Multidimensional Analysis of Precursor Information of Rockburst during Loading and Unloading of Deep Diorite

At present, rockburst disasters cannot be predicted accurately, and the prevention control of deep underground engineering are significantly challenging. To explore evolution law precursory information instability, test diorite was conducted with high confining pressure different unloading rates (0.1 MPa/s, 0.3 0.5 0.7 0.9 MPa/s). Multidimensional analysis is carried out by evaluating deformation features, fast Fourier transform (FFT), energy entropy, singular spectrum power entropy. The results show that Poisson’s ratio hook-shaped before rockburst, elastic modulus in shape a step, ringing count surge after quiet period, three-dimensional 0.98 σ c ~ stress location space shows large red ball distribution along shear plane, id="M2"> b value fluctuates low-value range, low-frequency amplitude high-frequency low fluctuate range 300 s, frequent abnormal fluctuations entropy curve. above research can considered precursor information, which enriches theoretical method explosion disaster prediction.