Msp - Cpt October 2009

8/14/2019 Msp - Cpt October 2009

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Americas Trench Box Builder

Trench Safety & OSHA

Excavation Standards

Trench Safety & OSHAExcavation Standards

Presented by Mark TurnerPresented by Mark Turner


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Todays Agendaodays Agenda Overview and Definitions

General Conditions & Responsibilities

Specific Excavation Requirements

Soil Classification

Selection & Use of Protective Systems

Identification of Hazards & StudentExercises

Exam & Evaluation


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Excavation Fatalitiesxcavation Fatalities& InjuriesInjuries

35

247

40

268

36

191

33

105

53

0

50

100

150

200

250

300

1999 2000 2001 2002 2003

Fatalities Injuries


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29 CFR 1926

Subpart P

Excavation

& Trenching


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MIOSHA

Part 9

Excavation,

Trenching

and Shoring


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The Power of OSHAhe Power of OSHA


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Competent Personompetent PersonOne who is capable of identifying

existing and predictable hazards in

the surroundings, or working

conditions which are unsanitary,

hazardous, or dangerous to

employees, and who hasauthorization to take prompt

corrective measures to eliminate

them.


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Role of the Competentole of the CompetentPersonerson Responsible for overall safety of

excavation

Knowledgeable in process of soil

classification Responsible for selection and use of

proper protective systems

Represents employer in OSHA visits Has authority to implement protective

measures


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Competent Personompetent Person(contd)contd) Identified in writing by employer

Key piece of any good safety program

Required on every site with excavation Has tools and publications necessary

to conduct job

Can be any trade or position withcompany


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DEFINITIONSEFINITIONS


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Adjacent Area & Spoildjacent Area & SpoilPileile

Adjacent area is equal tothe depth of the trench or

excavation.

Spoil piles, materials, and

equipment must be set

back at least 2 feet from

the edge of the excavation.

MIN.2Adjacent

Area

Spoil pile


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Minimum 2-feet back

Spoil, tools, pumps, etc.

must be set back at least 2feet from the edge of the

trench.


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DefinitionsDefinitions Excavation:

Any man-made cut, cavity,trench or depression in an earthsurface, formed by earth

removal.1926.650(b)


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DefinitionsDefinitions Trench:

a narrow excavation (in relation to its length) made below the

surface of the ground.. 1926.650(b)


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DefinitionsDefinitions Cave-in

Separation of a mass of soil or rock material from the side of an

excavation..1926.650(b)


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Specific Excavationpecific ExcavationRequirementsequirements Surface Encumbrances

Underground Installations

Access & Egress

Exposure to Vehicular Traffic

Exposure to Falling Loads

Hazardous Atmospheres

Water Accumulation

Stability of Adjacent Structures

Protection From Loose Rocks or Soil

Inspections

Fall Protection


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Surface EncumbrancesSurface Encumbrances

All surface encumbrances that are locatedso as to create a hazard to employees

shall be removed or supported.


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Underground InstallationsUnderground Installations

(UTILITIES)(UTILITIES)

Estimated Location Must Be Determined

Call 811

ExactLocation of Installation Must Be Determined bySafe & Acceptable Means

While Excavation is Open Exposed Utilities Must BeProtected, Supported or Removed.


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OVERHEAD POWER LINESOVERHEAD POWER LINES

Maintain 10-foot clearance from power

lines up to 50,000 volts and add 4inches more for each additional 10,000

volts!


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Access and EgressAccess and Egress

All Occupied Excavations Four (4) Feet or Deeper MustHave a Ladder, Ramp or Other Acceptable Means of

Access or Egress Within Twenty-five (25) Feet ofUnobstructed Lateral Travel of Employees.

>4'

Less than

25 ft.

Less than

25 ft.

4 ft

A d E ( td)A d E ( td)


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Access and Egress (contd)Access and Egress (contd)

LADDERSLADDERS

Ladders Must Be SECURE and Extend Three (3)

Feet Above the Point Where Workers Step Off.

Must have firm footing at

step-off point. Backfill oruse approved ramp.
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Access and Egress (contd)Access and Egress (contd)

RAMPSRAMPS

An Earth Ramp May Be Used in Place of a Ladder

if it Meets ALL of the Following Requirements

(A) The Ramp Material Shall Be Stable

(B) The Sides of the Excavation Above the Ramp Shall Be

Maintained To the Angle of Repose or Shored Along

Means of Egress

(C) The Degree of the Ramp Shall Not Exceed 45 Degrees

(D) Vertical Height Between the Floor of the Trench and

the Toe of the Ramp Shall Not Exceed 30 Inches


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Exposure to Vehicular TrafficExposure to Vehicular Traffic

Employees exposed to vehicular traffic shall beprovided with, and shall wear, warning vests orother suitable garments marked with or made of

reflectorized or high-visibility material.


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Exposure to Falling LoadsExposure to Falling Loads

Workers must stay outfrom underoverhead loads.


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Exposure to Hazardous AtmospheresExposure to Hazardous Atmospheres

Excavations greater than 4 feet deep, which could

contain a hazardous atmosphere, must be tested

before anybody enters.

Test from outside the trenchOxygen must be at least

19.5% but should be 20.9%Flammables levels less than

10% LEL

Toxic materials less thanPEL/TLV
http://www.ci.glendora.ca.us/water_commission/cip/sierramadre/30%20Inch%20Welding%20RASIC.JPG


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Exposure to Hazardous AtmospheresExposure to Hazardous Atmospheres

Atmosphere Should Be Tested if Working in or Around The

Following Areas. Or, If the Competent Person Believes There isa Potential For A Hazardous Atmosphere.

LandfillsChemical PlantsWaste Water Treatment PlantsPetroleum RefineriesBuried Gasoline/Diesel TanksSwamps
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Exposure to WaterExposure to Water

AccumulationAccumulationOSHA SUBPART POSHA SUBPART P

Employee Exposure Employees are not to be exposed to accumulating water or

water that has accumulated

Water Removal Monitoring Competent/Qualified person is to confirm that mechanical water

removal devices (pumps, etc.) are functioning properly.

Contracted dewatering companies shall instructcompetent/qualified person on proper system operation

Natural Drainage Site shall be graded so water runs away from trench and/or excavation.


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Effects of Waterffects of WaterAccumulationccumulation


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STABILITY OF ADJACENTTABILITY OF ADJACENTSTRUCTURESTRUCTURES A Registered Professional Engineer (RPE) is

Required to Design Underpinning for Buildings and

Other Load Bearing Structures

Competent Person Shall Make Sure All Sidewalks,

Pavements, and Walkways Are Supported


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Exposure to Loose Rock orxposure to Loose Rock orSoiloil No Employee Shall Be Exposed to Hazards

Associated With Loose Rock or Soil Sliding or Falling

From Trench Walls, face or Bank.

Competent Person Must Ensure That Sides of

Excavation or Trench Are Scraped Clean.


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INSPECTIONSNSPECTIONS Competent Person Must Make an Inspection of the

Excavation and Adjacent Area at Least Once Daily at

the Beginning of the Shift

Additional Inspections Must Be Made After

Rainstorm or Other Hazard Increasing Event.

Inspections Must Include: Soil Type and Composition (If not assumed Type C)

Condition of Open Trenches

Condition of Manufactured Protective Systems

WRITE DOWN ALL INSPECTIONS

PERFORMED


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FALL PROTECTIONALL PROTECTIONAll Walkways Crossing Trench or Opening Six (6) Feet

Deep or Greater and 30 Inches Wide or Wider Must

Have Handrails and/or Guardrails and Toeboards.

Walkways Must be Designed by the Competent

Person for the Sole Purpose of Employee Use


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SOILOILCLASSIFICATIOLASSIFICATION


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Weight of Soileight of Soil

12

12

12

ONE

CUBIC FT.

One cubic foot

(12x 12x 12)

weighs between

90 to 140

pounds.

One cubic yard

(36x 36x 36)

weighs as

much as asmall pickup

truck.


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Appendix A Soil

Classification

Soil definitions

Soil tests based on site and

environmental conditions

Descriptions of visual and

manual tests for classifying

soils

Soil classification determinedby the competent person


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Soil Classificationoil ClassificationThe competent person must

make at least one visual and one

manual soil test as a basis for

soil classification.

Unless the soil is considered

to be 'Type C' and treated as a

'C'


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SoiloilDefinitionsefinitions Apparent

cohesion

Cemented soil Plastic

Saturated soil

Submerged soil


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General Rules Regarding Soileneral Rules Regarding SoilSampleample Sample must represent mean composition of

total soil type.

Sample must be taken from spoil pile

Sample cannot have been out of ground for

longer than one hour


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Cohesive or Granular

Clay or soil with ahigh clay content

Does not crumbleand can be

excavated withvertical sides

Plastic whenmoist, hard to

break when dry

Gravel, sand, orsilt with little orno clay content

No cohesivestrength

Cannot bemolded when

moist andcrumbles easilywhen dry


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Cohesive vs Granular

Type CUnconfined

Compressive

Strength

Type

A B CGreater than

1.5 tsf

.5 1.5

tsf

Less than

0.5 tsf


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UnconfinedCompressive StrengthThe unconfined compressive strength

of a soil is the load-per-unit area atwhich a soil will fail in compression.

It can be estimated in the field

by using pocket penetrometer,

or other field and laboratory

tests.


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Manual Soil Testsanual Soil Tests Thread or ribbon

tests

Pocket penetrometer

Laboratory Tests


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PocketocketPenetrometerenetrometerDevice used to estimate the

unconfined compressive strength ofsoil. Must be used in saturated or

nearly saturated cohesive soil.


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Visual Testsisual Tests Observe excavated soil for

particle size and clumping

Observe excavations sides for

cracks, spalls, layered systems Observe adjacent areas for

existing utilities and underground

structures, previously disturbedsoil, surface water, and sources of

vibration


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Stable Rocktable Rock

Caution: Stable rock is generally not

accepted as a soil type by OSHA.

Natural solid mineral matter that can

be excavated with vertical sides and

remain intact while exposed.


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OSHA Type A SoilSHA Type A SoilCohesive soil withan unconfined

compressive

strength of 1.5

tons per square

foot (tsf) or

greater, e.g., clay,

silty clay,cemented soils.


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No soil is Type A ifo soil is Type A ifit:t: Is fissured or cracked

Is subject to vibration

Has been previously disturbed Is subject to other factors making

it less stable, such as water


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OSHA Type B SoilSHA Type B Soil Cohesive soil with unconfined

compressive strength greater than0.5 tsf but less than 1.5 tsf

Granular cohesionless soils, e.g.,gravel, silt, silt loam or sandy loam

Previously disturbed soils, exceptthose otherwise classified as Type C

Type A fissured or subject tovibration

Unstable dry rock


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OSHA Type C SoilSHA Type C Soil Cohesive soil with unconfinedcompressive strength of 0.5 tsf or less

Granular soil including gravel, sand,

and loamy sand

Submerged soil or soil from whichwater is freely seeping

Submerged rock that is not stable


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Every employee working in a trench or

excavation over 5 feet deep must be

protected from a cave-in by a protectivesystem:

Sloping or benching walls

Shoring to support walls

Shields to protect occupantsinside when

walls cave-in


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Competent Peron can Design Protective

System for Depths Up To 20 FT. Depths Greater Than 20 FT Require Design

by Registered Professional Engineer or

Manufacturers Tabulated Data


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Protective Systems

Shoring

Shields

Sloping


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Sloping a Trenchloping a Trench


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Benchingenching


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NUCA CPT Copyright

2006

Appendix B

Sloping and Benching

Soil typeMaximum allowable

slopes (H:V) - Less than

20 feet

Stable Rock Vertical (90

degrees)Type A

Type B

Type C

: 1 (53

degrees)

1:1 (45 degrees)

1:1 (34

degrees)

Table B-1: Maximum Allowable Slopes

Sl i T A


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NUCA CPT Copyright

2006

Sloping Type AMaximum depth 20 feet

Sl i T B


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NUCA CPT Copyright

2006

Sloping Type BMaximum depth 20 feet

Sl i T C


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NUCA CPT Copyright

2006

Simple Slope

Sloping Type CMaximum depth 20 feet


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Trench Shields


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General Description

A trench shield is a movable box strong enoughto protect the employee inside, but light enoughto handle easily in the trench

Ideally, the width of a trench is approximately 4

in. wider than the width of the trench shield toreduce possible friction during movement.Thus, the trench shield cannot effectivelyprevent soil cave-ins outside the box

The application depth in the trench or design

pressure shall be clearly marked on the shield.


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TABULATED DATA MUST BE AVAILABLE ATJOBSITE DURING CONSTRUCTION, SET-UP, USEAND REMOVAL OF SHIELDModel # of Shield

Limitations

Must be Certified

by RPE

Serial # of Shield

Soil Type

Max. Depth

Soil Description

Tabulated Data Modular


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Tabulated Data Modular

System

Shield must extend to grademus ex en o gra e


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level or be combined withevel or be combined withproper sloping. (Angle ofroper sloping. (Angle ofRepose)epose)


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Trench Shield Combined with Sloping

Slope must start 18 below top of trench shield

Slope must be correct for representative soil


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Using Single Trench Shield


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Using Stacked Trench Shieldssing Stacked Trench ShieldsShields must extend to grade or above grade or be combined with

sloping


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Shields must be stacked perhields must be stacked permanufacturers recommendations.anufacturers recommendations.

Trench Shields Can Be Held Up


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To 2 FT Above Trench BottomProvided Trench Shield Is Rated For Full Depth

There is No Visible Loss of Soil Under

or Behind the Shield


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Movement of Shieldovement of Shield An Employee Shall Not Be Allowed in Shields

When Shields are Being Installed, Removed

or Moved Vertically. 1926.652(g)(2)


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Shoringhoring


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Hydraulic ShoresHydraulic Shores


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Hydraulic Shoresydraulic Shores


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Hydraulic Shoresydraulic ShoresThrust pressure fans out through trenchThrust pressure fans out through trench

wall, interlocking in an arch fromwall, interlocking in an arch from

adjacent shores.adjacent shores.

TOP VIEW


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Shoring Selection Guidehoring Selection GuideTABULATED DATAABULATED DATA


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Selection Guide: NotesSelection Guide: Notes

1.1. Utilize Efficiencys 2 in. diameter hydraulic cylinders with standard or heavy duty extension system as required for desired excavationUtilize Efficiencys 2 in. diameter hydraulic cylinders with standard or heavy duty extension system as required for desired excavationwidth. Trenches wider than 9-4 (112) require Efficiencys Steel Oversleeves extending the full, collapsed length.width. Trenches wider than 9-4 (112) require Efficiencys Steel Oversleeves extending the full, collapsed length.

2.2. Plywood sheeting shall consist of 1.125 in. CDX plywood or .75 in., 14 ply Arctic Birch.*Plywood sheeting shall consist of 1.125 in. CDX plywood or .75 in., 14 ply Arctic Birch.*

3.3. Plywood sheeting required if raveling or sloughing is likely to occur. (see installation diagrams)*Plywood sheeting required if raveling or sloughing is likely to occur. (see installation diagrams)*

4.4. Plywood sheeting shall be used.*Plywood sheeting shall be used.*

5.5. Material can stand with unsupported vertical sidewalls long enough for shoring installation.Material can stand with unsupported vertical sidewalls long enough for shoring installation.

6.6. Vertical shoring shall be Efficiencys standard or heavy duty vertical rail sections. (see pg 6).Vertical shoring shall be Efficiencys standard or heavy duty vertical rail sections. (see pg 6).

7.7. Extra Heavy Duty Extensions Required.Extra Heavy Duty Extensions Required.


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HYDRAULIC SHORINGYDRAULIC SHORING


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Installationnstallation

Placetheshorenearthetrenchedgeintheopenpositionwiththecylinderraildown.Openthevalveonthepumpcan1/4turn.AttachthefemalequickPlacetheshorenearthetrenchedgeintheopenpositionwiththecylinderraildown.Openthevalveonthepumpcan1/4turn.Attachthefemalequick

connectfittingonthepumphosetothemalefittingonthetopcylinder.Putthereleasetoolthroughthehandleonthelowerrailwiththehookpositionedtoconnectfittingonthepumphosetothemalefittingonthetopcylinder.Putthereleasetoolthroughthehandleonthelowerrailwiththehookpositionedto

grabthehandle.Foldtheshorebypullingthetoprail towardyoubyhand.Lowertheshoreintothetrenchwithhookgrabthehandle.Foldtheshorebypullingthetoprail towardyoubyhand.Lowertheshoreintothetrenchwithhook

Releasethetoprail andallowshoretocompletelyunfold.Releasethetoprail andallowshoretocompletelyunfold.

Theshorewill lockitself intoopenposition.Theshorewill lockitself intoopenposition.


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Installationnstallation

Whileholdingtheshoreat thedesiredheight, closethe1/4turnreleasevalveonpumpcanWhileholdingtheshoreat thedesiredheight, closethe1/4turnreleasevalveonpumpcan

andpumpthehandleonthecantobuildpressurebetween750-1500PSI.andpumpthehandleonthecantobuildpressurebetween750-1500PSI.

Toremovethehose, placethereleasetool flangebehindthecollarofthequickdisconnectfitting. Thehookwill betowardToremovethehose, placethereleasetool flangebehindthecollarofthequickdisconnectfitting. Thehookwill betoward

you. Pull thetool towardyourself, usingthehookasapivot, thehosewill comeoff. Afterhoseisdisconnected, cliphosetoyou. Pull thetool towardyourself, usingthehookasapivot, thehosewill comeoff. Afterhoseisdisconnected, cliphoseto

thetopofpump. Openvalveonpumpandmovetothenextshore.thetopofpump. Openvalveonpumpandmovetothenextshore.


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Removalemoval

Toremovetheshore, placetheremoval tool throughthehandlewiththehookfacingtheToremovetheshore, placetheremoval tool throughthehandlewiththehookfacingthe

trench. Placetheendof thetool overthesamefittingwherehosewashooked.trench. Placetheendof thetool overthesamefittingwherehosewashooked.

Pushthetool awayfromyouagainst thehandle. Thetool willPushthetool awayfromyouagainst thehandle. Thetool will

depressthefittingandreleaseasmall amount of fluid.depressthefittingandreleaseasmall amount of fluid.


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RemovalemovalRemovefromtrenchbypullingonesidewithreleasetool andRemovefromtrenchbypullingonesidewithreleasetool and

theother sidewiththeremoval hook.theother sidewiththeremoval hook.

Theshorewill foldasit ispulledout. Removetools, foldTheshorewill foldasit ispulledout. Removetools, fold

shoreflat, andcarrytothenext installationspot.shoreflat, andcarrytothenext installationspot.


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Hydraulic Walersydraulic Walers


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Slide Rail Systemlide Rail System


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4-Sided Pit-Sided Pit


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Linear Multi-Bayinear Multi-Bayw/ ClearSpan/ ClearSpan WalerWaler


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Parallel Beam witharallel Beam withSpreaderspreaders


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ClearSpanlearSpan SystemSystem


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Shore-Trak with 4-Sided Pit

Slide Rail Shore-lide Rail Shore-Trakrak


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STUDENTTUDENTEXERCISESXERCISES


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Evaluate This Trenchvaluate This Trench


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CPT SummaryPT SummaryOSHA standards arefound in 1926Subpart P

Every employee working in a trench or


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y p y g

excavation over 5 feet deep must be

protected from a cave-in by a protectivesystem:

Sloping or benching walls Shoring to support walls

Shields to protect occupantsinside when

walls cave-in


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OSHA RegulationsSHA RegulationsMeans of Egresseans of Egress

A stairway, ladder, ramp or other safe

means of exit is required in trenches4 ft. or deeper.

Access must be within 25 ft. of

lateral travel for employees.


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CPT SummaryPT Summary Every company working in an

excavation and/or trench is required to

have an identified Competent Person


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CPT SummaryPT Summary Competent Person responsible for:

Inspections of soils and excavation safety

Selection and use of proper protective system

Limitation of exposure to accumulating water

Overall safety of excavation


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CPT SummaryPT Summary Adjacent area must be kept clear of non-

essential materials and equipment

Spoil piles, equipment and materials must

be placed a minimum of 2 ft from edge

Means of access and egress must be

within 25 ft of all employees in excavations

4 ft or greater.


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CPT SummaryPT Summary Ladders must extend 3 ft above the point

where workers step off.

Ladders must be secure.

Trench shields may be set a maximum of 2 ftabove trench bottom.

If sloping is used above trench shield, slope

must start 18 in below top of trench shield


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QPT SummaryPT Summary Tabulated data must be on site for all

manufactured protective systems during

set-up, installation and use.

Competent person must test atmosphere ifthere is a reasonable expectation of

contamination.

Competent person must make a minimumof one inspection at beginning of shift.


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Americas Trench Box Builder

Trench Safety & OSHAExcavation StandardsTrench Safety & OSHAExcavation Standards


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Msp - Cpt October 2009

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Transcript of Msp - Cpt October 2009