Optimal Estimation of Shear Strength Parameters Based on Copula Theory Coupling Information Diffusion Technique

Abstract

In geotechnical reliability analysis, random volatility in marginal distributions of shear strength parameters has been rarely considered. Unfortunately, conventional marginal distribution models cannot characterize real probability distribution accurately, leading to considerable dispersion with incomplete probabilistic information. In this paper, an estimation methodology is proposed based on copula theory coupling information diffusion technique. Firstly, information diffusion distribution is extended to represent one-dimensional marginal distributions of shear strength parameters. Secondly, copula theory is employed to characterize the dependence structures among the parameters. Eventually, equivalent sample is yielded by information diffusion distribution that has been already established. A case study in Singapore is implemented to enunciate and validate the competence of the proposed method. The performances of the candidate copulas coupling different marginal distributions are further discussed. Results indicate that information diffusion distribution can efficiently capture the random volatility of real distributions of shear strength parameters and hold remarkable superiority in modeling marginal distributions. The equivalent sample, estimated by information diffusion technique in conjunction with Gaussian copula, has considerable consistency with original data. The proposed method can provide a reference to reliability analysis in geotechnical engineering.

Copula-Based Method for Estimating the Minimum Void Ratio Parameters of Tailings Deposits

“…Zhang et al [9,10] introduced the advantages of using the copula function for fitting the non-normal distribution characteristics of shear strength parameters and established a Bayesian method for modelling the bivariate distribution using finite data. Zhou et al [11] proposed an estimation method based on the copula coupling information diffusion technology, which could effectively capture the random volatility of the real distribution of parameters. Huang et al [12] proposed the method of estimating the shear strength parameters based on the copula function [13].…”