Engineer approval is required for trench shoring designs exceeding what depth?

Engineer approval is required for trench shoring designs exceeding what depth?

• A. 4 feet deep
• B. a water line
• C. 50 feet in length
• D. 20 feet deep

Answer: (D)

The key idea is when a trench’s protective system must be reviewed by a professional engineer. Deeper trenches pose much greater cave-in and load risks, so beyond twenty feet the design needs certified calculations and validation to ensure it will withstand soil pressures, groundwater, and nearby loads. For trenches at or below twenty feet, standard protective-system designs—following accepted methods—typically don’t require engineering approval. The other options don’t fit because a depth of four feet is well below the threshold, a water line is not a depth, and the length of the trench isn’t what triggers engineering approval.

The key idea is when a trench’s protective system must be reviewed by a professional engineer. Deeper trenches pose much greater cave-in and load risks, so beyond twenty feet the design needs certified calculations and validation to ensure it will withstand soil pressures, groundwater, and nearby loads. For trenches at or below twenty feet, standard protective-system designs—following accepted methods—typically don’t require engineering approval. The other options don’t fit because a depth of four feet is well below the threshold, a water line is not a depth, and the length of the trench isn’t what triggers engineering approval.