Direct Power Compaction

Direct Power Compaction (DPC) is an efficient and highly economical technique for densifying loose sandy soils. In the procedure, H-piles are driven in the ground using a combination of downward and vibratory force to move particles of the sandy soil closer together and reduce the voids between them. Subsequent backfilling and vibration at the H-pile sites achieves the highest density possible.


Using H-piles, vibratory energy is delivered directly into the ground. The typical configuration is a quadruple axial DPC rig with a vibro-hammer at the top of each pile. The extent of the treatment required for optimal densification depends on the fines content and grain size/geometry of the soil being compacted. The best results are realized in sandy soils with low fines content (see Table 1, below). For loose sands/granular soils, the DPC method yields results equivalent to those of other densification/compaction methods, but the simplicity and speed of the DPC method makes it the most efficient and economical solution for improvement of sandy soils.


  • DPC densifies sandy soils both above & below the GWT to greater depths than dynamic compaction.
  • DPC is ideal for densification of reclaimed fills (dredge spoils).
  • DPC is an efficient and economical process with a proven track record.
  • Well established QA/QC leads to high quality, consistent results.