Experimental Study on the Strength Failure Characteristics of Columnar Jointed Rock Masses under Three-Dimensional Stress

摘要: In view of the typical anisotropy columnar jointed basalt in dam area Baihetan Hydropower Station on Jinsha River China, rock mass models with different column angles (α = 0°–90°) were constructed similar materials, and three sets intermittent joints are considered physical models. Uniaxial equal-confining-pressure triaxial compression tests carried out a true testing machine, variations failure mechanisms, stress-strain relationships, strength characteristics masses joint inclination angle investigated under stress conditions. The results revealed following: 1) during compression, two types curves existed, namely ideal plastic curve strain-hardening curve; 2) elastic modulus sample uniaxial presented U-shaped variation α. Moreover, samples increased change α Er significantly increase confining pressure. 3) There four within compression. addition, test data used to verify that Mogi criterion good applicability three-dimensional stress. An empirical prediction model relationship between pressure was established, its applicable conditions analyzed. is verified by mass, which indicates agreement data. Finally, modes loading summarized.