Excavations

OregonOSHA

Safe practices for small business owners and contractors

How to dig your own grave

No protective system

Spoils too close

No means for entering or exiting

No hard hat

Excavator bucket over worker

www.orosha.org

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About this document Excavations – Safe practices for small business owners and contractors is an Oregon OSHA Standards and Technical Resources publication.

Thanks to the following individuals for advice and technical assistance.• CraigHamelund,OregonOSHA• DiannaGray,OregonOSHA• GeorgeVorhauer,OregonOSHA• JerryMothersbaugh,OregonOSHA• MikeRiffe,OregonOSHA• RockyShampang,OregonOSHA• RonHaverkost,OregonOSHA• TimMarcum,OregonOSHA

Special thanks to Mike Parnell,president,WireRope&Rigging Consultants,foradviceonsaferiggingpractices.

Thankstothefollowingindividualsforcraftingthefinaldocument:• Layoutanddesign:PatriciaYoung,OregonOSHA• Editingandproofing:MarkPeterson,DCBSCommunications

WewantyoutounderstandwhatyoureadThisguidecomeswithaplain-languageguarantee!Letusknowifyou’renotsatisfied.ContactEllisBraschatellis.k.brasch@state.or.us orcall503-947-7399.

Piracynotice.Reprinting,excerpting,orplagiarizinganypartof this publication is fine with us!PleaseinformOregonOSHAofyour intensionasacourtesy.

ContentsIntroduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Excavations and trenches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Plan before you dig . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

The role of the competent person . . . . . . . . . . . . . . . . . . . . . . . . . 9

How cave-ins occur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

How soil is tested . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Protective systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Getting in and out of an excavation . . . . . . . . . . . . . . . . . . . . . . . 18

Materials and mobile equipment . . . . . . . . . . . . . . . . . . . . . . . . . 19

Hazardous atmospheres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Water accumulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Working with hydraulic excavators and backhoe loaders . . . . . . 22

Working near high-voltage lines . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Stability and adjacent structures . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Excavation requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Safe practices checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Important terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Oregon OSHA Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

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IntroductionAcave-incantrapyouwithinsecondsandkillyouwithinminutes.

Twocubicyardsofsoilweighabout6,000pounds.Ifyou’reburied,you’llsuffocateinlessthanthreeminutes.Evenifyousurvive,theweightofthesoilislikelytocauseseriousinternalinjuries.

Butcave-insaren’ttheonlydangersinexcavationwork.Lackof oxygen,toxicfumes,explosivegases,andburiedpowerlinesarealsohazards.Unfortunately,manycontractorswhodoexcavationwork stillthinkthatit’stooexpensiveortakestoomuchtimetoprovide appropriate safeguards.

Twocubicyardsofsoilweighabout6,000pounds!

3,000 pounds

3,000 pounds

How much does soil weigh?

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Excavations and TrenchesDigaholeinthegroundandyou’vemadeanexcavation.Excavationscanbeanysize:wide,narrow,deep,orshallow.

A trenchisanarrowexcavation,notmorethan15feetwideatthebottom.Ifyouinstallformsorotherstructuresinanexcavationthatreduceitswidthtolessthan15feet,measuredatthebottom,theexcavationisalsoconsideredatrench.

Ifyouworkinanexcavationthat’sfivefeetdeep(ordeeper)youmustbeprotectedfromacave-in.

Ifacompetent persondeterminesthatthere’sapotentialforanexcavationtocave-in,youmustbeprotectedregardlessofitsdepth.

Whatisanexcavation?Anexcavationisaman-madecut,cavity,ordepressionintheearth’ssurface.

Excavation

Open-faced excavation

Excavation cut into slope

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Trench

• Deeperthanwide• Nomorethan 15feetwideat thebottom

Whatisatrench?Atrenchisdeeperthanitiswide–andnotmorethan15feetwideatthebottom.

• Typicaltrench

• Trenchcreatedbyformwork

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Plan before you digPlanningreducesthechancethatsomethingwillgowrongwhenyoustartajob.Considerthefollowingbeforeyoustartexcavating:

• Debrisneartheexcavationsitethatcouldcreateahazard

• Howemployeeswillgetinandoutoftheexcavation

• Howtoprotectpeoplefromfallingintotheexcavation

• Howtorespondtoemergencies

• Locationofoverheadpowerlinesandundergroundutilitylines (Call 811 from anywhere in Oregon for help in locating underground utility lines)

• Possibilityofatmospherichazardsintheexcavation

• Possibilityofwaterintheexcavation

• Stabilityofsoilattheexcavationsite

• Stabilityofstructuresadjacenttotheexcavationsite

• Vehiclesandothermobileequipmentthatwilloperatenear theexcavation

• Weatherconditions

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The role of the competent personAdesignatedcompetentpersonwhohastraininginsoilanalysis, protectivesystems,andOregonOSHA’sDivision 3, Subdivision P, Excavationrequirementsmustbeonsitetoclassifythesoil,selectaprotectivesystem,overseeinstallation,andinspectthesystemafterinstallation.

Iftherearenoexistinghazardsthecompetentpersoncanleavetheexcavationsiteforashorttime,butmustbepresentwhenaprotec-tivesystemismoved.Soilconditionscouldchangeornewhazardsmayarisethatrequirethecompetentperson’sjudgment.

Thecompetentpersonmustbeknowledgeableaboutthetypeofsoilexcavatedandtheprotectivesystemusedandmustinspectthemdailyforsignsofinstability,damage,orotherhazards;thecompetentpersonmustapproveanychanges.Inspectionsarealsonecessaryafterheavyrainoractivitiessuchasblastingthatmayincreasetheriskofcave-in.

Thecompetentpersonmusthaveauthoritytoimmediatelycorrectthehazardsandtoorderemployeestoleavetheexcavationuntilthehaz-ardshavebeencorrected.Anemployeewhoistrainedandcanidentifyexcavationhazardsbutdoesn’thavetheauthoritytocorrectthemisnotacompetentperson.

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How cave-ins occur Undisturbedsoilstaysinplacebecauseopposinghorizontalandverti-calforcesareevenlybalanced.Whenyoucreateanexcavation,youremovethesoilthatprovideshorizontalsupport.Soilwilleventuallymovedownwardintotheexcavation.Thelongertheface(asideoftheexcavation)remainsunsupported,themorelikelyitistocavein.

BulgingSliding Toppling

Howdocave-insoccur?Whenyoucreateanexcavation,youremovethesoilthatprovideshorizontalsupport.

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Soilandstability

Somesoilsaremorestablethanothers.Thetypeofsoilisoneofthefactorsthatdeterminethechancethatanexcavationwillcavein.TherearethreebasicsoiltypesthatyoumayencounterinOregon:

• TypeA–verystable.Clayisanexample.

• TypeB–lessstablethantypeAsoil.Crushedrock,silt,andsoilsthatcontainanequalmixtureofsandandsiltareexamples.

• TypeC–lessstablethantypeBsoil.Gravelandsandareexamples.Soilhasotherqualitiesthataffectitsstability.Theseincludegranularity, saturation, cohesiveness, and unconfined compressive strength.

• Granularityreferstothesizeofthesoilgrains;thelargerthegrains,thelessstable the soil.

• Saturationmeanshowmuchwatersoilwillabsorb.

• Cohesivenessmeanshowwellsoilholdstogether;clayisacohesivesoil.

• Unconfinedcompressivestrengthisdeterminedbyatestthatshowshowmuchpressureittakestocollapseasoilsample.Forexample,typeAsoilmusthaveanunconfinedcompressivestrengthofatleast1.5tonspersquarefoot.

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How soil is testedAcompetentpersonmustconductvisual and manual soil tests before anyoneentersanexcavation.Visualandmanualtestsareacriticalpartofdeterminingthetypeofprotectivesystemthatwillbeused.

Visual tests

Visualtestinginvolveslookingatthesoilandtheareaaroundtheexcavationsiteforsignsofinstability.Thecompetentpersonmightdovisualtestssuchasthefollowing:

• Observethesoilasitisexcavated.Soilthatremainsinlargeclumpswhenexcavatedmaybecohesive.Soilthatbreaksupeasilyisgranular.

• Examinetheparticlesizesofexcavatedsoiltodeterminehowtheyholdtogether.

• Lookforcracksorfissuresinthefacesoftheexcavation.

• Lookforlayersofdifferentsoiltypesandtheangleofthelayersinthefaceoftheexcavationthatmayindicateinstability.

• Lookforwaterseepingfromthesidesoftheexcavation.

• Lookforsignsofpreviouslydisturbedsoilfromotherconstructionorexcavationwork.

• Considervibrationfromconstructionactivityorhighwaytrafficthatmayaffectthestabilityoftheexcavation.

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Manual tests

Manualtestinginvolvesevaluatingasampleofsoilfromtheexcavationtodeterminequalitiessuchascohesiveness,granularity,andunconfinedcompressivestrength.Soilcanbetestedeitheronsiteoroffsitebutshouldbetestedassoonaspossibletopreserveitsnaturalmoisture.

Examples of manual tests:

Plasticitytest.Shapeasampleofmoistsoilintoaballandtrytorollitintothreadsabout1/8-inchindiameter.Cohesivesoilwillrollinto1/8-inchthreadswithoutcrumbling.

Drystrengthtest. Holdadrysoilsampleinyourhand.Ifthesoilisdryandcrumblesonitsownorwithmoderatepressureintoindividualgrainsorfinepowder,it’sgranular.Ifthesoilbreaksintoclumpsthatarehardtobreakintosmallerclumps,itmaybeclaycombinedwithgravel,sand,orsilt.

Thumbpenetrationtest. Thistestroughlyestimatestheunconfinedcompressivestrengthofasample.Pressyourthumbintothesoilsample.IfthesampleresistshardpressureitmaybetypeAsoil.Ifit’seasytopenetrate,thesamplemaybetypeC.

Pocket penetrometers offermoreaccurateestimatesofunconfinedcompressivestrength.Theseinstrumentsestimatetheunconfinedcompressivestrengthofsaturatedcohesivesoils.Whenpushedintothesample,anindicatorsleevedisplaysanestimateintonspersquarefootorkilogramspersquarecentimeter.

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Protective systemsThebasicmethodsforprotectionfromcave-insaresloping, benching, shoring,andshielding.Themethodyoushouldusedependsonfactorssuchassoiltypeandwatercontent,excavationdepthandwidth,thenatureofthework,andnearbyactivitiesthatcouldincreasetheriskofacave-in.Thecompetentpersonhastheresponsibilityforconsideringthesefactorsandfordeterminingtheappropriateprotectivesystem.

A registered professional engineermustdesignprotectivesystemsforallexcavationsthataremorethan20feetdeep.

Sloping and benching

Slopingandbenchingprovideprotectionbyremovingmaterialfromthefaceofanexcavationatanangletoitsfloor;ingeneral,theflattertheangle,thegreatertheprotection.Benchesarecutsintheslopethatgiveitastair-stepappearance.Therearetwotypesofbenches:simpleandmultiple.

Rain,vibration,andpressurefromheavyequipmentcanmakesoilun-stableandincreasetheriskofacave-in.Slopedorbenchedexcavationsthatshowsignsofcracks,bulges,orclumpsofsoilthatfallawayfromthefacesaredangerousandmustbeinspectedbyacompetentperson.Youmustimmediatelygetoutoftheexcavationandstayawayuntilthecompetentpersondeterminesitissafetoenter.

Aregisteredprofessionalengineermustdeterminetheangleofslopesinexcavationsthataredeeperthan20feet.

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WhatdobenchedslopeslooklikeintypeA,typeB,andtypeCsoil?

• TypeAsoil:simpleandmultiplebenches

Simple Bench Excavation Multiple Bench Excavation

Simple Bench Excavation Multiple Bench Excavation

• TypeBsoil:simpleandmultiplebenches

• TypeCsoil:simpleandmultiplebenches

BenchingintypeCsoilrequiresaregisteredprofessionalengineer.

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Shoring and shielding

Shoringandshieldingsystemscanpreventcave-insinexcavationswithorwithoutslopedorbenchedfaces.Thesafestwaytoinstallandremovethemisfromoutsidetheexcavation.

Shoresareverticalorhorizontalsupportsthatpreventthefacesofanexcavationfromcollapsing.Verticalshoresarecalleduprights.They’reeasytoinstall,relativelyinexpensive,andoftenusedinstablesoilorinshallowexcavationsthathaveparallelfaces.Verticalshoresmustbesizedfortheexcavation’sdimensionsandsoiltype.

Horizontalshoresarecalled walers.Walersareoftenusedwhenun-stablesoilmakesslopingorbenchingimpracticalandwhensheetingisnecessarytopreventsoilfromslidingintotheexcavation.

Shieldsprovideemployeesasafeworkareabyprotectingthemfromcollapsingsoil.Shieldsdon’tpreventcave-insbut“shield”workersifafacedoescollapse.Theyareusuallyplacedintheexcavationbyheavyequipment.

Shoringandshieldingsystemsareavailablefrommanufacturersinavarietyofdimensions,usuallyaluminumorsteel,ortheycanbecustom-builtfromtabulated data approvedbyaregisteredprofessionalengineer.Manufacturerswillalsoprovidetabulateddatawiththeirsystemsthatincludesengineeringspecifications,depthratings,specialinstructions,andsystemlimitations.Onlybycarefullystudyingandunderstandingthemanufacturer’stabulateddatacanthecompetentpersonchoosethecorrectprotectivesystem.

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Whatdoshoresandshieldslooklike?

Vertical shore

Photo credit: Speed Shore Corp.Photo credit: Speed Shore Corp.

Horizontal shore

Photo credit: Speed Shore Corp.

Trench shield

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Getting in and out of an excavationAnexcavationthathasadepthoffourfeetormoremusthavea meansforenteringandexiting—suchasastairway,ladder,or ramp—within25feetofemployees;theirsafetymaydependon howquicklytheycanclimbout.

Structuralrampsthatareusedtoenterandexittheexcavation musthavenonslipsurfacesandbedesignedbyacompetentperson.Acompetentpersonmustalsoevaluaterampsmadefromsoilthatareusedtoenterandexitanexcavation.

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Materials and mobile equipmentExcavatedsoil,calledspoils,piledtooclosetotheedgeofanexcavationcancauseacave-in.Socanheavyequipment.Keepspoilsandheavyequipmentatleasttwofeetfromtheedge;whenpossible,useverticalshoresorshieldsthatextendabovethetopoftheexcavationtorestrainspoils.Spoilsandheavyequipmentthatexertanexcessiveloadongroundadjacenttotheexcavationcouldcauseacave-in.

Spoilsandheavyequipmentthatexertanexcessiveloadongroundadjacenttoanexcavationcouldcauseacave-in.

Whenarespoilshazardous?

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Hazardous atmospheresHazardousatmospherescanoccurinexcavationsnearlandfills,sitescontaminatedbyleakinggaslinesorstoragetanks,insewers,andinotherconfinedspaces.Iftheseconditionsarepossible,acompetentpersonmusttestforoxygendeficiency(oxygenlevelslessthan19.5percent)andhazardousatmospheresbeforeyoucanenter.

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Water accumulationWatermakessoilunstable.Youcan’tenteranexcavationwhenwaterhasbuiltupunlessyouareprotectedfromtheunstablesoil.Protectionincludesspecializedsupportsystemsandwater-removalequipment.Acompetentpersonmustinspecttheexcavationandmonitormethodsusedtocontrolwateraccumulation.

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Working with hydraulic excavators and backhoe loadersYoucandiganexcavationwithahandshoveloranexcavator.Useahandshovelimproperlyandyouriskblisters.Useanexcavatorimprop-erlyandyouriskalife.Toomanyworkersarehurtbecausetheydon’tfollowsafepracticeswhentheyusehydraulicexcavatorsandbackhoeloaders.Mostaccidentshappenforthreereasons:

• Enteringtheexcavator’sswingarea

• Usingquick-couplingdevicesimproperly

• Usingunsaferiggingmethodstodragatrenchshield

Entering the excavator’s swing area

Beawareoftheexcavator’sswingareaandblindspots.Alwaysmaintainatleastthreefeetofunimpairedclearancebetweentheexcavator’sro-tatingsuperstructureandadjacentobjects.Keepothersoutsidetheareabymarkingitwithrope,tape,orasimilarbarrier,ifnecessary.

• PostwarningsignsthatsayDANGER–STAYCLEAR on allsidesoftheexcavator.

• Don’tallowanyonetostandunderasuspendedloadortheboom,arm,orbucket.

• Keepthebucketasclosetothegroundaspossiblewhen workers are attaching loads.

• Lowertheboomtoasafepositionwiththebucketonthegroundandturnofftheexcavatorbeforegettingoff.

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WheredoIpostthewarningsigns?PostwarningsignsthatsayDANGER–STAYCLEARonallsidesoftheexcavator [fromDivision 3, Subdivision O,437-003-0090(1)]

Don’tallowanyonetostandundertheboom,arm,orbucket!

Photo credit: Robert I. Carr, Ph.D., P.E.

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Usingquick-couplingdevicesimproperly

Aftermarket“quick-coupling”devicesmakeiteasytochangebucketsorreplaceotherattachments.However,anumberofworkershavebeenkilledwhenthecouplingdeviceshavenotbeenlockedproperlyandthebucketshavedetached.Manufacturersofquickcouplersrecognizedthehazardandnewerdeviceshavelocksthatpreventbucketsfromdetach-ingunintentionally,butnotallusersmaybeawareoftheproblem.Retrofitlockingpinsareavailableforolderequipment.

• Followthemanufacturer’sinstructionsforusingpositivelocksonquick-disconnectequipment.

• Securelylatchattachmentssuchasquick-disconnectbucketsbeforebeginning work.

• Makefrequentvisualinspectionsofquick-disconnectsystems—especiallyafterchangingattachments.

Using unsafe rigging methods to drag a trench shield

Usinganexcavatortodragashieldthroughatrenchcanputtremen-dousforcesonriggingcomponents.Forexample,theforcerequiredtodraga10,000-poundtrenchshieldthroughanarrowtrenchwillincreasedramaticallywithresistancefromthetrenchwallsorfromplowingofthefrontoftheshield.Knowthesling’sratedcapacitiesandneverexceedthem.Thewhiplasheffectofabrokenorimproperlyriggedslingcankillanyoneinitspath.

• Followtheinstructionsintheoperator’smanualwhenusinganexcavatortoliftormoveanobject.

• “Liftanddrag”tomoveatrenchshieldhorizontallyinatrench;avoid“plowing”withthefrontoftheshield.Plowingsignificantlyincreases the tension on the slings.

• Somemanufacturersoftrenchshieldswarnworkerstostayoutofthe“box”whileitisbeingmoved.Alwayscheckthemanufacturers’requirements.

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• Neverusedamagedchainsorfrayedcables,slings,straps,orropes.

• Useanappropriateliftingshackleforattachingcablesorslings.

• Neverstandinlinewith,ornextto,aslingthatisundertension.

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Working near high-voltage linesBeforeyoudoanyworkwithin10feetofahigh-voltagepowerline,notifytheutilitythatcontrolsthelineatleasttwobusinessdaysbeforeyoubegin.Ifyoudon’tknowwhocontrolstheline,anyutilitycan helpyou.

You’llneedtotelltheutilitythelocation,whatworkyouneedtodo,andwhenyouneedtodoit.

Theutilitywillhelpyouwithtaskssuchasthefollowingtoensurethatyoudotheworksafely:

• Coordinateworkschedules

• Identifytemporarymechanicalbarriersthatprevent contact with the lines

• De-energizeandgroundthelines

• Temporarilyraiseormovethelines

What happens if you don’t notify the utility?

You’reresponsibleforalldamagesandcoststhatresultfromanelectri-calaccident.There’salsoapenaltyofupto$70,000foreachoffenseinadditiontothecostofinjuriesandrepairs.

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Stability and adjacent structuresMakesurethatstructures,roadways,andsidewalksadjacenttotheexcavationareadequatelysupported.

• Useanappropriatesupportsystem–suchasshoringorbracing– iftheexcavationcouldaffectthestabilityofnearbybuildings,side-walks,androads.

• Don’texcavatebelowthebaseorfootingofanyfoundationthatmightendangeremployeesunlessyoudooneofthefollowing:

• Useasupportsystemthatprotectsemployeesandkeepsthestructure stable.

• Ensurethattheexcavationisinstablerock.

• Havearegisteredprofessionalengineerdeterminethatthestructurewillnotbeaffectedbytheexcavationwork.

• Havearegisteredprofessionalengineerdeterminethatthe excavationworkwillnotendangeremployees.

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Excavation requirementsOregonOSHA’sDivision 3, Subdivision P, Excavationrequirementsapplytoallopenexcavations.

• 1926.650—Scope,application,anddefinitions

• 1926.651—Specificexcavationrequirements

• 437-003-0096—Undergroundinstallations

• 1926.652—Requirementsforprotectivesystems

• AppendixA—Soilclassification

• AppendixB—Slopingandbenching

• AppendixC—Timbershoringfortrenches

• AppendixD—Aluminumhydraulicshoringfortrenches

• AppendixE—Alternativestotimbershoring

• AppendixF—Selectionofprotectivesystems

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1. Adesignatedcompetentpersonattheexcavationsiteunderstandsvisualandmanualtestmethods,useofprotectivesystems,thehazardsofexcavationwork,andtherequirementsofOregonOSHA’sexcavationstandards.

2. Adesignatedcompetentpersoninspectstheexcavation,adjacentareas,andprotectivesystemsdailybeforeworkbegins,asnecessarythroughouttheshift,andafterrainorotherconditionsthatcouldincreasetheriskofahazard.

3. Adesignatedcompetentpersonhasauthoritytoimmediatelycorrecthazardsandtoorderemployeestoleavetheexcavationuntilthehazardshavebeencorrected.

4. Sewer,telephone,fuel,electric,orwaterlinesnearthesitehavebeenlocatedandclearlymarked.ContacttheOregonUtilityNotificationCenterforhelpinlocatingundergroundutilitylines–call811fromanywhereinOregon.

5. Hardhatsarerequiredwheneverthereareoverheadhazards.

6. Debrisandotherunnecessarymaterialhavebeenclearedfromthesite.

Safe practices checklist Allyouranswersshouldbe“Yes!” Yes No

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7. Employeeswhoareexposedtovehicletrafficareprovidedwithandwearhigh-visibilitygarments.

8. Excavationsatremotesiteshaveappropriatewarningbarriers.

9. Employeesareprotectedfromlooserockorsoilthatcouldfallintotheexcavation.

10. Employeesareprohibitedfromworkingorstandingundersuspended loads.

11. Employeesarerequiredtostandawayfromvehiclesthatare being loaded or unloaded.

12. Employeesareprohibitedfromworkingonthefacesofslopedorbenchedexcavationswhenotheremployeesarebelowthem.

13. Mobileequipmentoperatorshaveaneffectivewayofknowingwhentheyaretooclosetotheedgeofanexcavation.Examplesincludebarricades,handormechanicalsignals,stoplogs,orgradingawayfromtheexcavation.

14. Spoils,equipment,andtoolsareatleasttwofeetfromtheedgeoftheexcavation.

15. Walkwaysthatcrossoverexcavationsmorethatsixfeetdeep have standard guard rails and toe boards.

Yes No

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16. Undergroundinstallationsareprotected,supported,orremovedwhentheexcavationisopen.

17. Excavationsthathaveadepthoffourfeetormorehaveladdersorothermeansofsafeaccesswithin25feetofemployees.

18. Laddersaresecuredandextendthreefeetaboveedgeoftheexcavation.

19. Adesignatedcompetentpersondesignsthestructuralrampsthatemployeesusetoenterandexittheexcavation.

20. Structuralrampshavenonslipsurfaces.

21. Employeesareprohibitedfromenteringanexcavationthatshowssignsofwateraccumulationunlesstheyareprotectedfromtheriskofacave-in.

22. Acompetentpersonmonitorsthemethodsusedtocontrolwaterfromaccumulatinginanexcavation.

23. Surfacewaterorrunoffisdivertedawayfromtheexcavation.

24. Theatmosphereinanexcavationistestedwhenthepossibilityofahazardousatmosphereexists.

25. Employeesareprotectedfromhazardousatmospheresoratmospherescontaininglessthan19.5percentoxygen.

Yes No

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26. Emergencyrescueequipmentisavailablewhenhazardousatmospherescouldexistinanexcavation.

27. Employeeswhoworkinexcavationsaretrainedtouseappropriatepersonalprotectiveequipment.

28. Adesignatedcompetentpersonhasclassifiedsoilattheexcavationsitewithatleastonemanualtestandone visual test.

29. Materialsandequipmentusedforprotectivesystemsattheexcavationsitearechosenbaseduponsoilanalysis,excavationdepth,andexpectedloads.

30. Materialsandequipmentusedforprotectivesystemsareinspectedregularlyandingoodcondition.

31. Damagedequipmentisremovedfromserviceimmediately.

32. Protectivesystemsareinstalledwithoutexposingemployeestotheriskofcave-ins.

33. Structures,roadways,andsidewalksadjacenttotheexcavationareadequatelysupported.

34. Excavationsarebackfilledwhenprotectivesystemsareremoved.

Yes No

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35. Appropriatesloping,shoring,orshieldingprotectsemployeeswhoworkinexcavationsfiveormorefeetdeep.

36. Adesignatedcompetentpersondeterminesthetypeofshieldusedatasitebyconsideringfactorssuchasthenatureofthework,excavationdimensions,soilcharacteristics,andequipmentusedtolowerorpositionthe shield.

37. Employeesinexcavationsmorethan20feetdeepareprotectedbyasystemdesignedbyaregisteredprofessional engineer.

38. Shieldsareinstalledsothattheydonotmovelaterally.

39. Employeesarenotallowedinshieldsthataremovedvertically.

Yes No

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Important termsAdjacent Theareawithinahorizontaldistancefromtheedgeofavertical-sided

excavationequaltothedepthoftheexcavation.

Aluminumhydraulicshoring Apre-engineeredsystemofaluminumhydrauliccylinders(crossbraces)andverticalrails(uprights)orhorizontalrails(walers).Designedtosupportthefacesofanexcavation.

Benching Amethodofslopingthesidesofanexcavationbyformingaseriesofsteps.

Cave-in Theseparationofamassofsoilorrockfromthefaceofanexcavationintoanexcavation.

Competent person Apersoncapableofidentifyingexistingandpredictablehazardsinthesurroundingsorworkingconditionsandwhohasauthorizationtotakepromptcorrectivemeasurestoeliminatethehazards.

Cross brace Horizontalmemberofashoringsysteminstalledperpendiculartothesidesofanexcavation,theendofwhichbearsagainstuprightsorwales.

Excavation Aman-madecut,cavity,ordepressionintheearth’ssurface.

Face Thesideofanexcavation.

Hazardousatmosphere Anatmospherethatcouldcauseaninjuryorillness.Examples:explosive,flammable,poisonous,corrosive,oxidizing,irritating,oxygendeficient,ortoxic.

Previouslydisturbedsoil Soilthathasbeendisturbedfromexcavationworkorotherdigging.SoilcannotbeclassifiedtypeAifithasbeenpreviouslydisturbed.Usevisualteststoidentifypreviouslydisturbedsoil.

Protectivesystem Asystemdesignedtoprotectworkersinexcavations.Slopingandbenching,shores,andshieldsareexamplesofprotectivesystems.

Ramp Aninclinedwalkingorworkingsurfaceconstructedfromearthorfromstructuralmaterialssuchassteelorwood.

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Registeredprofessionalengineer A professional engineer registered in the state where the work is performed.Aprofessionalengineerregisteredinanystatecanapprovedesignsformanufacturedprotectivesystemsortabulateddatausedininterstatecommerce.

Sheeting Componentofashoringsystemthatpreventssoilfromslidingintoanexcavation.

Shield Astructureabletowithstandforcescausedbyacave-in.Shieldscanbemanufacturedorcustom-builtinaccordancewith1926.652(c)(2)-(c)(4).Shieldsarealsocalledtrenchboxesandtrenchshields.

Shore Astructurethatsupportsthesidesofanexcavationandpreventscave-ins.

Sloping Amethodofincliningthefaceofanexcavationtominimizetheriskofacave-in.Themaximumallowableslopevarieswithsoiltype,environment,andworkdoneattheexcavationsite.

Soil Weatheredrock,gravel,sand,orcombinationsofclay,silt,andloam.

Stable rock Naturalsolidmineralmaterialthatcanbeexcavatedwithverticalsidesandwillremainintactwhileexposed.

Structural ramp Arampmadeofsteelorwood,usuallyforvehicleaccess.Rampsmadefromsoilorrocksarenotconsideredstructuralramps.

Supportsystem Asystemthatsupportsanadjacentstructure,undergroundinstallation,orthefaceofanexcavation.

Surcharge Aloadexertedongroundadjacenttoanexcavation.

Tabulated data Tablesandcharts,approvedbyaregisteredprofessionalengineer,usedtodesignandconstructaprotectivesystem.Atleastonecopyofthedataandthenameoftheengineerwhoapproveditmustbekeptatthesitewhilethesystemisconstructed.

Trench Anexcavationthatislongerthanwide.Ingeneral,thedepthisgreaterthanthewidthbutthewidthmeasuredatthebottomofthetrenchisnotgreaterthan15feet.

Upright Theverticalmemberofashoringsystem.

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ServicesOregonOSHAoffersawidevarietyofsafetyandhealthservicestoemployersandemployees:

Portland 1750 NW Naito Parkway, Ste. 112 Portland, OR 97209-2533 503-229-5910 Consultation: 503-229-6193

Salem 1340 Tandem Ave. NE, Ste. 160 Salem, OR 97303 503-378-3274 Consultation: 503-373-7819

Eugene 1140 Willagillespie, Ste. 42 Eugene, OR 97401-2101 541-686-7562 Consultation: 541-686-7913

Bend Red Oaks Square 1230 NE Third St., Ste. A-115 Bend, OR 97701-4374 541-388-6066 Consultation: 541-388-6068

Medford 1840 Barnett Road, Ste. D Medford, OR 97504-8250 541-776-6030 Consultation: 541-776-6016

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Formoreinformation,calltheOregonOSHAofficenearestyou.

SalemCentralOffice 350 Winter St. NE, Rm. 430Salem, OR 97301-3882Phone: 503-378-3272

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• Providesconsultationsintheareasofsafety,industrialhygiene,ergonomics,occupationalsafetyandhealthprograms,assistancetonewbusinesses,theSafetyandHealthAchievementRecognitionProgram(SHARP),andtheVoluntaryProtectionProgram(VPP).

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receivedcitationsandprovidescomplianceandtechnicalassistancebyphone.

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Appeals,InformalConferences• Providestheopportunityforemployerstoholdinformal

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PublicEducation&Conferences• Conductsconferences,seminars,workshops,andrule

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suchasconfinedspace,ergonomics,lockout/tagout,andexcavations.

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