1. EXCAVATION AND TRENCHING
Module 3
EXCAVATION AND TRENCHING

2. What You Will Learn
Important facts about excavation and trenching
Important terms relating to excavation and trenching

3. What You Will Learn—continued
OSHA regulations relating to excavation and trenching
How to identify practices that protect you at an excavation site

4. What You Will Learn—continued
How to find hazards at work that could cause an excavation or trenching injury
How to identify behaviors that could cause injuries at an excavation site

5. Find the Excavation/Trenching Hazards
Photo courtesy of the Construction Safety Council

6. Did You Know?
About 1,000 workers get hurt every year by excavation cave-ins.
Of these, 140 cause permanent disability, 75 cause death.
The rate of deaths in excavation is 112% higher than the rate for general construction.

7. Did You Know? 38% of all excavation incidents are due to cave-ins.
Trenches tend to collapse very quickly, leaving no time to react.

8. Did You Know?
37% of all trenching incidents occur at depths of less than 5 feet.
Small construction projects of under $50,000 cause most of the cave-in deaths.

9. Terms
Excavation
Trench
Spoils
Cave-In
Confined Space
Soil Sample

10. Protection Systems Benching System Sloping System Shoring System
Shield System

11. Competent Person
A competent person is someone who is trained
and qualified to make decisions based on science and engineering.

12. Quiz Question #1
TRUE OR FALSE?
Because trenches are outdoors, it is not necessary to be concerned about hazardous air. The outdoor air will neutralize any bad air in the trench.

13. Quiz Question #1
FALSE
OSHA 29 CFR
When dusts, fumes, mists, vapors or gases are produced, they must be handled to prevent a hazardous situation in the trench .

14. Quiz Question #2
TRUE OR FALSE?
If you are working in a trench where there are only a few inches of water, you are permitted to work in the trench.

15. Quiz Question #2
FALSE
OSHA 29 CFR (h)(1)
Employees shall not work in a trench where water is standing or accumulating, unless there is a system to remove the water, or the employee uses a safety harness and lifeline.

16. Quiz Question #3
TRUE OR FALSE?
If an excavation needs a ramp for entering and exiting, anyone on the construction crew can be assigned to find a ramp and put it in place.

17. Quiz Question #3
FALSE
OSHA 29 CFR (c)(1)(i)
Structural ramps at excavations much be designed by a competent person and constructed in accordance with the design.

18. Quiz Question #4
TRUE OR FALSE?
When a construction crew digs for an excavation, it is okay to pile the dirt that is dug up (the spoils) right at the edge of the excavation.

19. Quiz Question #4
FALSE
OSHA 29 CFR (j)(2)
The spoils of an excavation must be kept at least two feet from the edge of the excavation.

20. Quiz Question #5
TRUE OR FALSE?
A competent person has the authority to evacuate an excavation site if that person believes the site is exposing employees to unsafe conditions such as a possible cave-in or hazardous air.

21. Quiz Question #5
TRUE
OSHA 29 CFR (k)(2)
The competent person has authority to evacuate an excavation site if it is exposing employees to unsafe conditions such as a possible cave-in or hazardous air.

22. What are Your Best Practices?
With spoil placement at excavations
With general work practices at excavations

23. The Worksite Analysis 1. Identify your work space.
2. Look for hazards.
3. Use a checklist to identify hazards.
4. Discuss problems and corrections with supervisor.

24. Excavation/Trenching Hazards—Case #1
Photo courtesy of the Construction Safety Council

25. Excavation/Trenching Hazards—Case #2
Photo courtesy of the Construction Safety Council

26. Excavation/Trenching Hazards—Case #3
Photo courtesy of Associated General Contractors of America

27. Excavation/Trenching Hazards—Case #4
Photo courtesy of Associated General Contractors of America

28. Concerns at Your Worksite
Give examples of how a worker’s behavior could create an excavation or trenching hazard.