Stability Monitoring and Numerical Simulation of Weathering Transition Zones in Dam Slopes of Tropical Islands

Rainfall infiltration and groundwater fluctuations induced by cyclonic rainfall are the main causes of slope failure. Slope stability monitoring is key to preventing and controlling rock slope failure. Aiming at the monitoring theory and technical problems of dam slope failure under a cyclonic rainfall environment, this study carried out a physical model test and numerical simulation on the stability monitoring of the weathering transition zone in rock slopes. The results show that: (1) Under cyclonic rainfall, the increased permeability, the expansion of the rock fracture network, and the decrease of effective stress are the main causes of increased lateral deformation of the slope. (2) Physical model test results showed that rain spatter erosion and runoff erosion could lead to rapid loss of anchor bolt preload. In the hydraulic fluctuation stage, the anchor bolt axial force decreased first, then increased, and finally tended to be stable. The unloading response of the Intelligent Terminal Structure was significant during rock block sliding. In the numerical simulation, the anchor bolt axial force increased continuously with the increase of lateral displacement of slope. (3) By analyzing the evolution of anchor bolt axial force and pore water pressure in the weathering transition zone, a monitoring criterion for the stability of the weathering transition zone of rock slopes based on the Logistic function was proposed.