What equipment is suitable for compacting all fine-grained soils, but generally not suitable for use on cohesionless granular soils?

What equipment is suitable for compacting all fine-grained soils, but generally not suitable for use on cohesionless granular soils?

• A. Pneumatic Roller
• B. Tamping Foot Compactor
• C. Smooth-Drum Roller
• D. Vibratory Plate

Answer: (B)

The situation tests which type of compaction energy best suits soil texture. Fine-grained soils (clay and silt) compact well when the soil is kneaded and pore water is expelled, and a tamping foot compactor delivers repeated vertical impacts with a narrow foot to rearrange particles and consolidate the mass. This kneading action is highly effective for cohesive, fine-grained soils but not for cohesionless granular soils, where large grains and free drainage don’t respond well to localized impacts. In granular soils, energy is more effective when spread and transmitted through the soil mass via vibration or broader contact, which is why vibratory rollers or plates are generally preferred for those soils. So, the tamping foot compactor is ideal for all fine-grained soils but tends to perform poorly on cohesionless granular soils.

The situation tests which type of compaction energy best suits soil texture. Fine-grained soils (clay and silt) compact well when the soil is kneaded and pore water is expelled, and a tamping foot compactor delivers repeated vertical impacts with a narrow foot to rearrange particles and consolidate the mass. This kneading action is highly effective for cohesive, fine-grained soils but not for cohesionless granular soils, where large grains and free drainage don’t respond well to localized impacts. In granular soils, energy is more effective when spread and transmitted through the soil mass via vibration or broader contact, which is why vibratory rollers or plates are generally preferred for those soils. So, the tamping foot compactor is ideal for all fine-grained soils but tends to perform poorly on cohesionless granular soils.