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D. Adam, H. Brandl, F. Kopf, I. Paulmichl:
"Heavy tamping integarted dynamic compaction control";
Keynote Lecture: 6th International Conference on Ground Improvement Techniques, Coimbra, Portugal; 2005-07-18 - 2005-07-19; in: "Proceedings of the 6th International Conference on Ground Improvement Techniques", University of Coimbra, (2005), ISBN: 9810535457; 1 - 8.

Heavy tamping is a deep dynamic compaction technique and has been increasingly used since beginning of the Seventies. The paper reports on in situ measurements and theoretical investigations referring to the decay of free soil vibrations caused by the falling weight after each impact. This behaviour is significant for the respective soil - falling mass interaction and enables a site-specific optimisation of the heavy tamping technique. The field tests comprised acceleration measurements of the falling mass and the soil whereby the falling height was changed repeatedly. The decay of the amplitudes of free vibrations provided a damping coefficient and a damped natural frequency, which are used to determine the Poisson´s ratio and the E-modulus of the ground after each impact from numerical calculations. Scope of the research project was to gain a reliable indicator for the compaction degree of the soil immediately after each impact, hence a method for compaction control and documentation.