Modern technology for deep compaction

Modern technology for deep compaction from Ilmi Solutions Oy. Ilmi has developed new deep compaction hammer for deep compaction of filling areas and benches. Unlike traditional deep compaction methods, the Ilmi H7000 deep compaction hammer can be used to compact fillings built directly underwater without massive overbanks over water. It is also possible to deep compact the filling benches built on earth with the Ilmi H7000 deep compaction hammer.

The deep compaction hammer is a product developed entirely by Ilmi Solutions Oy. Ilmi has done its own work on hammer machine control and a real-time measurement and monitoring system. The energy control of the H7000 deep compaction lever is stepless and the maximum energy is 700 kNm (7 tn is dropped from 10 m).


  • Deep compacting of underwater embankments
  • Measured: drop energy, deflected/drop, position data with GPS
  • Small carbon footprint as avoids the construction and dismantling of unnecessary overbanks
  • Cost-effective, can be deep-sealed with a directly built embankment
  • Fully real-time computer-based monitoring and recording of the drop event
  • Hammer easy to use
  • Fast and safe method

The deep-tuning hammer has already successfully completed the first underwater embankment sealing work, and the work was completed nicely ahead of schedule.

  • The area to be sealed was 4000 m2
  • The thickness of the quarry fill ranged from 3 metres to 5 metres
  • The upper surface of the quarry filler was -4.9 metres below the water level at the start of the sealing

Location of the work site: Fennovoima nuclear power plant site in Pyhäjoki
Main contractor: BMGS
Deep compacting contractor: Drillmare Oy