DEFORMATION CHARACTERISTICS AND MECHANISM ANALYSIS OF GEOLOGICAL HAZARDS DURING OPERATION PERIOD OF THREE GORGES RESERVOIR

This paper further summarizes the deformation characteristics and mechanism of geological hazards in Three Gorges Reservoir Area. It bases on the professional monitoring data of 189 geological hazards. It deeply studies the displacement-time curve of geological hazards. The results show the following findings. (1)From 2017 to 2019,the deformation situation of the geological hazards generally tended to be gentle. The deformation mainly occurred from May to September,and rainfall became the main inducing factor. According to the annual deformation and the macroscopic deformation of geological hazards,it can be divided into four categories: non-deformation or micro-deformation,slow deformation,relatively obvious deformation,obvious deformation. (2)According to the cumulative displacement-time curve characteristics of GNSS,the deformation characteristics of geological hazards can be divided into three basic types: Oscillatory type,linear type and step-like type. The displacement of step-like landslides is the main deformation form of geological hazards with obvious deformation and relatively obvious deformation,which is the focus of geological hazards. (3)Through the analysis of deformation characteristics and trigger factors,eight kinds of step-like type deformation characteristics of geological hazards during the operation period of the Three Gorges Reservoir are summarized. The deformation modes under the action of different trigger factors are put forward. The differences of the cumulative displacement-time curve in four aspects,such as the morphological characteristics of the deformation of step-like,the height,the occurrence time and the repetition regularity are concluded. The paper can provide a basis for deformation analysis and early warning of geological disasters in the Three Gorges Reservoir area.