Effects of water contents on stick-slip mechanism at the granite-basalt interface

This paper studies the stick-slip behaviors in heterogeneous fault groups composed of granite and basalt with various water contents. This study analyzes the impact of shear loading rate, normal stress and water content on the stick-slip events through laboratory experiments. The findings reveal that shear stress drops decrease with increasing shear loading rates, they increase as water content and normal stress increase, and the friction on the heterogeneous fault group increases with increasing velocity. Moreover, the study identifies three failure modes of mineral particles on the contact surface, leading to two types of stick-slip events in the heterogeneous fault group. Additionally, based on the experimental data, the relationship among shear stress drop, normal stress and friction coefficients is established to predict shear stress drops in earthquakes by only utilizing the normal stress and friction coefficients of the fault system. Furthermore, a displacement-based prediction model is proposed to estimate earthquake occurrence time based on current displacement of the fault, slip rate of the fault and the total displacement of a seismic activity. The study contributes to a deeper understanding of stick-slip behavior influenced by various water contents, and presents potential avenues for monitoring and forecasting seismic activities. The experimental results provide valuable insights into the mechanism of fault behaviors in heterogeneous conditions, contributing to the field of earthquake study and seismic hazard assessment.