Methods and apparatuses for compacting soil and granular materials

A method of densifying and compacting granular materials, the method comprising:

• a. providing a compaction apparatus comprising a drive shaft, a compaction chamber at a lower end of the drive shaft, and one or more diametric expansion elements, wherein the apparatus further comprises an opening in an upper surface of the compaction chamber comprising a flow-through passage exterior of the drive shaft and configured for accepting granular materials from outside of the drive shaft;
• b. driving the compaction apparatus into free-field soils to a specified depth;
• c. lifting the compaction apparatus a specified distance such that the one or more diametric restriction elements move downward relative to the compaction apparatus to hang from connections to the compaction apparatus thereby allowing granular materials located above a top portion of the compaction chamber to flow through the flow-through passage;
• d. re-driving the apparatus downwardly into the free-field soils causing the one or more diametric restriction elements to bunch-up forming compaction surfaces;
• and
• e. repeating the driving and lifting of the compaction apparatus.