OSHA Subpart P, Appendix B requires that an excavation in Type A soil that is open less than 24 hours and is 12 feet or less in depth to have a maximum allowable slope of what?

OSHA Subpart P, Appendix B requires that an excavation in Type A soil that is open less than 24 hours and is 12 feet or less in depth to have a maximum allowable slope of what?

• A. 1/2:1
• B. 1:1
• C. 2:1
• D. 3:1

Answer: (A)

OSHA’s slope limits for excavations are determined by soil type, depth, and how long the trench will be open. For Type A soil, which is the most stable category, shorter exposure and shallower depth allow the steepest face. When the trench is open for less than 24 hours and is 12 feet or less deep, the maximum allowable slope is 1/2:1. That means for every vertical foot of depth, only 0.5 foot of horizontal run is allowed—the trench face can be quite steep, but not vertical. If the trench were deeper or left open longer, the slope would have to be flatter or protected with shoring or shielding.

OSHA’s slope limits for excavations are determined by soil type, depth, and how long the trench will be open. For Type A soil, which is the most stable category, shorter exposure and shallower depth allow the steepest face. When the trench is open for less than 24 hours and is 12 feet or less deep, the maximum allowable slope is 1/2:1. That means for every vertical foot of depth, only 0.5 foot of horizontal run is allowed—the trench face can be quite steep, but not vertical. If the trench were deeper or left open longer, the slope would have to be flatter or protected with shoring or shielding.