耶馬溪層中に存する硬質粘土の性質について

概要

論文の詳細を見る
The authors tested characteristics of brown and white hard clay developed in state of vein in tuff breccia and tufferous andesite in Yabakei district, Oita Prefecture. The brown hard clay is natural unit weight r_t=1.89g/cm^3, moisture content w=34.9%, velocity of elastic wave V_p=2.2km/sec, V_s=0.8km/sec, and unconfined compressive strength q_u=14.5kg/cm^2, and it has characteristics similar to tertiary muddy soft rocks. But hair cracks are caused to dry it. The dried brown hard clay break down small pieces, 2 or 3 mm in dia., in a moment as it is soaked in water, and it occurs high expansive pressure. The hard clay is consisted of montmorillonite, halloysite, feldspar and other clay minerals according to X-ray analysis. It is considered that the hard clay is consisted of bad crystalline clay minerals, thinking of other analyses with X-ray analysis. The authors consider that the hard clay is producted by hydrothermal alternation under 50℃.
一般社団法人日本応用地質学会の論文
1975-03-30