Study on Failure Characteristics of Basalt Subjected to Triaxial Cyclic Loading

As a special kind of engineering material, the mechanical properties and failure characteristics of rock directly determine the safety of the engineering works. In this paper, to estimate the indicator of rock failure under seismic loading, the axial plastic strain development of basalt under different lithology and different frequency is studied based on triaxial cyclic loading test. A magnitude of 10-3 is obtained for the critical plastic strain of basalt at failure. The mean value of critical plastic strain is 0.003. A seismic analysis of underground powerhouse complex of the Baihetan HPP is then conducted as a study case. The development of rock mass's plastic strain with seismic loading is studied, and failure zones which have the worst effects on the complex are revealed.