“TRENCHING 101: DON’T GET BURIED”
What is the PRIMARY purpose of an excavation protective system?
A. Make production faster
B. Protect employees from cave-ins
C. Reduce dust
D. Give the excavator operator something to work around
B. Protect employees from cave-ins
Which OSHA soil classification presents the GREATEST cave-in hazard?
A. Stable Rock
B. Type A
C. Type B
D. Type C
D. Type C
How often must a Competent Person inspect an excavation?
A. Once a week
B. When OSHA shows up
C. Daily, before each shift, and after hazard-increasing events
D. Whenever someone remembers
C. Daily, before each shift, and after hazard-increasing events
Which condition automatically disqualifies soil from being classified as Type A?
A. High moisture content
B. Unconfined compressive strength greater than 1.5 tsf
C. Previous disturbance or vibration
D. Clay composition
C. Previous disturbance or vibration
How far from the excavation edge must spoil piles be kept?
A. 6 inches — basically hanging over the edge
B. 1 foot
C. 2 feet
D. Wherever the excavator operator puts them
C. 2 feet
Which protective system is PROHIBITED in Type C soil?
A. Sloping
B. Shoring
C. Shielding
D. Benching
D. Benching
What is the PRIMARY responsibility of the Competent Person?
A. Operate the excavator
B. Handle payroll
C. Identify hazards, classify soil, inspect excavations, and take corrective action
D. Stand near the trench holding a clipboard
C. Identify hazards, classify soil, inspect excavations, and take corrective action
Which excavation condition requires atmospheric testing before entry?
A. Every excavation
B. Excavations deeper than 4 feet where a hazardous atmosphere may exist
C. Anything deeper than 2 feet
D. Only excavations where someone says, “It smells weird down there.”
B. Excavations deeper than 4 feet where a hazardous atmosphere may exist
Safe access and egress are required when an excavation reaches:
A. 3 feet deep
B. 4 feet deep or greater
C. 5 feet deep or greater
D. Only when somebody complains about climbing out
B. 4 feet deep or greater
Which protective system supports excavation walls to prevent movement?
A. Shielding
B. Benching
C. Shoring
D. Asking the dirt nicely not to move
Answer: C
Which condition increases the risk of an excavation collapse?
A. Spoils maintained 2 feet from the edge
B. Proper sloping
C. Water accumulation and nearby vibrations
D. Daily inspections
C. Water accumulation and nearby vibrations
A hazardous atmosphere has been identified inside an excavation. When may employees enter?
A. Once they put their hard hats on
B. When the supervisor says it’s okay
C. When appropriate controls, monitoring, and rescue equipment are provided
D. As long as two employees go together — because apparently two people can breathe bad air better than one
C. When appropriate controls, monitoring, and rescue equipment are provided
Employees should never travel more than _____ laterally to reach a ladder.
A. 10 feet
B. 20 feet
C. 25 feet
D. “Bro, the ladder is right over there.”
C. 25 feet
Which protective system protects employees but does NOT prevent the actual cave-in?
A. Sloping
B. Shoring
C. Shielding — Trench Box
D. Barricades
C. Shielding — Trench Box
Before digging near underground utilities, the employer must FIRST:
A. Start digging slowly and see what happens
B. Call 811 and verify utility locations
C. Dig test holes with the excavator
D. Ask someone who worked there last year
B. Call 811 and verify utility locations
OSHA allows an excavation to remain without a protective system ONLY when:
A. It is less than 10 feet deep
B. It is less than 5 feet deep regardless of conditions
C. It is entirely in stable rock, OR less than 5 feet deep with no cave-in hazard as determined by a Competent Person
D. The project manager signs off on it
C. It is entirely in stable rock, OR less than 5 feet deep with no cave-in hazard as determined by a Competent Person
A ladder used for excavation access must extend at least:
A. 1 foot above the landing
B. 2 feet above the landing
C. 3 feet above the landing surface
D. High enough that you can grab the very last rung and hope for the best
C. 3 feet above the landing surface
OSHA requires a protective system in excavations that are:
A. 4 feet or deeper
B. 5 feet or deeper unless exempted by a competent person
C. 6 feet or deeper
D. Only deep enough to scare the superintendent
B. 5 feet or deeper unless exempted by a competent person
When approaching a marked underground utility, its exact location should be determined using:
A. A large excavator bucket
B. Safe excavation methods such as hand digging or vacuum excavation
C. The paint marks and a good guess
D. Digging from both directions until somebody finds it
B. Safe excavation methods such as hand digging or vacuum excavation
Which statement BEST summarizes OSHA’s excavation safety philosophy?
A. Most cave-ins can't be prevented, so just work quickly.
B. Excavation safety depends on planning, soil classification, Competent Person oversight, and proper protective systems.
C. A trench box eliminates every excavation hazard.
D. Only deep trenches require safety planning.
B. Excavation safety depends on planning, soil classification, Competent Person oversight, and proper protective systems.