Trenching & Excavation Safety
Specialist Practice Exam 100 Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
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1. What is the minimum depth at which a trench requires a protective
system?
A. 3 feet
B. 4 feet
C. 5 feet
D. 6 feet
Rationale: OSHA requires protective systems for trenches 5 feet or deeper
unless made entirely in stable rock.
2. A competent person must inspect excavations and adjacent areas:
,A. Monthly
B. Weekly
C. Biweekly
D. Daily and as needed after conditions change
Rationale: Inspections must occur daily and after any condition changes
like rain or vibrations.
3. What is the primary hazard associated with trenching?
A. Heat exposure
B. Cave-ins
C. Noise
D. Falling objects
Rationale: Cave-ins are the leading cause of fatalities in trenching
operations.
4. How far back must spoil piles be kept from the trench edge?
A. 1 foot
B. 3 feet
C. 2 feet
D. 6 feet
Rationale: OSHA requires spoil and heavy equipment to be at least 2 feet
from trench edges.
,5. Which soil type is the most stable?
A. Type C
B. Type A
C. Type B
D. Type D
Rationale: Type A is the most stable soil classification under OSHA.
6. Benching is NOT allowed in which soil type?
A. Type A
B. Type B
C. Type C
D. Type B-1
Rationale: Type C soils are too unstable for benching methods.
7. Which of the following is considered a trench?
A. Excavation wider than it is deep
B. Excavation with sloped walls
C. Narrow excavation deeper than it is wide
D. Any hole over 3 feet deep
Rationale: A trench is defined as a narrow excavation where the depth is
greater than the width.
, 8. What is the maximum allowable slope for Type B soil?
A. 1:1
B. 1:1.5
C. 1:2
D. 2:1
Rationale: OSHA specifies a 1:1.5 (34°) slope for Type B soil.
9. Ladders used for access in trenches must extend above the trench edge
by:
A. 1 foot
B. 2 feet
C. 3 feet
D. 4 feet
Rationale: Ladders must extend at least 3 feet above the landing surface.
10. Access/egress must be provided at intervals of:
A. 15 feet
B. 25 feet
C. 50 feet
D. 75 feet
Specialist Practice Exam 100 Questions
And Correct Answers (Verified Answers)
Plus Rationales 2026 Q&A | Instant
Download Pdf
1. What is the minimum depth at which a trench requires a protective
system?
A. 3 feet
B. 4 feet
C. 5 feet
D. 6 feet
Rationale: OSHA requires protective systems for trenches 5 feet or deeper
unless made entirely in stable rock.
2. A competent person must inspect excavations and adjacent areas:
,A. Monthly
B. Weekly
C. Biweekly
D. Daily and as needed after conditions change
Rationale: Inspections must occur daily and after any condition changes
like rain or vibrations.
3. What is the primary hazard associated with trenching?
A. Heat exposure
B. Cave-ins
C. Noise
D. Falling objects
Rationale: Cave-ins are the leading cause of fatalities in trenching
operations.
4. How far back must spoil piles be kept from the trench edge?
A. 1 foot
B. 3 feet
C. 2 feet
D. 6 feet
Rationale: OSHA requires spoil and heavy equipment to be at least 2 feet
from trench edges.
,5. Which soil type is the most stable?
A. Type C
B. Type A
C. Type B
D. Type D
Rationale: Type A is the most stable soil classification under OSHA.
6. Benching is NOT allowed in which soil type?
A. Type A
B. Type B
C. Type C
D. Type B-1
Rationale: Type C soils are too unstable for benching methods.
7. Which of the following is considered a trench?
A. Excavation wider than it is deep
B. Excavation with sloped walls
C. Narrow excavation deeper than it is wide
D. Any hole over 3 feet deep
Rationale: A trench is defined as a narrow excavation where the depth is
greater than the width.
, 8. What is the maximum allowable slope for Type B soil?
A. 1:1
B. 1:1.5
C. 1:2
D. 2:1
Rationale: OSHA specifies a 1:1.5 (34°) slope for Type B soil.
9. Ladders used for access in trenches must extend above the trench edge
by:
A. 1 foot
B. 2 feet
C. 3 feet
D. 4 feet
Rationale: Ladders must extend at least 3 feet above the landing surface.
10. Access/egress must be provided at intervals of:
A. 15 feet
B. 25 feet
C. 50 feet
D. 75 feet
