What must be considered to ensure stability when performing cut-and-fill operations?

What must be considered to ensure stability when performing cut-and-fill operations?

• A. Only the color of soil
• B. The weather forecast only
• C. Proper cross-slope, compaction, material properties, and drainage.
• D. The type of vehicles used

Answer: (C)

Stability in cut-and-fill comes from controlling how the soil behaves under load and how water moves through it. When you cut into a slope and bring in fill, you create potential failure surfaces, so you must address several interrelated factors that determine strength and drainage. Proper cross-slope helps water drain away and prevents water from pooling in the cut or fill areas, which reduces erosion and the risk of slides. Compaction increases density, which improves shear strength and reduces settlement and voids that could lead to instability. Material properties, including shear strength, moisture content, and how the soil behaves under load (cohesion and internal friction), dictate how the soil will support loads without failing. Adequate drainage controls pore water pressure, which can dramatically reduce soil strength if water is trapped and pressures rise. The other choices don’t address these real stability factors. The color of soil doesn’t indicate its stability or strength, the weather forecast affects planning more than actual slope stability, and the type of vehicles used doesn’t determine the slope’s ability to stay stable.

Stability in cut-and-fill comes from controlling how the soil behaves under load and how water moves through it. When you cut into a slope and bring in fill, you create potential failure surfaces, so you must address several interrelated factors that determine strength and drainage.

Proper cross-slope helps water drain away and prevents water from pooling in the cut or fill areas, which reduces erosion and the risk of slides. Compaction increases density, which improves shear strength and reduces settlement and voids that could lead to instability. Material properties, including shear strength, moisture content, and how the soil behaves under load (cohesion and internal friction), dictate how the soil will support loads without failing. Adequate drainage controls pore water pressure, which can dramatically reduce soil strength if water is trapped and pressures rise.

The other choices don’t address these real stability factors. The color of soil doesn’t indicate its stability or strength, the weather forecast affects planning more than actual slope stability, and the type of vehicles used doesn’t determine the slope’s ability to stay stable.