Study On Permeability Test And The Stability Of The Dam With Clay Core Dam

Earth-rock dam is most widely used in water conservancy buildings in the world. And center wall dam of it is widely used. In a practical application, stability and safety of earth-rock dam are the most notable aspects. According to the statistics, filtration problem is an important factor which affect the safety of dam. Therefore, filtration problem of earth-rock dam should be given enough attention. In the practical monitoring of earth-rock dam, due to the sudden changes in the reservoir water level, the unsteady seepage will come into being in earth-rock dam body and the water level in the dam is higher than reservoir water level. While in unstable flow conditions, there are obvious differences in the infiltration under variation of the dam seepage line with the stability, rate of descent saturation line lags behind the rate of change in the water level, and the water level in the dam may even be higher than dam case the water level, adversely affect the safety of the dam, easily induced instability and failure. Therefore, the study of variation in the unstable flow conditions at the dam saturation line and changes in dam stability under conditions of rapid draw-down library can provide valuable theoretical basis for the actual construction and operation of embankment dam’s safety. It will produce great significant economic, social and environmental benefits.This paper adopts the combined method of theoretical analysis, laboratory tests, model tests and numerical simulation. It’s aimed to study the influencing mechanism between seepage problems caused by the change of water level to the dam seepage line and the dam stability. And providing science embankment dam safety monitoring reasonable reference.At first through the literature data, this paper summarizes the current domestic and foreign research status of earth and rock-fill dam and the saturation line calculation theory, and determined the dam saturation line change within the three main factors:Dam seepage path length, the water level drop rate and permeability coefficient. Through the model test, design different condition and research on control of dam body seepage line change under the condition of the three influencing factors of the change of inside the dam saturation line. And find that the longer the dam seepage path length, the faster the water level drop, the smaller the permeability coefficient, the more obvious hysteresis, the longer the time lag.Through numerical analysis study of earth dam dam slope stability under different working conditions, and apply the strength subtraction research in water effect on the stability of the dam body. Finally summarizing the research achievements of model test and numerical analysis, put forward under the condition of unsteady seepage of dam body seepage line experience and theoretical calculation formula and test fitting equation, the comparative analysis, the formula of two kinds of phreatic line can be relatively stable seepage saturation line formula under the condition of better description of changes in water level drop under the condition of saturation line. It’s suitable for safety assessment of dam under unstable seepage condition.