Model test study on centroid frequency evolution of reservoir landslide under water level fluctuations

This study investigates the evolution of centroid frequency in reservoir landslides under cyclic fluctuations of reservoir water levels, using both theoretical analysis and physical model tests. Theoretical investigations examined the attenuation characteristics of longitudinal waves, shear waves, and Rayleigh waves in viscoelastic media. Physical model tests simulated landslide evolution under different water-level fluctuation rates, and the centroid frequency variations throughout the landslide process were analyzed. The results show that water-level fluctuations do not directly alter centroid frequency values. However, the associated decline in landslide stability leads to pronounced frequency depression in centroid frequency. The evolution of centroid frequency is significantly affected by the fluctuation rate: the faster the fluctuation, the lower the landslide stability and the more noticeable the frequency variation. Sensitivity to landslide changes also varied across monitoring locations, with more significant changes observed near the landslide toe and on the surface compared to deeper sections. Notably, the downward trend in centroid frequency occurred prior to landslide failure, with changes exceeding 7 Hz, indicating its potential as an early-warning indicator. Nevertheless, the reliability and general applicability of centroid frequency as a warning metric require further validation. This study provides new insights and methods for understanding the dynamic evolution of reservoir landslides and improving landslide monitoring and early-warning systems.