ABSTRACT
Beishan is the site selected for disposal of high-level radioactive wastes in China. The repository tunnels will be excavated with TBM method. The mechanical behavior of the host rock was tested under low-frequency cyclic loading on the Rockman 207 triaxial apparatus. The test results show that the axial and lateral strains at fatigue failure are limited by the static post-peak stress-strain curves of the rock. The accumulative residual strain under cyclic loading represents the fatigue damage in the rock. The fatigue process is composed of three stages in the light of the change in the residual strain rate. The strain rate decreases with the cycle number in stage I; it is a constant rate in stage II and an accelerated strain rate in stage III. The maximal stress during cyclic loading changes the residual strain proportions from the three stages and affects the fatigue life of the rock.
