ABSTRACT
In order to prevent ground disasters on volcanic soils, the mechanical properties have to be cleared in detail. In this study, the mechanical characteristics of a volcanic soil which have deposited in Japan were investigated by a series of laboratory tests. The arrangements of soil particles of the compacted specimens were also observed with a microscope. Based on the test results, the effects of compaction condition such as the difference of water content on the undrained strength was discussed. From the results of cross-sectional observation, it was found that the trends of arrangements of soil particles were influenced by the water contents at compaction work. Finally, the undisturbed specimens were sampled on site of slope failure. The undrained strength and soil structure were also discussed in this study.
