Triggers and deformation mechanism study of reservoir landslide through multi-fields information interpretation

Due to the construction of Three Gorges Dam, many old landslides have been revived with the impoundment of reservoir water, which pose great threaten to the lives of residents. Deformation observed in a reservoir landslide is the result of a complex multi-field and dynamic evolution process. In order to gain a comprehensive understanding of the deformation mechanism and evolution process of a reservoir landslide, multi-fields information need to be monitored. Taking Majiagou landslide located at Three Gorges Reservoir Region (TGRR) as an example, a Distributed fiber optic sensing (DFOS) based monitoring system was developed and implemented. The multi-fields information including seepage (rainfall, water level, pore water pressure), deformation and strain-stress variation were monitored in real time. Through analyzing the recorded data with grey correlation analysis method, the factors that trigger the deformation of Majiagou landslide were identified. By further linking the mechanical parameters of soil with seepage field, the deformation mechanism was revealed as well. This paper has provided an advanced multi-fields information monitoring and data interpretation method, which can be widely adopted in reservoir landslide study.