Site Work and Excavation Flashcards
7 cards from real General Contractor License practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Site Work and Excavation flashcards as text
What is the purpose of a 'soldier pile and lagging' wall system in excavation support?
Answer: To retain soil using vertical steel H-piles with horizontal timber lagging inserted between them
Soldier pile and lagging walls use driven or drilled H-piles as the primary structural element with timber, concrete, or steel lagging placed between them to retain the soil.
A contractor must excavate within 18 inches of a gas line. What is the required excavation method?
Answer: Use hand tools (hand digging) or hydrovac (vacuum excavation) only
Within the tolerance zone (typically 18-24 inches) of a marked utility, only hand digging or hydrovac excavation is permitted to avoid striking the line.
What does a 'percolation test' (perc test) measure on a construction site?
Answer: The rate at which soil absorbs water, used for septic system design
A percolation test measures how quickly water drains through soil, which is required data for designing septic systems and certain drainage features.
Which method is used to verify that compacted fill meets specified density requirements?
Answer: Nuclear density gauge (Troxler gauge) or sand cone test compared to Proctor standard
Nuclear density gauges and sand cone tests measure in-place density, which is compared to the maximum density from Proctor testing to verify compaction specification compliance.
What is the term for the natural moisture content at which a particular soil can be most efficiently compacted?
Answer: Optimum moisture content (OMC)
Optimum moisture content is the water content at which a given soil achieves its maximum dry density when compacted, as determined by the Proctor compaction test.
During excavation, a worker notices tension cracks appearing parallel to the trench at ground level nearby. This indicates:
Answer: Imminent trench wall failure requiring immediate evacuation
Tension cracks parallel to a trench are a critical warning sign of impending wall failure; all workers must immediately exit the excavation and the area must be evaluated by a competent person.
What is the function of a 'trench box' (trench shield) compared to shoring?
Answer: It protects workers from cave-ins by providing a rigid box structure but does not support the trench walls
A trench box shields workers inside it from cave-ins but does not prevent the walls from moving — it is a protective system, not a support system like hydraulic shoring.