General Contractor License Site Work and Excavation 2 — Questions and Answers
Question 1: What is the minimum required distance from the edge of an excavation that spoil piles must be placed to prevent cave-ins?
- 1 foot
- 2 feet (Correct answer)
- 3 feet
- 5 feet
Correct answer: 2 feet
OSHA requires spoil piles to be placed at least 2 feet from the edge of an excavation to reduce surcharge loads that could cause collapse.
Question 2: Which soil classification is considered the most stable for excavation purposes under OSHA standards?
- Type C
- Type B
- Type A (Correct answer)
- Unstable Rock
Correct answer: Type A
Type A soil is the most stable classification, having an unconfined compressive strength of 1.5 tons per square foot or greater.
Question 3: When performing dewatering operations during excavation, where should the discharge water be directed?
- Back into the excavation
- To a storm drain or approved discharge point away from the site (Correct answer)
- Along the perimeter of the excavation
- Into adjacent soil to recharge groundwater
Correct answer: To a storm drain or approved discharge point away from the site
Discharge water must be directed away from the excavation to an approved point to prevent saturation of the surrounding soil and potential cave-ins.
Question 4: What must a contractor do before beginning any excavation work in an area with unknown underground utilities?
- Begin excavating slowly with hand tools
- Call 811 (Dig Safe) to have utilities located and marked (Correct answer)
- Review old site drawings only
- Install ground-penetrating radar equipment
Correct answer: Call 811 (Dig Safe) to have utilities located and marked
Federal law requires calling 811 before digging to have underground utilities located and marked, preventing damage and injuries.
Question 5: A sloped excavation in Type B soil must not exceed a slope ratio of:
- ¾H:1V
- 1H:1V (Correct answer)
- 1½H:1V
- 2H:1V
Correct answer: 1H:1V
OSHA requires a maximum slope of 1H:1V (45 degrees) for Type B soils to provide adequate stability.
Question 6: Which equipment is most appropriate for cutting through rock during excavation when blasting is not permitted?
- Standard backhoe bucket
- Hydraulic hammer (hoe-ram) attachment (Correct answer)
- Clamshell bucket
- Dragline excavator
Correct answer: Hydraulic hammer (hoe-ram) attachment
A hydraulic hammer or hoe-ram attachment breaks rock mechanically and is used when explosives are not permitted or practical.
Question 7: What is the purpose of a 'shoring' system in an excavation?
- To pump water out of the excavation
- To support trench walls and prevent cave-ins (Correct answer)
- To compact the subgrade soil
- To grade the excavation bottom level
Correct answer: To support trench walls and prevent cave-ins
Shoring systems use structural members such as hydraulic shores or timber bracing to support trench walls and prevent collapse.
General Contractor License Site Work and Excavation 2
What is the minimum required distance from the edge of an excavation that spoil piles must be placed to prevent cave-ins?