A trench is being excavated in Type B soil. What is the maximum allowable slope ratio under Cal/OSHA regulations?
Correct Answer
D) 1:1 (horizontal to vertical)
For Type B soil, Cal/OSHA allows a maximum slope of 1:1 (45 degrees) or one horizontal to one vertical.
Why This Is the Correct Answer
Type B soil is classified as medium-stability soil (cohesive soils with an unconfined compressive strength between 0.5 and 1.5 tsf, or fissured soil, or granular cohesionless soil). Cal/OSHA, aligned with federal OSHA 29 CFR 1926 Subpart P, mandates a maximum slope of 1:1 (horizontal to vertical), which equals 45 degrees. This slope provides adequate stability for Type B conditions without requiring shoring.
Why the Other Options Are Wrong
Option A: 1.5:1 (horizontal to vertical)
1.5:1 (horizontal to vertical) is the required slope for Type C soil β the least stable classification (unconfined compressive strength less than 0.5 tsf, submerged soil, or soil subject to water seepage). Applying a Type C slope to Type B soil would be unnecessarily conservative but is not the correct answer for Type B.
Option B: 1/2:1 (horizontal to vertical)
1/2:1 (horizontal to vertical) is the slope permitted for Type A soil β the most stable classification (cohesive soil with unconfined compressive strength of 1.5 tsf or greater, undisturbed). This is a steeper cut and would be unsafe for the less-stable Type B soil.
Option C: 3/4:1 (horizontal to vertical)
3/4:1 (horizontal to vertical) is not a standard Cal/OSHA slope ratio for any soil classification. The three recognized ratios are 1/2:1 (Type A), 1:1 (Type B), and 1.5:1 (Type C). This option is a distractor.
Memory Technique
Use the mnemonic 'A-B-C slopes go 0.5, 1, 1.5' β each soil type adds half a unit of horizontal distance. Type A = 1/2 horizontal, Type B = 1 horizontal, Type C = 1.5 horizontal (all per 1 vertical foot).
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 97Β°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 ΞΌg/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 Β· 70% to pass
Contract Administration
60 questions Β· 70% to pass
Project Management
60 questions Β· 70% to pass
Related Study Resources
Previous Question
A worker on a residential roof installation is working 8 feet above the ground. According to Cal/OSHA fall protection requirements, what must the contractor provide?
Next Question
According to Cal/OSHA heat illness prevention requirements, shade structures must be open to air on how many sides?