不均質な岩石試験片中に発生する応力分布とそのひずみ測定に関する研究
方解石から構成される大理石の場合
1979 年 95 巻 1098 号 p. 455-460
詳細
1979 年 95 巻 1098 号 p. 455-460
In many cases, rocks are composed of many crystal grains, and the stress distribution under uniform external force is not homogeneous but rather heterogeneous. This heterogenity is caused by the difference of elastic constants of each crystal grain. On the other hand, to measure the elastic constants of crystalline aggregate as a whole, it is necessary to eliminate the influence of individual grain properties. Therefore, the length of the strain gage must be considered carefullyf or the measurement. In this study, elastic constants of marble are measured, varying the gage length, and then, FEM analyses of uniaxial compression of marble composed of calcite are carried out. The results are follows;
1. Tensile stress greater than or equal to the 0.5 times as large as the axial compression stress is induced in the cross sectional plane of the specimen.
2. This tensile stress may elongate pre-existing cracks or nucleate new cracks.
3. To measure the elastic constants of crystalline rock specimen, the volume of specimen must be greater than 500 times grain volume.
4. The length of strain gage must be longer than 10 times apparent grain size.
