岩石の二軸試験
圧縮-圧縮, 圧縮-引張組合わせ応力下における平板試験片の力学的挙動
1981 年 97 巻 1116 号 p. 77-82
詳細
1981 年 97 巻 1116 号 p. 77-82
In order to study the failure criterion of rocks under the combined stresses, the biaxial tests were undertaken on three kinds of rocks, namely OGINO tuff, KAWARAGO tuff and KIMACHI sandstone. For these tests, a biaxial testing machine using the rock plate specimen was designed as shown in Fig. 3 and Fig. 4.
The main results obtained in this study are summarized as follows;
1) The failure strength of rocks under the combined stresses of compression-compression changes with the intermediate principal stress as shown in Fig. 6. The maximum value of failure strength of KAWARAGO tuff in compressioncompression test is about 1.4 times the uniaxial compressive strength, KIMACHI sandstone about 1.9 times and OGINO tuff about 1.3 times. The increase of failure strength of rocks incompression-compression test shows that the magnitude of the intermediate principal stress has a considerable influence on the magnitude of the fracture strength.
2) The failure limiting line of rocks in compression-tension test gives the curved line part and the straight line part. The curved line part shows the range which the failure strength of rocks decreases as the tensile stress increases, and the straight line part shows the range which the failure strength approaches gradually to the uniaxial tensile strength.
