fy08_SH-17041-08_03pp-module3-excavation-trenching2008-2.ppt

Excavation

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Module 3
EXCAVATION AND TRENCHING

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

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

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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

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

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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.

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

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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.

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Terms
►Excavation
►Trench
►Spoils
►Cave-In
►Confined Space
►Soil Sample

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Protection Systems
►Benching System
►Sloping System
►Shoring System
►Shield System

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

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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.

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Quiz Question #1
When dusts, fumes, mists, vapors
or gases are produced, they must
be handled to prevent a hazardous
situation in the trench .
FALSE
OSHA 29 CFR 1926.57

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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.

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Quiz Question #2
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.
FALSE
OSHA 29 CFR 1926.651(h)(1)

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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.

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Quiz Question #3
Structural ramps at excavations
much be designed by a competent
person and constructed in
accordance with the design.
FALSE
OSHA 29 CFR 1926.651(c)(1)(i)

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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.

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Quiz Question #4
The spoils of an excavation must be
kept at least two feet from the edge
of the excavation.
FALSE
OSHA 29 CFR 1926.651(j)(2)

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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.

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Quiz Question #5
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.
TRUE
OSHA 29 CFR 1926.651(k)(2)

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

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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.

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

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

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

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

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