Excavation General Awareness Safety Training Presentation Red Willow Production Co.

Transcription

1 Excavation General Awareness Safety Training Presentation Red Willow Production Co.

2 Learning Objectives Understand the purpose of our Excavation SOP - to protect employees and contractors when working around excavations Review the hazards created during excavation work Review the measures of control of the hazards created Provide you with information on what to look for when visiting an excavation site

3 Work Permit Requirement A Work Permit is required if you are planning to perform the following: Trenching Digging Boring Grading Fencing

4 Work Permit Requirement This Section of our Work Permit Addresses Excavations BE FAMILAR WITH OUR WORK PERMIT

5 JSA Approach Approach excavation safety like you would as if you were filling out a JSA The job/task has already been defined Your job is to identify the hazards and how to control them

6 Identifying the Hazards of excavation work Striking Underground Utilities Materials/soil/ equipment falling into excavations Explosions/Asphyxiation Falls into excavation Drowning Cave-ins 2a

7 Hazard Striking an Underground Utility Underground utilities include gas lines, waterlines and electrical lines. Accidental contact with these lines could result in serious consequences up to and including a fatality We must take measures to control and prevent line strikes

8 Control & Preventing Underground Utility Line Strikes Locating utilities prior to excavating is required Contact underground utility locate / one call service before starting excavation 811 National Colorado New Mexico Texas Utility owners must attempt to find exact location of utilities Depending on the state, you must call 2 or 3 days prior to excavating

9 Controlling & Preventing Underground Utility Strikes Proceed with caution if the exact location of utilities cannot be found Use a safe and acceptable means (pot holing) to locate exact location

10 Hazard -Materials/equipment falling into the excavation Materials/equipment falling into the excavation could injure a worker who might be in the excavation working. Examples of materials/equipment are: Vehicles/earth moving equipment driving into the excavation Rocks rolling into the excavation Tools falling into excavation Other materials such as wood blocks

11 Control & Preventing materials/spoil and equipment from falling into excavation Warn mobile equipment operators about the edge of the excavation site Place barricades, or cones around excavation Keep spoil (removed soil) at least 2 from excavation

12 Hazard Explosion or Asphyxiation An excavation in some cases should be treated like a confined space. The atmosphere inside an excavation can introduce a hazardous atmosphere due to: Internal combustion engines used near excavation Gas leaks from near by buried gas line

13 Control & Preventing Explosions and Asphyxiation Test the air of excavation sites more than 4 feet deep before entering If the atmosphere exceeds these parameters, do not enter <19.5% or >23.5% oxygen a combustible gas concentration >10% of the lower flammable limit. concentrations of hazardous substances that exceed threshold limit values If atmosphere is unacceptable wait for a few minutes and retest before allowing entry

14 Hazard Falls into Excavation Another potential hazard that could occur around an excavation is that and employee or visitor could fall into the excavation. This could injure the individual who falls and if they hit a worker in the excavation, there could be multiple injuries This could occur by walking too close to the excavation, not seeing it at night or trying to climb in or out of the excavation

15 Control & Preventing Falls If you must cross the excavation, have a proper ramp If left open over night, barricade or cover it so no one will walk into it

16 Control & Preventing Falls Trenches 4 or more feet deep need a safe means of entry and egress stairway ladder Ramps There must be a method of egress every 25 Means of egress must be fixed and secure

17 Hazard Water Accumulation-Drowning If an individual is working to repair a buried water line, the chances are pretty high that there will be water accumulating in the excavation until the pipe line is completely drained.

18 Control & Preventing Water Accumulation and Drowning Employees are prohibited from entering excavation sites with accumulated water unless adequate protection has been provided, such as pumps, sandbags, diversion ditches, dikes Or other means to prevent and/or remove surface water entering excavations and to drain adjacent areas.

19 Hazard Cave-ins Probably the most common hazard in excavations is cave-ins. A cubic foot of soil can weigh up to 125 pounds Each year more than 75 workers die in excavation cave-ins. What can we do to control and prevent these incidents?

20 Control & Preventing Cave - Ins Any excavation > than 5 in depth must be protected from cave in by one of the following protective methods unless it is in solid rock: Sloping Shoring Shielding

21 Protective systems Designing a protective system can be complex. OSHA regulations spell out specific requirements to be followed that make it a bit easier Specific Protective System requirements will be based on the type of soil, depth of excavation, water accumulation, traffic, etc.

22 Soil types There are 4 classifications of the soil : stable rock type A type B type C

23 Type A Examples of Soil types (clay, silty clay, sandy clay, clay loam, caliche and hardpan) Type B (angular gravel [crushed rock], silt, silt loam and sandy loam) Type C (weak soils or rock; granular material - least stable)

24 Control & Protecting against Cave in using Sloping and Benching Slope the excavation s sides to a safe angle The degree of slope is based on the type of soil Type A ¾ to 1 Type B 1 to 1 Type C 11/2 to 1

25 Control & Preventing Cave in using Sloping and Benching Benching systems excavate the sides of an excavation to form a series of horizontal levels or steps 16b

26 Sloping and benching If the soil type has been determined to be a type C soil, and the depth of the excavation is 5 feet, how wide will the excavation be at the top based on the following sloping requirements Type A ¾ to 1? Type B 1 to 1 Type C Soil Type C 11/2 to /1/2

27 Sloping and benching If the soil type has been determined to be a type C soil, and the depth of the excavation is 5 feet, how wide will the excavation be at the top based on the following sloping requirements x 1.5 = x 2 = 15 Type C Soil 15 = 1.5 = /1/2

28 Hydraulic Shoring Shoring systems support the sides of the excavation with: aluminum hydraulic shoring The OSHA regulations show Spacing based on soil type Tabulated data can be used

29 Shields Shields are another method to protect workers in an excavation. The shield provides no support The shield will be approved by a PE or tabulated data used

30 Bad Practice

31 Bad Practice

32 Summary There are many ways to be injured in an excavation: Striking Underground Utilities Materials/soil/ equipment falling into excavations Explosions/Asphyxiation Falls into excavation Drowning Cave-ins

33 Summary Each way to get hurt has a method of control Know the ways to get injured Know the ways to control each hazard