11.6: Review Questions

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Multiple Choice Questions

1. Which of the following best describes the difference between an exaction and a trench?

(a) Excavations are deeper than trenches

(b) A trench is always less than 10 feet deep

(c) Excavations are any man-made cut in the earth, while a trench is a narrow exaction where depth is greater than width and the width is less than 15 feet

(d) Trenches are man-made while excavations occur naturally

2. Which of the following is not a potential hazard associated with trenching and excavation work?

(a) Cave-ins

(b) Hazardous atmospheres

(d) High noise levels

3. OSHA requires protection against cave-ins for excavations that are:

(a) 2 feet or deeper

(b) 4 feet or deeper

(d) 10 feet or deeper

4. Which soil type has the lowest compressive strength and is considered the least stable?

(a) Stable rock

(b) Type A

(d) Type C

5. A competent person at an excavation site is responsible for all of the following except:

(a) Classifying soil

(b) Designing structural ramps

(d) Operating excavation machinery

6. Which of the following protective systems involves using a shield placed between workers and trench walls?

(a) Sloping

(b) Benching

(d) Shielding

7. Materials (spoils) from an excavation must be kept at least how far from the edge?

(a) 6 inches

(b) 1 foot

(d) 5 feet

8. Which of the following best describes the role of a “competent person” at a trenching site?

(a) Supervises workers’ daily schedules

(b) Identifies hazards and has authority to correct them

(d) Approves construction blueprints

9. What is one of the main purposes of classifying soil before beginning an excavation?

(a) To determine the type of protective system required

(b) To estimate how long the project will take

(d) To decide which workers to assign to the site

10. Which action could create a hazard when working near an excavation?

(a) Keeping heavy equipment away from trench edges

(b) Testing for hazardous atmospheres

(d) Inspecting trenches after rainfall

11. Why should excavations be inspected after a rainstorm or water intrusion?

(a) Rain can cause soil conditions to change and increase cave-in risk

(b) Rain improves soil cohesion and stability

(d) Inspections after rain are optional

12. Which type of protective system involves cutting back trench walls to a safe angle?

(a) Shielding

(b) Shoring

(d) Benching

13. When should atmospheric testing be performed in an excavation?

(a) Only when workers report feeling ill

(b) Before each shift and whenever hazardous atmospheres might exist

(d) After work is completed

14. Why is it dangerous to work under suspended loads in an excavation area?

(a) It can reduce air circulation

(b) Loads may fall and strike workers

(d) It increases noise levels

True/False Questions

15. True/False: One cubic yard of soil can weigh as much as a car.

16. True/False: Employers are not required to provide cave-in protection for trenches made entirely in stable rock.

17. True/False: Atmospheric testing is only required for trenches deeper than 10 feet.

18. True/False: A competent person must inspect trenches daily, before each shift, and after hazard-increasing events.

19. True/False: Excavated materials can be placed directly at the edge of the trench if the soil is stable.

20. True/False: Workers must never work under suspended or raised loads on an excavation site.

21. True/False: Water accumulation in an excavation does not pose a significant hazard if workers are using protective equipment.

22. True/False: Employers should share safety and health program details with workers to emphasize their role in excavation site safety.

23. True/False: A trench less than 5 feet deep never requires protective systems.

24. True/False: It is acceptable to enter a trench containing standing water if the worker is wearing waterproof boots.

25. True/False: Atmospheric testing is required only when there is visible gas or vapor present.

Answer Key: 1) c, 2) d, 3) c, 4) d, 5) d, 6) d, 7) c, 8) b, 9) a, 10) c, 11) a, 12) c, 13) b, 14) b, 15) True, 16) True, 17) False, 18) True, 19) False, 20) True, 21) False, 22) True, 23) False, 24) False, 25) False.

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