A Hydro-Chemo-Mechanical Analysis of the Slip Surface of Landslides in the Three Gorges Area of China
Landslides in the Three Gorges area of China are often triggered by rainfalls of significant acidity which potentially lead to wetting effects by rainfall precipitation and mineralogical changes induced by adverse chemical reactions. This paper presents a hydro-chemo-mechanical analysis of slope stability in this context. It first surveys typical landslide events that occurred in the Three Gorges area where mineralogical changes were identified and further simulated in the laboratory; both field and laboratory evidences strongly suggest that these changes contributed to the weathering and strength decline of sliding masses. Subsequently numerical simulations are conducted to investigate possible scenarios of strength evolution due to rainfall induced wetting as well as mineralogical changes. The factor of safety of potential slip surfaces is computed under different combinations of hydrological and chemical scenarios. The results of a parametric study indicate the potential consequences of hydro-mechanical and chemo-mechanical processes that may play an important role in the landslides in the Three Gorges area.