岩石の強度とクリープ寿命の分布特性に関する一考察

1.はじめに

2.理論的な背景

 2.1 確定論(構成方程式の定数)

 2.2 確率過程論(2状態1段ポアソン過程)

3.一軸圧縮,一軸引張および圧裂引張試験結果

 3.1 強度とクリープ寿命

 3.2 気乾と湿潤状態での強度

4.周圧下での圧縮試験結果

5.考察

 5.1 周圧の影響

 5.2 寸法効果

6.まとめ

References

キーワード:岩石,強度,破壊寿命,ワイブル分布,構成方程式,確率過程論


A Consideration on Probability Distribution of Strength and Creep Life of Rocks

Abstract

Probability distribution of strength under uniaxial stress was examined on the basis of published data. It was found that strength followed the Weibull distribution. Shape parameter or coefficient of variation in air-dried condition gave good agreement with that in water-saturated condition.

Probability distribution of failure time in creep testing was also examined on the basis of published data. Failure time also followed the Weibull distribution. Shape parameter of creep life was found to agree well with that of strength.

Probability distribution of strength under triaxial stress field is considered to be important, however, only a few studies have been published. In this study, a tuff and a mudstone were tested under triaxial stress. It was found that strength followed the Weibull distribution. Shape parameters of tuff by this study and andesite by Yamaguchi did not change so much with confining pressure, however, that of mudstone increased notably.

The experimental data were discussed from not only deterministic but also stochastic points of view.

KEY WORDS: Rock, Strength, Creep Life, Weibull Distribution, Constitutive Equation, Stochastic Process