A tamping foot compactor compacts coil from the bottom of the lift to the top.

A tamping foot compactor compacts coil from the bottom of the lift to the top.

• A. It compacts from bottom to top
• B. It compacts from top to bottom
• C. It only compacts the surface
• D. It does not compact soil

Answer: (A)

Bottom-to-top densification is how a tamping-foot compactor achieves uniform density. The tamping action drives soil particles together from the bottom of the lift, creating a solid base that the upper portion can compact against as you progress upward. If you started at the top, the lower part of the lift might remain underdense, and the weight of the material above can hinder deeper compaction, leaving voids and uneven density. This tool does actively compact soil, not just the surface, so controlling lift thickness and the direction of compaction ensures the entire layer is properly compacted.

Bottom-to-top densification is how a tamping-foot compactor achieves uniform density. The tamping action drives soil particles together from the bottom of the lift, creating a solid base that the upper portion can compact against as you progress upward. If you started at the top, the lower part of the lift might remain underdense, and the weight of the material above can hinder deeper compaction, leaving voids and uneven density. This tool does actively compact soil, not just the surface, so controlling lift thickness and the direction of compaction ensures the entire layer is properly compacted.