The Analysis On The Uncertainties Of The Safety Factor Of Spillway Base Plate Stability Against Sliding On Rockfill Dam Body

Along with build dams technology's maturity and its own characteristic, the earth-rock dam has more competitive advantage than other types of dam. When the earth-rock dam was built in the narrow gorges, the spillway was disposed on the dam directly, because situation of precipitous lies in the mountain of two sides. The safety of this arrangement needs to further confirm.In the former project, many target of evaluation about dam safety are safety factor, for some uncertainties parameter, people often select a comprehensive value to carry on the computation, so there are some deficiencies in theory. In order to more objective and accurate appraisal latent risk and safety coefficient's risk, this article uses reliability theory and take the actual project as an example, focus on the impact of the random variable uncertainty of the rockfill dam spillway imbricate-bottom. Monte-Carlo method of the reliability theory is used to calculate the stability against sliding risk when the fluctuation pressure, seepage pressure acting, drag force and rockfill internal friction angle is uncertain. Through the analysis, the randomness of each influencing factor has certain influence to the safety coefficient is discovered. The analysis discovered that in many uncertainty factor, the influence of the spillway base plate stability against sliding safety was made by the dam internal friction angle is biggest. With the increase of discharge , the fluctuation pressure obviously increases, and simultaneously the pressure of the bottom has increased.