On-line compaction control in deep vibratory compaction

Deep vibratory compaction (vibroflotation) is a method of ground improvement up to depths of 40 m. It has been successfully used since 1936. The major problem of this method is, that the process of compaction is not well understood, although it works very well. The methods of compaction control during the vibration are unreliably. The achieved compaction can only be verified after vibration. In this paper the development of the new monitoring and quality control system "Bauer-RDV-online" is presented. It is shown that information from the movement of the vibrator can be used as additional quality control and indicator for the degree of compaction. Such information can be analyzed directly during compaction and offers thereby the possibility of an "on-line compaction control". This is shown based on theoretical studies and recent results of successful full-scale tests in Germany.