石炭強度の載荷速度依存性に関する研究

1.はじめに

2.実験試料

 2.1 試料採取地点と試料ブロック

 2.2 実験計画と試験片の作成

3.一軸圧縮試験

4.一軸引張試験

5.圧裂引張試験

6.考察

 6.1 強度試験と完全応力−歪曲線

 6.2 時間依存性と載荷速度依存性

7.まとめ

参考文献

キーワード:石炭,一軸圧縮強度,一軸引張強度,圧裂引張強度,完全応力−歪曲線,載荷速度依存性,時間依存性挙動


Loading-Rate Dependency of Coal Strength

Abstract

Uniaxial compression, uniaxial tension and indirect tension (Brazilian) tests were carried out for coal (anthracite) obtained in a coal mine located about 26 km west of Beijing.

Complete stress-strain curves not only in uniaxial compression test but also in uniaxial tension test were successfully obtained. In post-failure region of uniaxial tension test, the curve showed Class Tcharacteristics accompanied with small amount of residual strength. The peak strength obtained by the uniaxial tension test was far less than the indirect tensile test frequently conducted.

The strain rate was alternatively increased and decreased to obtain the loading-rate dependency. When strain rate was increased, stress increased abruptly by a certain amount depending on the loading-rate dependency of the rock. The experimental results showed that loading-rate dependency of the coal both under the uniaxial compression and tension stress was relatively smaller than the most rocks that had been tested by the authors.

Key Words: Coal, Uniaxial Compression Strength, Uniaxial Tension Strength, Indirect Tension Strength, Complete Stress-Strain Curve, Loading-Rate Dependency, Time-dependent Behaviour