Applied Research Of Saturated-unsaturated Embankment Dam Slope Reliability Analysis By Kriging Method

Slope stability analysis of embankment dam often serves as an important basis for the safety evaluation, however, slope stability analysis under unsaturated seepage flow is always a hot and difficult issues in water conservancy engineering research. Because the traditional single safety factor method can't quantitatively analyze the impact of different uncertainties on the slope stability. In order to evaluate dam slope safety issues effective and objective, this paper is based on the theory of probability reliability analysis methods, introducing Kriging method, then using the failure probability and reliability index to assess the safety of embankment dam. The main contents are as follows:(1)Based on the Van Genuchten model theory, Bishop method and the shear strength theory, the formula of safety factor and the corresponding reliability analysis actual performance function can be established, then the slope reliability of saturated-unsaturated embankment dam were analyzed under the action of steady seepage by Monte Carlo simulation(MCS). The research results can reveal the change regulation of the stability and reliability of the dam slope under seepage conditions.(2)Development of dams slope reliability analysis method by Kriging method, combined with the basic random variables which impact of slope stability and corresponding statistical characteristics, based on Latin Hypercube Sampling method, Kriging method, GEOSTUDIO software and the corresponding batch program, and then, establish Kriging model(actual performance function) by select the appropriate the regression model and relevant function type. Finally, the slope reliability of saturated-unsaturated embankment dam were analyzed systematic under the action of steady seepage. Compared with the MCS, the proposed method has high computational efficiency, just dozens operation can be obtained more accurate results. It can be an effective tool to the analysis of embankment dam stability and reliability under steady seepage.(3)The dams slope reliability analysis method was established by considering spatial variability of the dam material parameters. Based on the random field theory, slope reliability problems was transformed to a plurality of random variables problems after the relevant non-Gaussian random field was discretized by Karhunen-Loève(K-L) expansion method. And then, slope reliability of saturated-unsaturated embankment dam which considered spatial variability of the dam material parameters was analyzed by Kriging model. The result shows that the proposed method can effectively consider the dam spatial variability of material parameter on the dam slope stability.