Abstract
In this paper, the hardness of the aggregates (>0.4 cm in diameter) was examined for the Kuroboku soil, which is distributed in the Tokai region and regarded as a non volcanic ash soil. The hardness of samples was evaluated by the compression test. The main results obtained are as follows:
(1) The failure stress pc of aggregates increases with a decrease of moisture content ω, but it decreases when aggregates are dried severely. Larger aggregates having a higher porosity n which decreases with drying have a lower value of pc than for smaller aggregates.
(2) Aggregates with a natural structure are superior in hardness represented by pc with respect to the spheres of remoulded soil when w is larger than the plastic limit.
(3) The relationship between the failure energy ec and ω of aggregates has a similar tendency as the relationship between pc and ω.
(4). The relationship between the failure strain εc and w of aggegates varies with the range of ω. On the other hand, the εc of the spheres of remoulded soil decreases with drying.
