Deformation laws of cyclic disturbance and a failure precursor feature of marble under high stresses

In order to explore its deformation and failure laws under cyclic disturbance, a series of uniaxial tests of marble with different stress levels and cyclic amplitudes are carried out. The research results show that: (1) The stress level is the decisive factor whether the marble specimens tend to failure or not, and the cyclic amplitude is a relatively minor factor. When the stress level just reaches the dilation one, the rock specimen can not fail even if it is under a much larger cyclic amplitude. When the stress level is much higher than the dilation stress and the cyclic amplitude is given a much larger value, the rock will rapidly fail. (2) Compared with the irreversible deformation, the dynamic stiffness can better reflect the transition features of sparse-dense-sparse stages. The positive and negative values of decay rate of the dynamic stiffness can be used as the features of failure precursor, and the rock failure can be predicted at the stable deformation stage. (3) For the failed marble specimens, the damage variable based on the dynamic stiffness characterization is similar to the general trend of irreversible deformation. The double-high mode is consistent with the type Ⅰ curve, and the rest of the curves are consistent with the type Ⅱ curve.