Efficient optimization parameter calibration method-based DEM simulation for compacted loess slope under dry-wet...

Area of Science:

• Geotechnical Engineering
• Computational Mechanics

Background:

• Compacted loess slopes are susceptible to deterioration from dry-wet cycles, impacting fill slope safety.
• The discrete element method (DEM) is suitable for analyzing discontinuous and anisotropic geotechnical materials like loess.

Purpose of the Study:

• To analyze the stability of compacted loess slopes under dry-wet cycles using DEM.
• To develop an efficient parameter optimization method for DEM models in geotechnical analysis.
• To introduce a new indicator, the bonding ratio (BR), to assess loess degradation.

Main Methods:

• Implemented a chaotic particle swarm optimization with sigmoid-based acceleration coefficients algorithm (CPSOS) for DEM parameter calibration.
• Introduced and utilized the bonding ratio (BR) to characterize pore and crack development during dry-wet cycles.
• Established a DEM-based slope stability analysis model for compacted loess under cyclic wetting and drying.

Main Results:

• The CPSOS method accurately calibrated DEM parameters, reflecting actual stress-strain and strength trends under dry-wet cycles.
• The bonding ratio (BR) effectively quantified the degradation of loess bonding due to dry-wet cycles.
• DEM analysis confirmed that dry-wet cycles negatively impact loess slope safety factors, with a trend towards stabilization over cycles.

Conclusions:

• The proposed DEM approach with CPSOS calibration and BR indicator provides a reliable method for analyzing compacted loess slope stability under dry-wet cycles.
• DEM accurately simulates the degradation effects of dry-wet cycles on loess slopes, validating its use in geotechnical engineering.
• The findings contribute to understanding and mitigating risks associated with loess slopes in environments with fluctuating moisture content.