Study On Prediction Of Mountain Reservoir Bank Collapse In Southeast China

Reservoir bank collapse is one of the typical engineering geological problems after impoundment, who seriously affects the security, economic and ecological environment in the reservoir area. Compared to plain reservoir, mountain reservoir bank with the characteristics of high and steep slope, complex topography, Coarse granular soil layer, high water level and so on, has a more complex and less studied bank collapse problem. On the basis of the full use of existing data collection, several typical mountain reservoirs are investigated and studied. Overall, the southeastern mountain reservoirs with low mountains, hills landform, cover layer of coarse particles of soil, bank collapse phenomenon is mainly developed in the slope covered with thick layer of bank protection erosion mode, type of collapse the lord.For in-depth systematic study of bank collapse mechanism, the relationship of each factor with bank collapse and so on, based on the study of bank collapse phenomena and geological conditions, we do a lot of physical simulation experiments with mechanism simulation. In multivariate experiment who is designed with orthogonal design and analyzed with range analysis, four important factors in collapse of bank are selected to study the sensitivity of the width of bank collapse to the factors.The result shows that the sensitivity of bank collapse in width in descending order of the various factors: slope gradient, slope material composition, wave size, water level. The several physical simulation experiments with different slope topography, different water level, different slope sedimentation, different slope flat form, different density, bank collapse time effect, and scaling of reservoir bank collapse mechanism are done to visually analysis bank collapse rules and mechanisms.Based on field investigation and observation of physical simulations, the reservoir bank collapse mechanism is divided at a constant water level and water level changes. At a constant water level, reservoir bank is destroyed gradually by the comprehensive actions of oftening, hydration, wave action erosion and so on. Because the influences of rock and soil composition, slope construction, slope morphology and so on, the reservoir bank collapse gradually changes to erosion and collapse-type or sliding type. With water level changes, the reservoir bank is destroyed gradually by the superposition of repeatedly consant water level reservoir bank collapse in the range of variation in water level. A comprehensive analysis of reservoir bank collapse in the composition and slope gradient, slope material, the size of the waves, water level in the relationship and mechanisms is did.Based on a lot of reservoir bank collapse physical simulation, a reservoir collapse width prediction formula is established with multiple regression method. Then the applicable conditions and method parameter values of the prediction method are given. According to existing data, the formula is preliminarily verified.