A trenching operation requires sloping in Type B soil. Calculate the maximum allowable slope ratio according to Cal/OSHA:
Correct Answer
A) 1:1 (horizontal to vertical)
Cal/OSHA Section 1541.1 requires Type B soil to be sloped at a maximum of 1:1 (45 degrees) for safe excavation without additional protective systems.
Why This Is the Correct Answer
Cal/OSHA Section 1541.1, Appendix B, classifies soil into Types A, B, and C and assigns maximum allowable slopes for each. Type B soil must be sloped at no steeper than 1H:1V (1 foot horizontal for every 1 foot vertical, i.e., 45°). This is less steep than Type A (¾H:1V) but steeper than Type C (1½H:1V), reflecting Type B's intermediate stability.
Why the Other Options Are Wrong
Option B: 3/4:1 (horizontal to vertical)
¾:1 (approximately 37°) is the maximum allowable slope for Type A soil—the most stable classification. Using a steeper slope in Type B soil would be unsafe and non-compliant because Type B is less cohesive than Type A.
Option C: 1/2:1 (horizontal to vertical)
½:1 is steeper than even Type A's allowance and is not a recognized maximum slope under the Cal/OSHA standard for any soil type. Using such a steep slope in Type B soil would create a serious cave-in hazard.
Option D: 1.5:1 (horizontal to vertical)
1.5:1 is the required slope for Type C soil—the least stable, most granular classification (e.g., gravel, submerged soil). Applying a Type C slope to Type B soil is unnecessarily conservative but would not comply with the question's requirement to use the Type B standard.
Memory Technique
Use the alphabet-to-slope mnemonic: A = ¾ (smallest, best soil), B = 1 (middle), C = 1½ (largest, worst soil). The slope ratio numerator increases by roughly ¾ with each letter step. Or think: 'Better soil, steeper cut.'
More California Questions
A construction site has employees working at heights of 12 feet above the ground on a steep-slope roof. According to Cal/OSHA fall protection requirements, what must be provided?
A construction crew is working outdoors in Fresno when the temperature reaches 97°F. Under Cal/OSHA heat illness prevention requirements, what is the minimum frequency for providing preventive cool-down rest periods?
A contractor is renovating a building built in 1975 and discovers material suspected to contain asbestos. According to Cal/OSHA regulations, what is the first required action?
Under Cal/OSHA regulations, what is the minimum frequency for reviewing and updating an Injury and Illness Prevention Program (IIPP)?
Calculate the minimum shade area required for 8 construction workers during a heat illness prevention cool-down period in California:
An employee working with lead-based paint removal has a blood lead level of 45 μg/dl. According to Cal/OSHA lead standards, what action must the employer take?
An IIPP must include procedures for investigating workplace accidents. According to Cal/OSHA, who is responsible for conducting these investigations?
A competent person inspecting a trench notices water seepage and minor soil movement. Under Cal/OSHA excavation standards, what action is required?
Calculate the required air changes per hour for a confined space with lead work under Cal/OSHA regulations. The space volume is 1,200 cubic feet and the exhaust fan moves 400 CFM. How many air changes per hour are being provided?
A roofing contractor is installing fall protection on a commercial building. Under Cal/OSHA Title 8, Section 1710, at what height does fall protection become mandatory for construction work?
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