Load-Unload Response Characteristics and Prediction of Reservoir Landslides

Lunan Wang, Echuan Yan, Yanchao Wang, Shaoping Huang, Yong Liu
Many cases indicate that groundwater played an important role in reservoir landslides triggering around the Three Gorge Reservoir. To explore the load-unload response characteristics and predict the occurrence of reservoir landslides induced by groundwater, a prediction model is established. In this model, (1) different mechanical effects of groundwater to a landslide are simplified into a total water pressure head in the landslide body. (2) The model is based on the load-unload response theory
more » ... oad response theory in which total water pressure head is treated as the load-unload parameter and deep displacement acceleration of landslides as the load-unload response parameter, (3) The load and unload stages of total water pressure head are distinguished by the response increment of deep displacement acceleration. Taking the Lijiapo landslide for example, the results show that (1) the response relationship between deep displacement of the landslide and total water pressure head has an obvious hysteretic nature. (2) In the hydrological year of 2011, the total water pressure head has a loading process of 178 days and an unloading process of 187 days affecting the landslide. (3) In the most time, the load-unload response ratio is approximately equal to 1, indicating that the landslide is in a stable stage. However, the load-unload response ratio in July and August increases suddenly, indicating that the landslide deviates from the stable stage for a short period of time and large deformation may appear. The result of prediction model is well coincident with the deformation phenomenon of landslide. All the above-mentioned results show that the prediction model can be used to perform the prediction of reservoir landslide induced by groundwater.