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copyright 1999 Sierra Safetyworks 1

SUBPART P

1926.650 - 1926.652

EXCAVATIONS


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DefinitionExcavation Vs. Trench

Atrenchis defined as a narrow excavationmade below the surface of the ground. Thedepth is normally greater than the width withthe width at the bottom of the trench being nowider than 15

Anexcavationis defined as any man-madecavity, trench, or depression in the earthsurface formed by earth removal

Therefore, it can be assumed that alltrenches are excavations, but not allexcavations are trenches


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Do You See Safe Work

Practices in Place Here?


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OSHAs GREATEST HIT$Most Commonly Cited - 1999

1926.652(a)(1)Protection provided from cave-insin excavations

1926.651(k)(1)Daily inspections by competent

person of excavations & protective systems1926.651(c)(2)Means of egress provided from

trench excavations

1926.651(j)(2)Protection from excavated material

or equipment falling into excavations1926.651(k)(2)Competent person inspection

Employees removed from hazard


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Are These Goodor Bad Examplesof Excavation Safety?


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Examples of ExcavationSafety?


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Major Compliance Issues ofSubpart P

Scope, Application, & Definitions (includingCompetent Person) 1926.650

General Requirements 1926.651

Requirements for Protective Systems

1926.652

Appendix A - F Includes Soil classification,sloping and benching, timber shoring,aluminum hydraulic shoring, alternatives totimber shoring, and selection of protectivesystems


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Scope, Application & DefinitionCompetent Person

The single most important definitioncontained in this Subpart is that of

Competent Person

A competent person is defined as one whois capable of identifying existing andpredictable hazards in the surroundings, or

working conditions which are unsanitary,hazardous, or dangerous to employees andwho has the authority to take promptcorrective measures to eliminate them


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What Makes you an ExcavationCompetent Person?

You MUSThave specifictraining in and beknowledgeable about:

Soil Typing & analysis The different kinds of

protective systems &their proper use

Hazard recognition

When a registered P.E. isrequired

Knowledge of Subpart P


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What Makes you an ExcavationCompetent Person?

AND HAVE AUTHORITY


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Did The Competent Person DoTheir Job Here?


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General Requirements ofSubpart P

Surface encumbrances must be supported orremoved if they pose a hazard to workers

All underground utilities or other similar type

installations must be located prior to anyexcavation beginning. Those same may needto be supported, removed or protected


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A Th G d B d E l


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Are These Good or BadExamplesof Access & Supporting Utilities?


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Are These Good or BadExamplesof Access & Supporting Utilities?


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Are These Good or BadExamples

of Access & Supporting Utilities?

E ll t E l f S t d


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Excellent Examples of SupportedUtilities Excavations

f


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Excellent Examples ofSupported Utilities Excavations

ll l f


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ll l f


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E l f B i P i


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Examples of Barrier ProtectionAround the Excavation Perimeter

Barricades or equivalent around excavations tokeep employees from falling in

Similar measures to be taken to keep vehiclesor equipment from going into excavation

G l R i t f


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Workers cannot be underneath any loadhandled by digging or lifting equipment

Warning systems must warn equipmentoperators of excavations (I.e. barricades, etc)

Excavations must be checked for possible

hazardous atmospheres

G l R i t f


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Workers must not work in excavationsthat contain water

Any structure adjacent to an excavationmust be properly supported to preventcollapse

Workers must be protected from loosematerials or soil going into theexcavation


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Goodor BadExamples?


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Goodor BadExamples?


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Goodor BadExamples?


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Goodor BadExamples?

G l R i t f


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All excavations & anyprotective equipmentused in same must be

inspected on a dailybasis by a competentperson & must occurprior to any starting

Walkways equippedwith guardrails must beprovided where workersor equipment cross over

excavations

R i t f P t ti


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Requirements for ProtectiveSystems

Any worker in an excavation shall beprotected from cave-ins by an adequateprotective system except when:

Excavation made entirely in stable rock Excavation less than 5 deep & inspection by

competent person reveals no cave-in hazard

All protective systems to have capacity to

resist without failure all loads that areintended or reasonably could be expectedto be applied or transmitted to theprotective system

A P P ti B i


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Are Proper Precautions BeingTaken in These Examples?

A e P ope P e tion Being


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Are Proper Precautions Being


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Design of all Protective Systems

Design of sloping &benching systems

All sloped 1.5/1(34o)

Appendix A & B Tabulated data

Design by P.E.

Materials & Equipment

All approved by competentperson

Manufactured equipmentused per mfrs. Specs

unless approved in writing

Design of support,shield, & otherprotective systems Timber shoring to be

per appendix A & C Mfrs. Tabulated data

for support or shields

Hydraulic shoring per

mfr or appendix D All tabulated data kept

on site during work

Design by registeredP.E. & kept on site

A Good Example of an


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A Good Example of anEngineered Shoring Plan

Conventional sloping wouldnt work because ofadjacent buildings & road that had to remain open

Existing utilities were located and supported

P.E. shoring plan followed exactly

Subpart P


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Subpart PAppendix A Requirements

Classification of soil & rock depositsAll rock & soil deposits must be classified

by a competent person as either stable

rock, type A, type B, or type CThese classifications must be made on the

basis of at least 1 visual & 1 manual test

Visual Tests Manual TestsParticle size Pocket penetrometer

spalling & fissures roll test(cohesiveness)

water resence sedimentation test

Soil Classification


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Soil ClassificationType A Soil

Cohesive soil with anunconfined compressivestrength of 3000# persq. foot or greater

Clay, silty clay, cementedsoils (non-granular)

Cannot be Type A if: Unstable dry rock

Previously disturbed soil Is fissured

Subject to vibration

layered with slope > 4/1

Soil Classification


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Soil ClassificationType B Soil

Cohesive soil with anunconfined compressivestrength of 1000-3000#per square foot

Granular cohesionlesssoils: silt, silt loam, sandyloam

Can be Type B soil if: Unstable dry rock

Type A fissured or subjectto vibration

Layered with slope < 4/1


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Would You Work in These


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WouldYou Work in TheseTrench Boxes?


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Would You Work in These


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WouldYou Work in TheseTrench Boxes?

Good and Bad Examples of Trench


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Goodand BadExamples of Trenchand Excavation Protection


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An Excellent Example of all


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An Excellent Example of allFacets of Excavation Safety

Good example of shoring /lagging

Good guardrail system around upper perimeter

Good impalement protection at lower grade

excavation 01

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