気乾状態と湿潤状態での田下凝灰岩ならびに大谷凝灰岩の一軸圧縮クリープ

抄録

It is well known that strength of rock decreases with moisture content. However, very limited data are available concerning the effect of moisture on time-dependent behaviour of rock. Therefore, a series of uniaxial compression creep tests were carried out under air-dried and water-saturated conditions. It was found that;
(1) Life time is proportional to exp {δ(σ_F-σ_c)}, where δ is a material constant and does not depend on moisture content.
(2) Primary creep follows the logarithmic creep law under both air-dried and water-saturated conditions.
(3) In the tertiary creep region, the strain rate under both conditions is inversely proportional to residual life.
In a recent paper, authors proposed a constitutive equation based on the uniaxial compression tests under various strain rates. In this study, creep tests were numerically simulated by the proposed constitutive equation. The results of computer simulation reveal that the constitutive equation can be applied not only to constant strain rate tests but also creep tests. For example, the calculated creep strain-rate vs. elapsed time curve coincides well with the experimental one.