Multivariate adaptive regression splines analysis for 3D slope stability in anisotropic and heterogenous clay

Abstract

Little research can be found in relation to the stability of anisotropic and heterogenous soils in three dimensions. In this paper, we propose a study on the three-dimensional (3D) undrained slopes in anisotropic and heterogenous clay using advanced upper and lower bounds finite element limit analysis (FELA). The obtained stability solutions are normalized, and presented by a stability number that is a function of three geometrical ratios and two material ratios, i.e. depth ratio, length ratio, slope angle, shear strength gradient ratio and anisotropic strength ratio. Numerical results are compared with experimental data in the literature, and charts are presented to cover a wide range of design parameters. Using the multivariate adaptive regression splines (MARS) analysis, the respective influence and sensitivity of each design parameter on the stability number and the failure mechanism are investigated. An empirical equation is also developed to effectively estimate the stability number.