ABSTRACT
When set in motion, the eccentric weight rotates around its vertical axis and causes horizontal vibrations that are needed for the vibro compaction method. The dynamic horizontal forces are thus applied directly to the surrounding soil through the tubular casing of the vibrator, with the machine output remaining constant regardless of the depth of penetration; this is the key factor distinguishing vibro compaction from other methods employing vibratory hammers with their vertical vibrations. Specialist contractors have developed vibrators capable of compacting granular soils using frequencies as low as 25–30 Hz. Occasionally, the accompanying reduction of centrifugal force with frequency was found to be advantageous in optimizing the compaction effect. It is hoped that the findings of newer research work to better understand the complexity of the compaction of granular soil will eventually help to further modernize this technology particularly by obtaining information on the compaction process achieved directly from certain vibrator parameters measured during compaction.
