If trench walls are too loose or soft for shoring, the walls must be sloped a minimum of:

If trench walls are too loose or soft for shoring, the walls must be sloped a minimum of:

• A. 1/2 : 1
• B. 1 : 1
• C. 3/4 : 1
• D. 2 : 1

Answer: (C)

When trench walls aren’t supported, you rely on the wall angle to keep the trench from caving in. In very loose or soft soil, the walls must be sloped to a safe, gentler angle to reduce the potential for failure. The required minimum is 3/4 horizontal to 1 vertical, meaning for every vertical foot of depth, the wall must extend outward at least 0.75 feet. This orientation helps lower the earth pressure on the wall and improves stability. If the soil is even looser, you may need an even gentler slope or an alternate protective system.

When trench walls aren’t supported, you rely on the wall angle to keep the trench from caving in. In very loose or soft soil, the walls must be sloped to a safe, gentler angle to reduce the potential for failure. The required minimum is 3/4 horizontal to 1 vertical, meaning for every vertical foot of depth, the wall must extend outward at least 0.75 feet. This orientation helps lower the earth pressure on the wall and improves stability. If the soil is even looser, you may need an even gentler slope or an alternate protective system.