特殊土壌の膨脹収縮について

概要

論文の詳細を見る
1. "Special Soil", as they call it, in the south Kyushu district has various new volcanic ejecta heaped up 1-10m in thickness on the ground-surface of "Shirasu" layer, and each physical property is different. Especially the situation of expansion and contraction is different according to the increase and decrease of its amount of water content. The result of my experiment is as shown before in Fig. 1-Fig. 4. 2. The proportion of expansion and contraction is different not only with the kind of soil, but also with the district and the depth in which the soil lies, and also with the direction (vertical & horizontal). 3. Expansion and contraction is generally reversible as a rule. But in the present experiment the soil whose expansion is great is mean in its contraction and the soil whose contraction is great is mean in its expansion. The soil once expanded does not contract to the original size. The soil once contracted does not expand to the original size. We see this instance most remarkably in the case of "Shirasu" : its expansion is great and its contraction mean. 4. The theoretical explanation of these phenomena is not complete yet and we expect it in future to be well explained. But it is considered now one of the reasons that the extreme disaster in "Shirasu" zone lies in the different condition of expansion and contraction of heaped up layer by water, even in the same place, as was mentioned above.
鹿児島大学の論文
1953-12-25