CHST Excavation and Trenching Safety 5

Question 1

What action must be taken before an excavation is entered each day or after a rainstorm?

Accepted Answer

Have a competent person inspect for hazardous conditions

Answer

OSHA 1926.651(k) requires a competent person to inspect excavations daily and after any event that could increase hazard potential, such as rain.

Question 2

Which shoring system uses vertical members (uprights) driven or placed against trench walls, held by walers and cross braces?

Accepted Answer

Timber shoring

Answer

Timber shoring uses vertical uprights, horizontal walers, and cross braces to support trench walls against collapse.

Question 3

Under what circumstance may workers enter an unprotected excavation less than 5 feet deep?

Accepted Answer

Only when a competent person determines there is no cave-in hazard

Answer

OSHA 1926.652(a) allows excavations under 5 feet to go unprotected only if a competent person examines the ground and finds no cave-in potential.

Question 4

Fissured soil discovered during excavation typically indicates what type of soil classification?

Accepted Answer

Type B or C depending on other factors

Answer

Fissured soil is excluded from Type A classification and may be Type B or Type C depending on its other properties and conditions.

Question 5

Which utility locating service must be contacted before excavation begins in the United States?

Accepted Answer

811 (Call Before You Dig)

Answer

Federal law requires contractors to contact 811 (the national call-before-you-dig number) to have underground utilities marked before any excavation.

CHST - Construction Health and Safety Technician Practice Test