Evaluating Long-Term Stability of Embankments on Soft Soils: A Numerical Study with Taguchi Optimization
摘要
Predicting the long-term stability of embankments on soft coastal soils remains a critical geotechnical challenge due to the high variability and creep behaviour of these soils. This study addresses the issue using a combined approach of numerical simulations and optimization, employing the Taguchi method within the design of experiments framework. Embankments with pile-stabilized slopes were analysed using PLAXIS 3D with the soft soil creep model, based on an L54 orthogonal array generated in Minitab. Settlement at the embankment centre and lateral pile-head displacement were evaluated. Sensitivity analysis identified the modified creep index (μ*) as the most influential parameter, impacting settlement and displacement by 9.9% and 9.3%, respectively. Taguchi optimization ranked key parameters for creep settlement (μ* > c′ > κ* > ϕ′ > d > λ* > OCR > s > ν) and lateral displacement (μ* > ϕ > c′ > λ* > κ* > d > ν > s > OCR). ANOVA highlighted significant interactions, particularly between Poisson’s ratio and pile spacing with p values of 0.024 and 0.026 for settlement and lateral displacement, respectively. Surface response curves illustrated parameter interdependencies. The study demonstrates the effectiveness of the Taguchi method in optimizing embankment design, offering a robust and economical solution for long-term stability on soft soils.