Why is soil compaction performed in embankment construction?

Why is soil compaction performed in embankment construction?

• A. To increase permeability
• B. To decrease density
• C. To increase strength and stability
• D. To reduce moisture

Answer: (C)

Compaction densifies the soil in an embankment. When the soil is packed tighter, there are fewer voids, more particle contact, and higher friction between grains. That increased density translates into greater shear strength and bearing capacity, which keeps the embankment stable under loads and resistive to settlement and sliding. Moisture is controlled to an optimum level to achieve maximum density, so compaction isn’t meant to reduce moisture itself. Increasing permeability would weaken the fill, and decreasing density would defeat what compaction accomplishes, so the primary goal is to boost strength and stability.

Compaction densifies the soil in an embankment. When the soil is packed tighter, there are fewer voids, more particle contact, and higher friction between grains. That increased density translates into greater shear strength and bearing capacity, which keeps the embankment stable under loads and resistive to settlement and sliding. Moisture is controlled to an optimum level to achieve maximum density, so compaction isn’t meant to reduce moisture itself. Increasing permeability would weaken the fill, and decreasing density would defeat what compaction accomplishes, so the primary goal is to boost strength and stability.