegulation13.1(d)OfficewithyourDistrictInspectionReport.



Appendix8Training

Trainingcoursesforthoseinvolvedinrockboltingneedtoincludethefollowing aspects:

Managers

Provideanunderstandingoftheforcespresentintherockandthe redistributionoftheseasaconsequenceofminingoperations.

Illustratethedifferencesbetweenconventionalsupportandrockbolting. Explaintheactionofrockboltsinlimitingroofmovementandroadway

deformation. Highlighttheadverseeffectsofpoorinstallationstandards. Provideanappreciationofmonitoringtechniquesandtheinformationobtained,

togetherwithdetailsoftheinstallationandinspectionproceduresforthetelltale monitoringsystemandalsothesettingofactionlevelsandassociatedactions.

Giveguidanceontheconstructionandimplementationofthemanagers schemefortheroutinemonitoringofrockboltedroadways.

Instructontheinspectionofboltedroofandribsforsignsofexcessivebolt loadingordeterioration,andtheactiontobetakenifthesearediscovered.

Rockboltingcoordinator

Anintroductiontorockmechanicsprinciplesasappliedtorockboltingincluding suchtopicsasstress,thestrata,designofreinforcementsystems, undergroundengineering,consumablesandseveraldetailedcasehistoriesand includesitevisitswherepossible.

Managementofthemanagersschemefortheroutinemonitoringofrockbolted roadways.

Installation,replacementandreadingofallroutinemonitoringdevicesusedat theirmine.

Familiarisationanduseoftheappropriatecomputersoftware. Settingofappropriateroutinemonitoringactionlevelsforeachareaofthe

mine. Settingofappropriatecorrespondingremedialactionforactionlevelsforeach

areaofthemine. Determinationofappropriatemeasuringfrequenciesforroutinemonitoring

deviceswithinthemine. Followuponremedialactionstosecurestability. Formulationandupdatingofthescheduleofmeasurementzonesand

measuringfrequencyandrelatedmeasuringtimetables. Productionofofficialstelltalechecklists.

Officials

Anappreciationofbasicrockmechanicsasappliedinrockbolting. Allaspectsoftheminemonitoringsystem. Actionlevels. Action,dutiesandresponsibilities. Remedialmeasures. Followupactions. Communicationlinks. Allaspectsofthetelltalechecklistsystemattheirmine. Appreciationoftelltales. Thecorrectinstallationoftelltales. Thereplacementoftelltales. Theidentificationoftelltales. Readingoftelltalesandappropriateactionlevelsandtheassociatedactionto

betaken.



Instructionontheinspectionofboltedroofandribsforsignsofexcessivebolt loadingordeteriorationandtheactionstobetakenifthesearediscovered.

Appropriatetypesofextrasupporttosecuretheroofinadverseconditions.

Operators

Theactionofrockboltsandtypicalrockboltpatterns,highlightingthe importanceofgoodinstallationpractice.

Correctinstallationofrockboltsincludingadequate,practicalonsitetraining. Thesequenceofoperationsandthetimeatwhichrockboltingiscarriedout. Maintenanceoftherockboltingequipment(drillingmachinesetc)toensurethat

performanceismaintainedatdesignedlevels.Particularattentionneedstobe directedtoensureprovisionofasufficientsupplyofeitherhydraulicfluid,or compressedair,(asappropriate)toallowthedrillingequipmenttooperate withindesignparameters.

Provisionofthecorrectlengthofdrillrodinanundamagedconditionand arrangementstoensurethatthecorrectdepthofholeisdrilled(forexample premarkingthedrillrod).

Thetype,numberofcapsulesandsequenceofinsertionofresinintothehole, togetherwiththeimportanceoftherecommendedmixandwaittimes.

Anappreciationofthemanagersschemeforrockboltmonitoring,the informationindicatedbymeansofthetelltalemonitoringsystemandaction, whereappropriate.

Aninstructionthatoperators,intheeventofdifficultyintheapplicationof rockboltingandmonitoring,needtobringthosematterstotheattentionof thosehavingstatutoryresponsibilityforthesupervisionofoperations.

Wherecableboltsaretobeinstalledasadditionalsupport,operativesshould alsoreceivetrainingin: correctcableboltinstallationproceduresincludingonsitetraining; approvedconsumables; personalprotectiveequipment.



Appendix9Standuptimeforextendedcutouts:Assessing extendedcutoutdistance

Whereadistancegreaterthanthatrequiredtosetthenextrockboltsupportiscut, thepossibleeffectofthisextendedcutoutonroofstabilityneedstobeassessed. Thisinvestigationoughttotaketheformofaprogressiveincreaseincutout distancetotheplannedvaluewithassessmentateachstageasfollows:

Assessexistinggeotechnicalinformationtoconfirmsitesuitabilityforan extendedcuttrialintermsofstrataconditions,totalroofmovement,rateof movementandpositionofroofstrainzones.

Excavatetheproposedincreasedcutoutdistanceatthetrialsitewithout exposingthedrivertounsupportedroof.

Donotinstallrockbolts. Installsufficienttemporarystandingsupporttoallowaremotereadingroof

extensometertobeinstalledhalfwayalongtheexcavatedsection. Removethetemporarysupportifappropriate. Monitorroofdilationviatheremotereadingextensometerforthemaximum

likelydelaytimebeforeboltsareinstalled(48hoursisconsideredtobea minimum).

Themeasuredpatternofroofdeformationshouldbecomparabletoprevious siteresults.Ifthereisnosignificantroofdeformationinthisperiod,anextended trialshouldtakeplaceasfollows:

(a)assesstheoveralleffectofthecutoutdistanceonroadwaystabilityby monitoring,eginstallationofadditionaltelltalesandextensometers.The assessmentneedstoincludethepossibilityofafalloverridingsupportedroof;

(b) iftheresultsoftheassessmentaresatisfactory,then,instages,increasethe cutoutdistancetotheproposedvalue.Eachstageneedstobesubjecttothe monitoringandassessmentdescribedin(a).

Theextendedcutoutdistanceneedstobeconsideredamaximumandvariedto suittheprevailinggeotechnicalconditions.



Appendix10Liftingandsuspensionofequipmentin rockboltedroadways

1 Rockboltsinstalledforroofsupportpurposesshouldonlybeused(with suitableliftingshackles)forliftingorsuspendinglightloadsofuptoamaximumof 1 tonneonanindividualbolt,providedthattheloadonanyrowofboltsdoesnot exceed1tonneintotal.

2 Anyboltusedfortheliftingorsuspensionofequipmentotherthanasabove shouldbeananchorbolt.

3 Anchorboltsandtheirassociatedliftingshacklesshouldbesuitableforthe purposewheninstalledincompliancewithinstructionsprovidedbythesupplier. Theyshouldbereadilyidentifiableasanchorboltsbothbeforeandafterinstallation.

4 Themanagerofthemineshouldmakeruleswhichcovertheliftingor suspensionofequipmentinroadwayssupportedbyrockboltsandwhichtakeinto account:

thespecificationoftheboltsandliftingshackles; theweightoftheequipment; anyinducedloadthatmayactontheboltsorsuspensionequipment.(The

dynamicloadfromtheinflexionpointofatensionedconveyorisoneexample of aninducedload);

thenumberandlayoutoftheboltstoensurestabilityoftheequipment; themanufacturersinstructionsfortheinstallationanduseofthebolts; theintegrityoftheboltandtheeffectsofcorrosion; theadditionalimposedloadingonthestrata;and theneedforadditionalroofsupport.

5 Beforeanchorboltsareinstalledthecoordinatororacompetentperson appointedbythemanagershouldexamineandtest,ifnecessary,theroofstrata where theboltsaretobeinstalledtoensurethatthecurrentsupportisadequate andthestrataisinasuitablecondition.Thisinspectionshouldincludeinspectionof nearbymonitoringdevices.

6 Followingtheinstallationoftheanchorboltsandpriortosubsequentuse thereof,thecoordinatororacompetentpersonappointedbythemanagershould examinetheinstallationoftheanchorbolts,supplementedbytestsifnecessary,to confirmthattheyhavebeeninstalledinaccordancewiththemanagersrulesand theroofsupporthasnotdeterioratedsincethepreviousexamination.

7 Whereanchorboltsareinstalledforthepurposesofliftingorsuspensionof equipment,monitoringofthestratashouldbeincorporatedinthemanagersrules. Whereexistingmonitoringdevicesareremotefromthesiteandwouldnotbe representativeoftheimmediateareawheretheliftingoperationsaretotakeplace, dedicatedmonitoringshouldbeinstalledpriortolifting.Monitoringdevicesshould bereadbeforeandafterallliftingoperationsandshouldbemonitoredatregular intervalswhenliftingistakingplace.



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