Shear strength indices predication model for coarse-grained soil based on particle gradation and moisture content information
摘要
Shear strength indices are crucial for evaluating the stability of geotechnical bodies, especially for accurately assessing the stability of slopes in waste disposal sites. However, effective prediction models for the shear strength of coarse-grained soils are still lacking. This study investigates the influence of moisture content (MC), maximum particle diameter (MPD), and gradation parameters (GP) on the shear strength of waste materials through large-scale direct shear tests. Results reveal that increasing MC (2–12%) leads to a significant decrease in internal friction angle (up to 26.91%) and a non-linear change in cohesion. Larger MPD (20-60 mm) correlates with increased internal friction angle (up to 62.98%) but shows no significant effect on cohesion. The gradation parameter b negatively affects both internal friction angle and cohesion, while parameter m exhibits a complex relationship with these properties. Based on these findings, we propose an empirical predictive model for shear strength indices in coarse-grained soils. Validation against data from various waste disposal sites yields correlation coefficients (R2) of 0.835 for cohesion and 0.804 for internal friction angle, demonstrating the model's applicability to coarse-grained soils with rock content ≥ 32%. This study enhances our understanding of shear strength in heterogeneous waste materials and provides a valuable tool for geotechnical stability assessments.