Probabilistic Slope Stability Analysis Of Rockfill Dams Based On Limited Shear Strength Data For Rockfills

Hydraulic structure reliability analysis is a method for evaluating the safety of hydraulic structures.In the slope stability analysis of the rockfill dam,the shear strength parameters are considered as random variables,and a small amount of data obtained from indoor tests is fitted to obtain the probability distribution of the shear strength parameters.And then a series of reliability methods are used to analyzes the stability of the dam.In the analysis of the stability of the usual rockfill darms,the shear strength parameters of the materials are often regarded as independent random variables.However,recent researches have found that there are certain correlations between shear strength parameters.The correlation will have a great impact on the stability of dam.In addition,indoor triaxial tests show that although the dam materials are treated manually and are more uniform than natural materials,but the shear strength parameters of the materials still have variability.This variability has led to various uncertainties in the stability analysis of dam,including the inherent uncertainty of the parameters,model uncertainty due to calculation method assumptions,and statistical uncertainty due to limited experimental data.How to incorporate the statistical uncertainty caused by limited data into the stability analysis of dam is still a question worth exploring.In view of the above problems,the stability reliability analysis of rockfill dams under the limited data of shear strength parameters is studied in this paper,and its effectiveness is verified.The main contents are as follows:1.This paper discusses some limitations in the field of reliability analysis of rockfill dam,and proposes the opinion that using two-dimensional normal distribution or use Nataf transformation to convert relevant non-normal variables into normal variables to deal "with shear strength parameters is not reasonable enough;2.The method of constructing any two-dimensional joint probability distribution of shear strength parameters based on the Copula function is introduced,and the difficultiesin characterizing the different correlation structures between the shear strength parameters are solved,and probabilistic slope stability analysis of rockfill dams based on the Copula function is proposed;3.The statistical uncertainty caused by the limited test data of shear strength parameters is discussed.The variability of various statistics in the reliability analysis is measured by the Bootstrap method,and failure probability interval estimation method of rockfill dams based on Bootstrap method is proposed;4.The effectiveness and applicability of "probabilistic slope stability analysis of rockfill dams based on the Copula function" and "failure probability interval estimation method of rockfill dams based on Bootstrap method" are verified by a case study of Nuozadu rockfill dam;5.A software "Earth-rock Dam Reliability Analysis Software based on Copula method"(WHUERDR)is compiled based on Matlab programming language using the method proposed.The software can analyze the correlation between shear strength parameters and analyze the reliability of any form of earth-rock dam or slope.