AZ L-19 Excavating, Grading & Trenching
Contractor Exam Practice Questions
And Correct Answers (Verified Answers)
Plus Rationales 2027 Q&A | Instant
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1. What is the primary purpose of a site grading plan?
A. To determine the contractor's insurance premium
B. To establish finished elevations, slopes, drainage, and earthwork
requirements
C. To determine the number of workers required
D. To establish equipment fuel consumption
Answer: B. To establish finished elevations, slopes, drainage, and
earthwork requirements
Rationale: A grading plan provides the elevations and slopes needed to
properly shape the site and direct drainage while establishing the basis for
earthwork quantities.
, 2. Before beginning excavation on a construction site, what should be
done regarding existing underground utilities?
A. Assume utilities are located at least 10 feet deep
B. Begin excavation and locate utilities after they are exposed
C. Have underground utilities located and marked through the appropriate
notification process
D. Ask the equipment operator to watch for utility lines
Answer: C. Have underground utilities located and marked through the
appropriate notification process
Rationale: Underground utilities must be identified before excavation to
reduce the risk of striking gas, electrical, water, communication, or other
buried facilities.
3. What is the main purpose of compacting soil?
A. To increase its air content
B. To reduce its density
C. To increase soil strength and reduce settlement
D. To increase its moisture evaporation rate
Answer: C. To increase soil strength and reduce settlement
Rationale: Proper compaction reduces voids in soil, increases stability and
bearing capacity, and minimizes future settlement.
, 4. Which soil generally has the greatest cohesion?
A. Clean gravel
B. Clean sand
C. Clay
D. Crushed rock
Answer: C. Clay
Rationale: Clay particles are very small and exhibit significant cohesion due
to their particle characteristics and interaction with water.
5. What is the primary purpose of trench protective systems?
A. Increase production speed
B. Prevent workers from being buried by collapsing soil
C. Improve trench drainage only
D. Reduce equipment noise
Answer: B. Prevent workers from being buried by collapsing soil
Rationale: Protective systems such as sloping, benching, shoring, and
shielding are used to protect workers from cave-ins and related excavation
hazards.
6. Which of the following is an example of a trench shield?
, A. A concrete footing
B. A trench box
C. A retaining wall
D. A bulldozer blade
Answer: B. A trench box
Rationale: A trench box is designed to protect workers inside a trench by
shielding them from cave-in hazards.
7. What is the primary function of a trench shoring system?
A. Support the sides of the excavation
B. Increase the trench depth
C. Replace utility locating
D. Compact the trench bottom
Answer: A. Support the sides of the excavation
Rationale: Shoring systems are installed to support excavation walls and
help prevent soil movement or collapse.
8. Why should excavated material generally be kept away from the edge
of a trench?
A. It makes the soil wetter
B. It reduces the surcharge load and risk of material falling into the
Contractor Exam Practice Questions
And Correct Answers (Verified Answers)
Plus Rationales 2027 Q&A | Instant
Download Pdf
1. What is the primary purpose of a site grading plan?
A. To determine the contractor's insurance premium
B. To establish finished elevations, slopes, drainage, and earthwork
requirements
C. To determine the number of workers required
D. To establish equipment fuel consumption
Answer: B. To establish finished elevations, slopes, drainage, and
earthwork requirements
Rationale: A grading plan provides the elevations and slopes needed to
properly shape the site and direct drainage while establishing the basis for
earthwork quantities.
, 2. Before beginning excavation on a construction site, what should be
done regarding existing underground utilities?
A. Assume utilities are located at least 10 feet deep
B. Begin excavation and locate utilities after they are exposed
C. Have underground utilities located and marked through the appropriate
notification process
D. Ask the equipment operator to watch for utility lines
Answer: C. Have underground utilities located and marked through the
appropriate notification process
Rationale: Underground utilities must be identified before excavation to
reduce the risk of striking gas, electrical, water, communication, or other
buried facilities.
3. What is the main purpose of compacting soil?
A. To increase its air content
B. To reduce its density
C. To increase soil strength and reduce settlement
D. To increase its moisture evaporation rate
Answer: C. To increase soil strength and reduce settlement
Rationale: Proper compaction reduces voids in soil, increases stability and
bearing capacity, and minimizes future settlement.
, 4. Which soil generally has the greatest cohesion?
A. Clean gravel
B. Clean sand
C. Clay
D. Crushed rock
Answer: C. Clay
Rationale: Clay particles are very small and exhibit significant cohesion due
to their particle characteristics and interaction with water.
5. What is the primary purpose of trench protective systems?
A. Increase production speed
B. Prevent workers from being buried by collapsing soil
C. Improve trench drainage only
D. Reduce equipment noise
Answer: B. Prevent workers from being buried by collapsing soil
Rationale: Protective systems such as sloping, benching, shoring, and
shielding are used to protect workers from cave-ins and related excavation
hazards.
6. Which of the following is an example of a trench shield?
, A. A concrete footing
B. A trench box
C. A retaining wall
D. A bulldozer blade
Answer: B. A trench box
Rationale: A trench box is designed to protect workers inside a trench by
shielding them from cave-in hazards.
7. What is the primary function of a trench shoring system?
A. Support the sides of the excavation
B. Increase the trench depth
C. Replace utility locating
D. Compact the trench bottom
Answer: A. Support the sides of the excavation
Rationale: Shoring systems are installed to support excavation walls and
help prevent soil movement or collapse.
8. Why should excavated material generally be kept away from the edge
of a trench?
A. It makes the soil wetter
B. It reduces the surcharge load and risk of material falling into the
