Evaluation for compressibility of sand in impulsive loading triaxial test

Dynamic consolidation method for compacting base ground has been adopted on a various type of soils in the past decade. However, its theoretical evaluation has not been fully developed yet, because its mechanism of improvement is too complex. Impulsive loading triaxial test apparatus was developed in this study for the purpose of testing soil elements applying the stress increments induced by dropping hanmmer. Furthermore, a compressibility of sandy soil under various stress increments and drainage conditions were investigated by using the apparatus. As a result, at first, it was found that in the case of undrained tests, the compaction of soil was produced by dissipation of induced pore water pressure after undrained loading. Secondly, it was concluded that in the case of drained tests, the change of void ratio was induced by both increments of effective mean principal stress and deviator stress.