Abstract. The characteristic frequency was generated when blasting seismic wave propagate in rock mass. The characteristic frequency played an important role in the amplitude attenuation of seismic wave with time and propagation distance. Rock mass was simplified as visco-elastic media. The time attenuation model of seismic wave amplitude was studied by wave equation and the complex number theory. Theoretical analysis demonstrates that attenuation coefficient of seismic wave amplitude with time is mainly affected by rock viscosity coefficient and elastic modulus. The attenuation coefficient decreases with increase of elastic modulus. The attenuation coefficient increases with increase of viscosity coefficient. The test method of equivalent elastic modulus of rock mass was analyzed according to model of time attenuation of seismic wave amplitude in situ. The wave velocity test verified effectiveness of the method. A new method of determining rock mass mechanical parameter was put forward.

Seismic wavelet plays an important role in the processing and interpretation of seismic data. And wavelet is also the premise of forward modeling and inversion of seismic wave. So it is important to study the formation process and formation rule of seismic wavelet. The viscoelastic properties of geologic body can be represented using Kelvin medium. The formation rule of seismic wavelet was analyzed using the mathematical model of propagation process of rectangle pulse in Kelvin medium. The experimental results have shown that characteristic frequency and band width were major frequency spectrum parameters causing the variation of waveform. The characteristic frequency and band width decreased with the increase of propagation distance. The characteristic frequency decreased in negative exponential law and became stable finally. The change of characteristic frequency and band width was related to the mechanical parameters of medium. With the increase of propagation distance, characteristic frequency decreased more slowly as elastic modulus increased than as viscous coefficient increased. The correlation coefficient increased with the increase of propagation distance, i.e., waveform became stable at last. Ratio of stability distance to characteristic wave length increased with the increase of elastic modulus and the decrease of viscous coefficient, then tended to become stable.

Rock materials are often subjected to cyclic loads during construction. A full understanding of the deformation behavior of rock under cyclic loads is of great significance in engineering. In this study, by using the endochronic constitutive model proposed by Valanis, the reinforcement function form and constitutive parameters of the endochronic model are improved. An endochronic plasticity constitutive program for rock based on the finite element method is used to study the mechanical properties of rock under different cyclic loading conditions (of maximum loading stress, amplitude, and confining pressure), and through the use of red sandstone, marble, and basalt, experimental and simulation results are compared to verify the model. The results show that the theory can better simulate the hysteresis loop width and cumulative plastic strain of rock under cyclic loading and, under different loading conditions, the numerical simulation results are consistent with the actual rock experimental law. Therefore, the endochronic plasticity constitutive model in this study can be applied to investigate the influence of cyclic loading on the dynamic deformation behavior of rock.