Excavation & Trenching L&I v1

7/25/2019 Excavation & Trenching L&I v1

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Excavations & Trenching

1

OSHA1926

Subpart P

Bureau of Workers CompPA Training for Health & Safety

(PATHS)

PPT-011-01


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Definitions

Excavation a man-made cut, cavity, trench ordepression formed y earth remova!"

Trench a narro# excavation" The depth is greaterthan the #idth, ut not #ider than 1$ feet"

%hie!d - structure a!e to #ithstand a cave-in andprotect emp!oyees 'a!so ca!!ed ox("

%horing - structure that supports the sides of anexcavation and protects against cave-ins"

%!oping - techni)ue that emp!oys a specific ang!eof inc!ine on the sides of the excavation" The ang!evaries ased on assessment of impacting site

factors"

*PPT-011-01


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Excavation +aards

.ave-ins are the greatest ris/

ther haards inc!ude

sphyxiation due to !ac/of oxygen

2nha!ation of toxic materia!s

3oving machinery near the edgeof the excavation 'can cause aco!!apse(

ccidenta! severing ofunderground uti!ity !ines"

4ire

PPT-011-01


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2n5ury and Death

Excavating is one of themost haardousconstruction operations

3ost accidents occur intrenches $-1$ feet deep

There is usua!!y no #arningefore a cave-in

6PPT-011-01


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$

4ocus of Training

The greatest ris/ at an excavation

+o# to protect emp!oyees from cave-ins

4actors that pose a haard to emp!oyees

#or/ing in excavations The ro!e of a competent person at an

excavation site

PPT-011-01


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Protection of Emp!oyees

Emp!oyees shou!d e protected from cave-ins y usingan ade)uate!y designed protective system"

Protective systems must e a!e to resist a!! expected

!oads to the system"

7PPT-011-01


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8e)uirements forProtective %ystems

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#e!!-designed protective systemCorrect esign of!

" Sloping an #enching systems" Support systems" Shiel systems

" $ther protecti%e systems+

Appropriate hanling of materials an euipment+

Attention to correct installation an remo%al=Protection of employeesat e'ca%ations

PPT-011-01


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Design of Protective %ystems

The emp!oyer sha!! se!ect and construct

%!opes and configurations of s!oping andenching systems"

%upport systems, shie!d systems and other

protective systems" %hie!d - .an e permanent or porta!e" !so

/no#n as trench ox or trench shie!d"

%horing - %uch as meta! hydrau!ic, mechanica!or timer shoring system that supports the

sides" %!oping - 4ormed sides of an excavation that

are inc!ined a#ay from the excavation"

:PPT-011-01


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Protect Emp!oyees Exposed toPotentia! .ave-ins

%!ope or ench the sidesof the excavation"

%upport the sides of the

excavation"

P!ace a shie!d et#een theside of the excavation andthe #or/ area"

;PPT-011-01


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.ave-in +aard

This excavationhas inade)uate

support posts and

egress access"

Inadequate protective system

PPT-011-01


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2nade)uate Protective %ystem

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This #or/er is in atrench, #ith no

protective system,

that is neither s!opednor enched, and hasno means of egress"

PPT-011-01


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4actors 2nvo!ved in Designinga Protective %ystem

%oi! c!assification

Depth of cut


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%horing

=enera!

Provides a frame#or/ in #hich to #or/

>ses #a!!s, cross races and uprights

%upports excavation #a!!s

%+ ta!es provide shoring data

3ust /no# soi! type

3ust /no# depth and #idth of excavation

3ust e fami!iar #ith the %+ ta!es

1PPT-011-01


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Trench %hie!d

trench shie!d

'a!so ca!!ed atrench ox(#as ui!t

around this#or/ area"

16PPT-011-01


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+ydrau!ic Trench %upport

>sing hydrau!ic 5ac/s, theoperator can easi!y dropthe system into the ho!e"

nce in p!ace, hydrau!icpressure is increased to/eep the forms in p!ace"

Trench pins are insta!!edin case of hydrau!icfai!ure"

1$PPT-011-01


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3ateria!s and E)uipment

E)uipment used forprotective systems must nothave damage or defects thatimpair function"

2f e)uipment is damaged, acompetent person mustexamine it to see if it issuita!e for continued use"

2f not suita!e, remove it

from service unti! aprofessiona! engineerapproves it for use"

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Trench ?ox

PPT-011-01


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Protection from @ehic!es

2nsta!! arricades

+andAmechanica! signa!s

%top !ogs

=rade soi! a#ay fromexcavation

4ence or arricade

trenches !eft overnight

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1:

+aardous .onditions

They shou!d note #or/ing under

this crane"

The #eight andviration of the

crane ma/es this

a very haardouscondition"

PPT-011-01


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%poi! Pi!es

DonBt p!ace spoi!s #ithin t#ofeet from edge of excavation"

3easure from nearest partof the spoi! to the excavationedge"

P!ace spoi!s so rain#ater runsa#ay from the excavation"

P!ace spoi! #e!! a#ay fromthe excavation"

1;PPT-011-01


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*0

ther Excavation +aards


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+aardous tmosphere

Test excavations morethan four feet efore anemp!oyee enters the

excavation forF xygen deficiency

F +igh comusti!e-gas concentration

F +igh !eve!s of otherhaardoussustances

*PPT-011-01


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3eans of Egress

stair#ay, !adder orramp must e presentin excavations that arefour or more feet deep,

and must e #ithin *$feet of emp!oyees"

The !adder shou!dextend three feet

aove the excavation"

*6

This ladder does not meet the

requirements of the standard

PPT-011-01


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*$

ccess and Egress

These t#o !adders,#hich are !ashedtogether, are not

an ade)uatemeans of egress"

Gadders shou!dextend three feet

aove the top ofthe excavation"

PPT-011-01


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Protection from 4a!!s, 4a!!ing Goadsand 3oi!e E)uipment

2nsta!! arricades"

>se handAmechanica! signa!s"

=rade soi! a#ay from excavation"

4ence or arricade trenches !eft overnight"

>se a f!agger #hen signs, signa!s and arricadesare not enough protection"

*7PPT-011-01


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*9

Must have had specific training in

and be knowledgeable about:

oils classification

he use of protective systems

he requirements of the standard

Must be capable of identifying ha"ards

and authori"ed to immediatelyeliminate them#

.ompetent Person

PPT-011-01


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2nspections of Excavations

competent person must ma/edai!y inspections of excavations,areas around them andprotective systems

?efore #or/ starts and asneeded

fter rainstorms, high #indsor other occurrence #hich

may increase haards


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2nspections of Excavations'cont"(

2f a competent person findsevidence of a possi!e cave-in,indications of fai!ure of protectivesystems, haardous atmospheres

or other haardous conditions Exposed emp!oyees must e

removed from the haardousarea"

Emp!oyees may not return unti!the necessary precautions haveeen ta/en"

*;PPT-011-01


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%ite Eva!uation P!anning

?efore eginning excavation

Eva!uate soi! conditions

.onstruct protective systems

Test for !o# oxygen,haardous fumes and toxicgases

Provide safe in and outaccess

.ontact uti!ities

Determine the safetye)uipment needed

0

Fissure

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1

%ummary

The greatest ris/ in an excavationis a cave-in"

Emp!oyees can e protectedthrough s!oping, shie!ding and

shoring the excavation"

competent person is responsi!eto inspect the excavation"

ther excavation haards inc!ude#ater accumu!ation, oxygendeficiency, toxic fumes, fa!!s and

moi!e e)uipment"

PPT-011-01


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*

Huestions

PPT 011 01

Documents

Excavation & Trenching L&I v1