Abstract
Measurement of impact acceleration of ram, earth pressure and ram penetration of ground was carried out under a variety of ram mass, ram base area and drop height in a series of the laboratory compaction tests. The waveforms of ram acceleration for the cases where the ram mass per unit ram base area is the same show a similar form, although the waveform changes remarkably with changes of the ram mass and ram base area. The waveform has two peaks; the first one is considered to be dependent on the elastic behavior of the soil and second one on the plastic behavior. The former can be interpreted in respect of the ram momentum and later in respect of the kinetic energy of the ram.
