CHST CHST - Construction Health and Safety Technician Excavation and Trenching Safety Questions and Answers 3

Question 1

Under OSHA 29 CFR 1926.652, what is the maximum allowable slope for Type C soil when using the sloping method of protection?

Accepted Answer

1.5H:1V (34°)

Answer

Type C soil, the least stable classification, requires a slope of 1.5H:1V (approximately 34 degrees from horizontal).

Question 2

A competent person inspects an excavation after a rainstorm. What is the MOST important action if the walls show signs of tension cracking?

Accepted Answer

Remove all workers and reassess protective systems

Answer

Tension cracks are a warning sign of imminent collapse; all workers must be removed until a competent person determines the excavation is safe.

Question 3

What is the minimum distance that excavated spoil (dirt) must be kept from the edge of a trench?

Accepted Answer

2 feet

Answer

OSHA 29 CFR 1926.651(j)(2) requires excavated material to be kept at least 2 feet from the edge of a trench to prevent cave-in surcharge loading.

Question 4

Which condition would cause a competent person to reclassify soil from Type B to Type C?

Accepted Answer

Water seeping into the excavation from the sides

Answer

Fissured soil or soil from which water is seeping must be classified as Type C under OSHA Appendix B to Subpart P.

Question 5

When using a hydraulic shoring system, what step must occur BEFORE workers enter the trench?

Accepted Answer

Install and extend all hydraulic cylinders to rated capacity

Answer

Hydraulic cylinders must be installed and pressurized to their rated capacity before workers enter to ensure the system provides adequate lateral support.

CHST - Construction Health and Safety Technician Practice Test

CHST - Construction Health and Safety Technician Practice Test

CHST CHST - Construction Health and Safety Technician Excavation and Trenching Safety Questions and Answers 3