FCC FCC Site Work & Foundation Systems 2 — Questions and Answers
Question 1: What is the purpose of dewatering during excavation in Florida?
- To lower the water table temporarily so excavation and foundation work can be performed in dry conditions (Correct answer)
- To permanently redirect a stream away from the site
- To irrigate surrounding landscaping
- To test water quality on the site
Correct answer: To lower the water table temporarily so excavation and foundation work can be performed in dry conditions
Dewatering uses pumps or well-points to temporarily lower groundwater levels, allowing safe excavation and concrete placement in Florida's high water table environment.
Question 2: When is a deep foundation system such as driven piles or drilled piers required in Florida?
- When near-surface soils are too weak to support the structure's loads and a suitable bearing stratum lies deeper (Correct answer)
- Only when the structure exceeds 50 stories
- Whenever the site is located near a body of water
- Only for bridges, never for buildings
Correct answer: When near-surface soils are too weak to support the structure's loads and a suitable bearing stratum lies deeper
Deep foundations transfer structural loads through weak near-surface soils down to stronger bearing strata, which is often necessary in Florida due to loose sands or organic layers.
Question 3: What is 'differential settlement' and why is it a concern in Florida construction?
- Uneven settling of different parts of a structure, which can cause cracking and structural damage, common on variable Florida soils (Correct answer)
- The difference in cost between two foundation types
- The legal settlement of a construction dispute
- Controlled demolition of a structure in sections
Correct answer: Uneven settling of different parts of a structure, which can cause cracking and structural damage, common on variable Florida soils
Differential settlement occurs when parts of a foundation settle at different rates, placing stress on the structure; Florida's variable soils make this a common risk.
Question 4: Which OSHA standard governs excavation and trenching safety on construction sites?
- 29 CFR 1926 Subpart P (Correct answer)
- 29 CFR 1910.147
- 29 CFR 1926 Subpart M
- 29 CFR 1904
Correct answer: 29 CFR 1926 Subpart P
OSHA 29 CFR 1926 Subpart P covers excavation and trenching safety requirements, including sloping, shoring, and protective system requirements.
Question 5: What is the minimum depth at which OSHA requires a protective system (shoring, sloping, or trench box) for an excavation?
- 5 feet (Correct answer)
- 2 feet
- 10 feet
- 8 feet
Correct answer: 5 feet
OSHA requires a protective system for any excavation 5 feet or deeper in most soil types to prevent cave-in hazards.
Question 6: In Florida, a contractor performing site grading must ensure that drainage is directed:
- Away from the structure and toward approved drainage outlets (Correct answer)
- Toward the street curb regardless of slope
- Only into retention ponds, never toward the street
- Back under the slab for natural irrigation
Correct answer: Away from the structure and toward approved drainage outlets
Proper site grading directs stormwater away from the building to prevent foundation erosion, flooding, and moisture intrusion, channeling it to approved drainage systems.
FCC FCC Site Work & Foundation Systems 2
What is the purpose of dewatering during excavation in Florida?