The Investigation On Stability Of The Bank Slope Of The Dam Near Ci Ha Xia Hydropower Station

As the current analytical theories and methods of the bank slope stability are inadequate, this thesis is an analysis of the engineering geological environment and deformation characteristics of the bank slopes of Ci Ha Xia Hydropower Station, it is also a study of the evolution of deformation and a discussion of the formation mechanism of the deformation. The study is based on the engineering geological environment of the bank slopes near Ci Ha Xia Hydropower Station, the engineering geology and earth system science theory. Taking 3# landslide and 4# toppling near Ci Ha Xia Hydropower Station as research objects, it adopts methods such as comprehensive theoretical analysis, qualitative evaluation and numerical calculation on the basis of data from actual measurement of level holes, drilling and laboratory test, ect. The research is reflected in the following several aspects.(1) After an in-depth analytical research on the developmental characteristics, formation conditions and mechanical issues of failure deformation of the rock mass near the dam, it reveals the failure deformation characteristics related to rock mass toppling and sliding are dumping deformation, bending deformation, shape damage, slip bending and buckling deformation.(2) Toppling and cracking phenomenon of rock mass near the dam is extremely complex. After making a systematical geological record and research analysis, the complex rock slope deformation phenomena can be summarized as continuous toppling, toppling bent and toppling fracture-the three basic forms.(3) This paper is based on the investigation of the toppling and cracking phenomenon of rock mass and the research of fracture types, and makes a further analysis of the interactive relationship among various types of fracture. It divides formation and evolution of toppling rock mass into four basic developmental stages-the early toppling deformation stage, bending-splitting deformation stage, the bending slate root forms continuous cracking surface, sliding-cracking deformation stage.(4) According to the complex phenomenon of deformation and fracture, mechanical mechanism and the relationship between the extent of rock toppling and it, the intensity of deformation has two-levels. On this basis, a qualitative analysis is made through some basic indicators such as the changes of rock inclination, the unloading deformation and weathering characteristics of rock toppling.On the basis of the above study, the paper makes an in-depth analysis of 3# landslide and 4# toppling rock mass's failure deformation patterns when the reservoir water storage is 2980m, calculates and evaluates the stability under various working conditions by applying the limit equilibrium methods.