A new method is proposed to estimate the effect of the heavy tamping on the compaction of a coral mixed soil and its valjdity is investigated in the field experiment.
　The proposed method consists of both dynamic response analysis and laboratory dynamic compaction test. The dynamic response of the soil deposit to the heavy tamping is analysed by using the three dimensional finite difference method and the visco-elastic model (voigt model). The analysis gives the distribution of the energy density propagating into the soil deposit due to the heavy tamping. The effect of the heavy tamping on the compaction of the soil deposit is estimated by intorducing the relationship between the soil density increment and the applied energy density to the soil element, which is obtained from the laboratory dynamic compaction test.
　The validity of the proposed method is confiemed in the field experiment, and both proposed method and field experiement indicate that the heavy tamping is valid for the compaction of the shallower depth of the soil deposit.