Study On Features And Prediction Parameters Of Bank Failure Of Sevral Typical Mountain Reservoirs

Bank failure that affected and controlled by many factors is a very complex geological history.Bank failure would threaten lives and property of people on both sides,distruct farmland,block traffic and shorten the life of reservoirs.In present,the study on the mechanism,type and prediction parameters of bank failure of mountain reservior is not systematic and not deep enough.This paper based on the field surveys and laboratory analysises on eight typical mountain-revoir which are Three Gorges,Ertan,Baozhusi,Dachaoshan,Tianshengqiao Yiji,Zipingpu,Manwan and Xiaowan,the features and the prediction parameters of bank failure has been in-depth systemadically studied,and achieved the following main results:1. Based on field investgation on bank failure status of eight typical mountain reseviors, the geological environmental conditions (topography, lithology, geological structure, human activity), slope shape, bank structure type and library hydrodynamic conditions have been summarized systematically,the distribution that bank failure changed with the bank shape and structure has been statistical analysised.It is revealed that bank failure of mountain reseviors mainly developed in the convex slope and plot of residual slope.2. The formation conditions and the charateristics of each bank failure mode have been summarized.Four new modes of bank failure have been abtained ,which are slump-type,collapse-slide conversion,slide-collapse conversion and ancient(old) landslide-collapse.3. There are seven bank-failure models in mountain reservoirs,such as erosion,collapse,slide,slump-type, collapse-slide conversion,slide-collapse conversion and ancient(old) landslide-collapse.Statistics show that collapse and slide are the main bank-failure mode ,which accounted for 51.85% and 30.69%,and erosion accounted for 5.56%.4. The measured parameters of mountain bank failure has been statistical analysised. Pridiction parameters of bank failure is affected by internal and external factors .Internal factors includes lithology,slope shape,mineral composition ,bank and geological structure;external factors includes wave function,physical and chemical effects of reservoir water,the role of water level,rainfall,vegetation,human activities,and so on.5. Based on statistical analysis and the factors,the recommended pridiction parameters of bank failure of typical mountain reservoirs have been given.