A construction site has an excavation that is 8 feet deep in Type C soil. What is the maximum allowable slope ratio for the sides of this excavation?
Correct Answer
A) 1.5:1 (34 degrees)
For Type C soil (the least stable), OSHA requires a maximum slope of 1.5:1 or 34 degrees from horizontal. This provides adequate protection against cave-ins in unstable soil conditions.
Why This Is the Correct Answer
Type C soil is the least stable soil classification under OSHA standards, consisting of cohesive soil with an unconfined compressive strength of 0.5 tons per square foot or less. For excavations in Type C soil, OSHA 29 CFR 1926.652 specifically requires a maximum allowable slope of 1.5:1 (1.5 horizontal to 1 vertical) or 34 degrees from horizontal. This slope ratio provides adequate protection against cave-ins by creating a stable angle that accounts for the poor cohesive properties of Type C soil.
Why the Other Options Are Wrong
Option B: 0.75:1 (53 degrees)
A 0.75:1 slope (53 degrees) is much too steep for any soil type and would be extremely dangerous, creating an almost vertical cut that would likely result in immediate cave-in
Option C: 2:1 (26.5 degrees)
While a 2:1 slope would be safer than required, it's not the maximum allowable slope specified by OSHA regulations and would result in unnecessary excavation and increased costs
Option D: 1:1 (45 degrees)
A 1:1 slope (45 degrees) is too steep for Type C soil and would create an unsafe condition prone to cave-ins, as it doesn't account for the unstable nature of Type C soil
Memory Technique
Use 'ABC-123': Type A soil = 0.75:1, Type B soil = 1:1, Type C soil = 1.5:1 - each gets progressively more gradual as soil stability decreases
Reference Hint
OSHA 29 CFR 1926.652 - Requirements for protective systems, Table B-1 for maximum allowable slopes
More Project Mgmt Questions
What is the minimum R-value required for wall insulation in Florida Climate Zone 2?
A subcontractor brings a new chemical product to your jobsite. Under the Globally Harmonized System (GHS), what information must be immediately available to workers?
A construction site has a trench that is 8 feet deep in Type B soil. What is the maximum allowable slope ratio for the trench walls without protective systems?
What is the maximum recommended spacing between drywall screws when attaching to wood studs?
Your crew discovers suspected asbestos-containing materials during a renovation project. What is the first action you should take?
A scaffold platform is 12 feet long and 5 feet wide. If the maximum load capacity is 25 pounds per square foot, what is the total weight capacity of this platform?
Which CSI MasterFormat Division would contain specifications for fire-stopping and firesafing materials?
In tilt-up concrete construction, what is the primary advantage of this method over conventional cast-in-place construction?
Which OSHA standard specifically addresses construction industry safety and health regulations?
A structural drawing shows a beam labeled 'W12x26'. What does the '26' represent?
People Also Study
Business & Financial Management
120 questions · 70% to pass
Contract Administration
60 questions · 70% to pass