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Questions and Answers
A cubic yard of soil can weigh as much as:
A cubic yard of soil can weigh as much as:
To be classified as type A, the soil cannot be:
To be classified as type A, the soil cannot be:
When your trench is deeper than 4 ft and hazards may be present, air monitoring must be done before entry.
When your trench is deeper than 4 ft and hazards may be present, air monitoring must be done before entry.
True
A soil cannot be Type A if it is:
A soil cannot be Type A if it is:
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Which of the following are common soil classification tests?
Which of the following are common soil classification tests?
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Type A soils are usually clay and cemented soils such as caliche and hardpan.
Type A soils are usually clay and cemented soils such as caliche and hardpan.
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Each of the following is Type B soil EXCEPT:
Each of the following is Type B soil EXCEPT:
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The definition of type C-60 soil allows the competent person to use vertical shores or other protective systems.
The definition of type C-60 soil allows the competent person to use vertical shores or other protective systems.
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What is the most important distinction between stable rock types A&B and type C?
What is the most important distinction between stable rock types A&B and type C?
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What is a defining feature of stable rock?
What is a defining feature of stable rock?
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OSHA requires a competent person to perform two visual and two manual tests on a soil sample.
OSHA requires a competent person to perform two visual and two manual tests on a soil sample.
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Aluminum hydraulic shoring permits both installation and removal without entering the trench.
Aluminum hydraulic shoring permits both installation and removal without entering the trench.
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Shores must be pumped to a minimum of 750 pounds of pressure but more is recommended.
Shores must be pumped to a minimum of 750 pounds of pressure but more is recommended.
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Type B soils afford how many options of protection?
Type B soils afford how many options of protection?
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Which soil type is the most common?
Which soil type is the most common?
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Which of the following statements is true of kickout?
Which of the following statements is true of kickout?
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Mixed oak timber has a greater bending strength per square inch than Douglas fir.
Mixed oak timber has a greater bending strength per square inch than Douglas fir.
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In type C soil, the angle of repose is very low. How many degrees must the angle be?
In type C soil, the angle of repose is very low. How many degrees must the angle be?
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What is the depth at which an excavation needs attention from a registered professional engineer?
What is the depth at which an excavation needs attention from a registered professional engineer?
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Placing a shield between the side of an excavation and the work area can minimize the risk in the event of a cave-in.
Placing a shield between the side of an excavation and the work area can minimize the risk in the event of a cave-in.
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Shoring and shielding can be custom built from tabulated data approved by a registered PE.
Shoring and shielding can be custom built from tabulated data approved by a registered PE.
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The struts of a screw jack system must be adjusted manually; this creates a hazard because the worker is required to:
The struts of a screw jack system must be adjusted manually; this creates a hazard because the worker is required to:
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All systems have a set of manufacturer's tabulated data for proper design and installation.
All systems have a set of manufacturer's tabulated data for proper design and installation.
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When using a ladder in a trench, it must be:
When using a ladder in a trench, it must be:
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A surface encumbrance is anything that could create a ___ in or around a trench.
A surface encumbrance is anything that could create a ___ in or around a trench.
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Walkways must have handrails when at ___ or more above a lower level.
Walkways must have handrails when at ___ or more above a lower level.
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A competent person must inspect all excavations, adjacent areas, and protective systems daily, ___, and as needed throughout the shift.
A competent person must inspect all excavations, adjacent areas, and protective systems daily, ___, and as needed throughout the shift.
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Establishing eye contact with your equipment operator is a general safety principle when working outside the working radius.
Establishing eye contact with your equipment operator is a general safety principle when working outside the working radius.
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Being dangerously close to a falling load is allowed.
Being dangerously close to a falling load is allowed.
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Each of the following is true of accumulating water hazards EXCEPT:
Each of the following is true of accumulating water hazards EXCEPT:
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Warning systems for mobile equipment include barricades, hand signals, and stop logs.
Warning systems for mobile equipment include barricades, hand signals, and stop logs.
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All surface encumbrances must be removed or supported within:
All surface encumbrances must be removed or supported within:
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Each of the following is true of underground installations EXCEPT:
Each of the following is true of underground installations EXCEPT:
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When exposed to vehicular traffic, your excavation site must have:
When exposed to vehicular traffic, your excavation site must have:
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Which of these did OSHA recommend?
Which of these did OSHA recommend?
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The competent person must have authority to correct hazards. Who gives the competent person this authority?
The competent person must have authority to correct hazards. Who gives the competent person this authority?
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The competent person must be a superintendent, foreman, or project manager.
The competent person must be a superintendent, foreman, or project manager.
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The topic is about the practical application of the Fed-OSHA Excavation standard regarding:
The topic is about the practical application of the Fed-OSHA Excavation standard regarding:
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After identifying a possible cave-in, protection system failure, or hazardous atmosphere, the competent person:
After identifying a possible cave-in, protection system failure, or hazardous atmosphere, the competent person:
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The OSHA Soils Standard applies to each of these EXCEPT:
The OSHA Soils Standard applies to each of these EXCEPT:
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What do you think was the primary cause of this accident?
What do you think was the primary cause of this accident?
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What could have been done to prevent this fatality?
What could have been done to prevent this fatality?
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"Free-seeping" soil is considered submerged soil.
"Free-seeping" soil is considered submerged soil.
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Which soil cannot be molded when moist and crumbles easily when dry?
Which soil cannot be molded when moist and crumbles easily when dry?
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Soil which fractures along definite planes or exhibits open cracks is:
Soil which fractures along definite planes or exhibits open cracks is:
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OSHA made four recommendations in which responsibility was clearly identified. To whom were OSHA's recommendations directed?
OSHA made four recommendations in which responsibility was clearly identified. To whom were OSHA's recommendations directed?
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An unsupported excavation can create an unbalanced stress, causing:
An unsupported excavation can create an unbalanced stress, causing:
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When the vertical face of a trench shears along a tension crack line, it is known as:
When the vertical face of a trench shears along a tension crack line, it is known as:
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Tension cracks are rarely a sign of imminent trench failure.
Tension cracks are rarely a sign of imminent trench failure.
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Boiling is an upward water flow into the bottom of the cut.
Boiling is an upward water flow into the bottom of the cut.
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Having or squeezing can occur even when shoring or shielding has been properly installed.
Having or squeezing can occur even when shoring or shielding has been properly installed.
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An increase or decrease in moisture can both damage trench stability.
An increase or decrease in moisture can both damage trench stability.
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Time and weather are not major influences in soil stress.
Time and weather are not major influences in soil stress.
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The 'adjacent area' is the area on either side of the trench cut equal to the depth of the trench.
The 'adjacent area' is the area on either side of the trench cut equal to the depth of the trench.
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Layered systems may have layers of different soil types, which become especially problematic when layers slope or dip downward.
Layered systems may have layers of different soil types, which become especially problematic when layers slope or dip downward.
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____ loads are any increased in weight in the adjacent areas next to the cut.
____ loads are any increased in weight in the adjacent areas next to the cut.
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About how much does one cubic yard of soil weight?
About how much does one cubic yard of soil weight?
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When should type A be downgraded to type B or lower?
When should type A be downgraded to type B or lower?
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For testing, soil suspected to be Type A should:
For testing, soil suspected to be Type A should:
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Granular soils without cohesion, such as crushed rock, are typically type B soil.
Granular soils without cohesion, such as crushed rock, are typically type B soil.
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Type C soils are rated below 0.5 tsf (tons per square foot).
Type C soils are rated below 0.5 tsf (tons per square foot).
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Unconfined Compressive Strength is determined by:
Unconfined Compressive Strength is determined by:
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The error rate of the pocket penetrometer is between 20% and:
The error rate of the pocket penetrometer is between 20% and:
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After you complete the plasticity (wet thread) test, if soil sample does not break or tear, the soil is considered:
After you complete the plasticity (wet thread) test, if soil sample does not break or tear, the soil is considered:
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A common visual test is to:
A common visual test is to:
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Soil that crumbles freely or with moderate hand pressure into individual grains is granular, according to:
Soil that crumbles freely or with moderate hand pressure into individual grains is granular, according to:
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For trenching and excavations, a competent person must have knowledge of:
For trenching and excavations, a competent person must have knowledge of:
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Before excavating material, each of the following is true of underground utilities EXCEPT:
Before excavating material, each of the following is true of underground utilities EXCEPT:
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When using ladders for egress from a trench, they must:
When using ladders for egress from a trench, they must:
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In trenches, each of the following is true of accumulating water hazards EXCEPT:
In trenches, each of the following is true of accumulating water hazards EXCEPT:
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Unclassified soil is considered no better than which soil classification?
Unclassified soil is considered no better than which soil classification?
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Even if you are using a trench shield, all ejected spoils material still need to be at least ___ ft away from the edge of the slope at the top.
Even if you are using a trench shield, all ejected spoils material still need to be at least ___ ft away from the edge of the slope at the top.
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No major structural repairs may be performed on an excavation protective system without permission from the manufacturer or engineer.
No major structural repairs may be performed on an excavation protective system without permission from the manufacturer or engineer.
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Which conditions prevent soil from being classified as type A soil?
Which conditions prevent soil from being classified as type A soil?
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What is the minimum need to properly classify soil under the Construction OSHA Standard, Subpart P?
What is the minimum need to properly classify soil under the Construction OSHA Standard, Subpart P?
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Which of the following is specified by the construction OSHA standard, subpart P, sloping requirements for excavations?
Which of the following is specified by the construction OSHA standard, subpart P, sloping requirements for excavations?
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Assign a classification of type B to the soil. If you protect this excavation by sloping it, how wide is the excavation at the top?
Assign a classification of type B to the soil. If you protect this excavation by sloping it, how wide is the excavation at the top?
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You are excavating for a 24-inch water line. What is the soil type?
You are excavating for a 24-inch water line. What is the soil type?
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If you have a trench greater than 20 ft deep:
If you have a trench greater than 20 ft deep:
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In most cases, Type A soil can be sloped up to:
In most cases, Type A soil can be sloped up to:
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In most cases, Type C soil can be sloped up to:
In most cases, Type C soil can be sloped up to:
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One advantage to using shoring tables is not having to determine the soil type.
One advantage to using shoring tables is not having to determine the soil type.
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Selection of size and spacing of shoring members are based on height and width of trench.
Selection of size and spacing of shoring members are based on height and width of trench.
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Shoring is any mechanical system used to prevent collapse of an excavation.
Shoring is any mechanical system used to prevent collapse of an excavation.
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Which of the following variables is not considered in the timber shoring tables found in appendix C?
Which of the following variables is not considered in the timber shoring tables found in appendix C?
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Shoring is covered in the OSHA standards subpart P:
Shoring is covered in the OSHA standards subpart P:
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One advantage to using shoring tables is not having to determine the soil type.
One advantage to using shoring tables is not having to determine the soil type.
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When vertical shores are used, there must be a minimum of ___ shores spaced equally, horizontally, in a group.
When vertical shores are used, there must be a minimum of ___ shores spaced equally, horizontally, in a group.
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The decision whether to use sheeting with aluminum hydraulic shoring depends primarily on:
The decision whether to use sheeting with aluminum hydraulic shoring depends primarily on:
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Given Type A soil, dry conditions, and a 40-ton piece of equipment near the edge of the trench, what do we know?
Given Type A soil, dry conditions, and a 40-ton piece of equipment near the edge of the trench, what do we know?
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If you are using sheeting with aluminum hydraulic shoring, what do we know about the shores, or wales?
If you are using sheeting with aluminum hydraulic shoring, what do we know about the shores, or wales?
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Aluminum hydraulic shores are usually installed ____ in Type A soil.
Aluminum hydraulic shores are usually installed ____ in Type A soil.
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If using a trench box in combination with sloping or benching, the box should extend at least ___ above the adjacent slope.
If using a trench box in combination with sloping or benching, the box should extend at least ___ above the adjacent slope.
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Job-built trench boxes are never allowed in construction.
Job-built trench boxes are never allowed in construction.
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Earth excavation to a depth of ___ ft below the shield is permitted.
Earth excavation to a depth of ___ ft below the shield is permitted.
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When 'stacking' trench boxes:
When 'stacking' trench boxes:
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When using trench boxes, why is the space between the box and trench wall backfilled?
When using trench boxes, why is the space between the box and trench wall backfilled?
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Trench boxes don't prevent cave-ins, but do protect people.
Trench boxes don't prevent cave-ins, but do protect people.
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Unconfined compressed strength is the load at which a soil will fail.
Unconfined compressed strength is the load at which a soil will fail.
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Study Notes
Excavation Hazards & Soil Classifications
- A cubic yard of soil can weigh approximately 3,000 lbs, similar to a small pickup truck.
- Type A soil cannot be disturbed, part of a mixed layered system, subject to vibration, or seeping water.
- Air monitoring is required before entry in trenches deeper than 4 ft with potential hazards.
- Stable rock, classified as Types A and B, differs from Type C mainly in stability.
- Type B soil includes certain sandy soils, while Type C soils are those with low stability and cohesion, rated below 0.5 tsf.
Soil Testing & Classification
- Common soil classification tests include visual inspections and manual tests; testing is critical for determining soil type.
- Type A soils are generally clay and cemented soils like caliche and hardpan.
- Type B soils offer four options for protective measures, while Type C has the lowest angle of repose at 34 degrees.
Construction Safety & Protective Systems
- Protective systems, such as trench shields or boxes, are essential for minimizing risks during excavations.
- A competent person is responsible for inspecting excavations daily and must have the authority to correct hazards.
- Shoring systems can be custom-built using approved tabulated data, increasing excavation safety.
Safety Guidelines for Excavations
- Excavated materials should be kept at least 2 ft away from the edge of a trench.
- Walkways require handrails if 6 ft or more above ground level.
- Warning systems for mobile equipment can include barricades and hand signals to enhance safety at the site.
Regulations and Responsibilities
- The OSHA Soils Standard applies to excavation operations, excluding offshore petroleum drilling.
- Employers are responsible for following OSHA's excavation safety recommendations and ensuring safe working conditions.
- In cases of unstable soil or other hazards, a competent person must remove workers until safety precautions are implemented.
Hydration and Soil Conditions
- Water accumulation can severely compromise trench stability; shoring and sloping strategies must be employed to mitigate such risks.
- Both increases and decreases in moisture can affect soil stability, making careful monitoring vital.
Trench Construction Practices
- Aluminum hydraulic shoring can be installed without trench access, reducing the risk for workers.
- A minimum of three shores must be used when employing vertical shores for stability.
- Trench depth exceeding 20 ft mandates consultation with a registered professional engineer for safe excavation practices.
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Description
Test your knowledge on excavation hazards and soil classifications with these flashcards from the OSHA 30 course. Learn about soil weight, types, and safety requirements for trench entry. Perfect for those preparing for OSHA certification or working in construction environments.
