Quiz 15 Excavations
True
Type C soil cannot be benched
True
Type C soil is the least stable soil
True
A 10-foot column of dirt could weigh up to 1,200 pounds
Manufacturer
Any modifications to shields must be approved by the
False
FIre is not considered a hazard associated with excavations
True
Shields may be used in combination with benching and shoring
True
A competent person is capable of identify existing and predictable hazards in surrounding or working conditions that are unsanitary, hazardous, or dangerous to employees, and has authorization to take prompt corrective measures
All of the above
A condition that contributes to a serious hazard during excavation operations includes
Trench
A narrow underground excavation that is deeper than it is wide and no wider than 15 feet (4.5 meters) is called a
Competent person
A(n) _______ is capable of identifying existing and predictable hazards in surroundings or working conditions that are unsanitary, hazardous, or dangerous to employees, and has authorization to take prompt corrective measures
20
All excavations over ______ feet in depth must be designed by a registered professional engineer
annual inspections by a competent person
All of the following are OSHA's most cited violations in excavations, except
True
Before excavation work can begin, it is necessary to determine the location of the utilities underground
False
Benching is allowed in Type C soil
True
Cave-ins pose the greatest risk and are much more likely than other excavation-related accidents to result in worker fatalities
Once per shift
Hydraulic shoring must be checked at least ______ for leaking hoses and/or cylinders, broken connections, cracked nipples, bent bases, or any other damaged or defective parts
False
Hydraulic shoring must be checked weekly for defective parts
A professional engineer
If it is determined to be unsuitable, all equipment must be removed from service until _______ approves it for use
True
Inspections must be made by a competent person after rainstorms and any other hazard-increasing occurrence.
False
It is permissible to enter an excavation to get a soil sample
120 lbs per cubic foot : Moist soil 85 lbs per cubic foot : Dry soil
Match the correct weight to the appropriate type of soil
Granular cohesion-less soils including angular gravel (similar to crushed rock), silt, silt loam, sandy loam, and, in some cases, silty clay loam and sandy clay : Type B This is the most stable soil type : Type A Cohesive soil with unconfined compressive strength of 0.5 tsf (48 kPa) or less : Type C A natural solid mineral matter that can be excavated with vertical sides and remain intact while exposed : Stable rock
Match the following definitions to the appropriate soil types
A technique that employs a specific angle of incline on the sides of the excavation : Sloping A structure that supports that sides of an excavation and protects against cave-ins : Shoring
Match the following definitions to their related statements as described in the Definitions section of this lesson.
Stable Rock : Vertical (90 degrees) Type A : 3/4:1 (53 degrees) Type B : 1:1 (45 degrees) Type C : 1 1/2:1 (34 degrees)
Match the following soil types to their maximum allowable slopes
The basic types of shoring : Timber and aluminum shoring Provides a critical safety advantage because workers do not have to enter the trench to install them : Aluminum hydraulic shoring This is the more expensive and difficult method of shoring : Timber shoring A structure that supports the sides of an excavation and which is designed to prevent cave-ins : Shoring
Match the following terms to their related statements
When creating a hazard to employees, these must be removed or supported as necessary to safeguard employees working in the area : Surface encumbrances Before excavation work can begin, it is necessary to determiine the location of these by safe and acceptable means : Underground utilities These must be designed by a competent person : Structural ramps and runways Employees exposed to this must be provded with high visibility and reflective vests or other suitable garments : Vehicular traffic
Matching the following items to their related statements
Professional engineer : This person approves the determination that the excavation poses no threat to adjacent structures or employees Competent person : All equipment and employees must be montiored by this person when water is accumulating
Math the following responsibilities to the related persons
5 to 15
Most accidents occur in trenches _____ feet deep
All of the above
OSHA requires that all excavations in which employees could potentially be exposed to cave-ins be protected by
False
Protective systems are selected and constructed by the employer, who is free to choose any design, regardless of required performance critieria
True
Sloping or benching for excavations greater than 20 feet deep must be designed by a registered professional engineer
All of the above
Soil cannot be Type A if it is:
2
Spoils and equipment must be set at least _____ feet back from the excavation.
True
Structural ramps and runways must be designed by a competent person
False
Structural ramps and runways must be designed by a qualified person
True
The primary types of protective systems are sloping, benching, shoring, and shielding
Maximum allowable slope
The steepest incline of an excavation face that is acceptable for the most favorable site conditions as protection against cave-ins and is express as the ratio of horizontal distance to vertical rise is called
False
Walkways over excavations must conform to OSHA standards with guardrails over 12 feet.
Both a) and b)
Which of the following is required for protective system equipment?
Type C
What type of soil cannot be benched
4
Where oxygen deficiency (atmospheres containing less than 19.5% oxygen) exists or could reasonable be expected to exist, the atmospheres in the excavation must be tested before employees enter excavations great than ______ in depth
All of the above
Which of the following are OSHA standards for excavations?
Cave-ins
______ are the deadliest excavation hazards