You're constructing a foundation on liquefiable soils identified in a California coastal area. The geotechnical report recommends deep foundations. Which option is most commonly specified?
Correct Answer
B) Drilled concrete piers extending to stable soil
Drilled concrete piers extending through liquefiable soil to stable bearing strata are the most common deep foundation solution for liquefiable soils in California coastal areas.
Why This Is the Correct Answer
Drilled concrete piers (also called drilled shafts or caissons) are the most commonly specified deep foundation solution for liquefiable soils in California coastal areas. These piers extend through the unstable, potentially liquefiable soil layers to reach stable bearing strata below. They provide reliable load transfer and resist lateral forces during seismic events when soil liquefaction occurs, making them the standard engineering solution for these challenging soil conditions.
Why the Other Options Are Wrong
Option A: Increased footing width with deeper embedment
Increased footing width with deeper embedment is a shallow foundation modification, not a deep foundation system. While it may improve bearing capacity in stable soils, it doesn't address the fundamental problem of liquefaction potential in the soil mass and won't reach stable bearing strata below the liquefiable zone.
Option C: Compacted aggregate pier (stone column) system
Compacted aggregate piers (stone columns) are primarily used for soil densification and improvement of bearing capacity in soft soils. While they can reduce liquefaction potential to some degree, they don't provide the same reliable load transfer to stable bearing strata as drilled concrete piers and are less commonly specified as the primary solution.
Option D: Chemical soil stabilization with lime injection
Chemical soil stabilization with lime injection is typically used for clay soils and expansive soil treatment, not for addressing liquefaction potential in sandy coastal soils. Lime stabilization doesn't provide the deep foundation support needed to transfer loads through liquefiable soil layers to stable bearing strata below.
Memory Technique
Think 'DRILL DOWN TO SAFETY' - when soil can liquefy, you must drill concrete piers down through the dangerous zone to reach stable soil below.
More ca-trade Questions
A contractor is installing shear walls in a residence located in Seismic Design Category D. The engineer's plans call for 15/32-inch structural sheathing with 8d nails at 6 inches on center at panel edges. The contractor wants to substitute 7/16-inch OSB with the same nailing. Is this substitution acceptable?
You are reviewing plans for a mixed-use building where the ground floor will house a restaurant with commercial kitchen equipment. The architect has specified standard residential electrical requirements throughout. What Title 24 compliance issue should you identify?
According to CBC seismic provisions, what is the concept behind the 'strong column, weak beam' design philosophy?
A residence in California has 2,800 sq ft of conditioned space. The HVAC system efficiency is 16 SEER. What is the approximate Title 24 compliance margin compared to the minimum 14 SEER requirement?
A contractor is installing a heat recovery ventilation (HRV) system to comply with Title 24. The system serves a 2,000 sq ft house with 3 bedrooms. What is the minimum required ventilation rate?
During construction of a basement in sandy soil conditions, you encounter groundwater at 4 feet below grade. The basement extends 8 feet below grade. What is the critical design consideration per CBC?
During a seismic retrofit project, you discover that existing concrete has a compressive strength of 2,200 psi. The engineer specifies new anchor bolts that require 2,500 psi minimum concrete strength. What is the most appropriate action?
What is the maximum allowable notch depth in a 2x10 floor joist per CBC requirements?
You're reviewing plans for a wood-framed structure in seismic design category D. The project calls for a shear wall with 15/32-inch structural sheathing and 8d nails spaced 6 inches on center at panel edges. What is the allowable shear value per the CBC?
What is the fundamental concept behind California's seismic design philosophy for buildings?
People Also Study
Business & Financial Management
120 questions · 70% to pass
Contract Administration
60 questions · 70% to pass
Project Management
60 questions · 70% to pass
Related Study Resources
Previous Question
A residential building in California has a floor area of 2,400 square feet with R-30 ceiling insulation and dual-pane windows. What is the maximum allowable fenestration area under Title 24 for Climate Zone 3?
Next Question
Title 24 requires fenestration products to meet specific performance criteria. What does the Solar Heat Gain Coefficient (SHGC) measure?