Reliability-Based Design Optimization of Pile Stabilized Earth Slopes Aided by Pareto Optimality

Stabilizing piles are known as promising structures for earth slope reinforcement and landslide mitigation, and stability analysis for slopes reinforced with piles under 3D conditions has been widely carried out. However, the optimization design of stabilizing piles for achieving a balance between safety and cost efficiency is still challenging and rarely reported. In this paper, under 3D slope conditions and geological uncertainties, a framework for the multi-objective optimization design of stabilizing piles based on the first-order reliability method (FORM) is presented. The study firstly conducts limit analysis to build a deterministic pile stabilized slope stability model. By accounting for the soil shear strength uncertainties, reliability analyses of the 3D reinforced slopes are carried out based on the prescribed stabilization patterns. In the end, a probabilistic multi-objective design procedure using the Pareto optimality theory combining the reliability analysis results are presented. An illustrative example of a 3D earth slope reinforced with piles is given to explain the feasibility of reliability-based design method which helps to attain the trade-off between the two conflict objectives, i.e., the cost and safety, for practical engineering.

Keywords: Pile stabilized slope, 3D limit analysis, reliability-based design, multi-objective optimization.