New Relationships Between Particle Meso-Mechanical Parameters and CBR of Graded Crushed Stone Pavement: Influence Factors Analysis

The disposal of tunnel waste slag has emerged as a major ecological challenge. Highway pavement bases require large quantities of graded crushed stone as fill material, but large-scale quarrying of such stone also poses significant environmental problems. An innovative approach involves crushing tunnel waste slag into graded crushed stone for use as fill material, offering an economical and environmentally friendly solution to both issues. However, the performance of this recycled graded crushed stone needs to be carefully evaluated. This study employed particle flow analysis software to simulate the California Bearing Ratio (CBR) test process, followed by analysis and verification to assess its performance. A CBR model was developed and validated, the meso-mechanical parameters of the penetration process were analyzed, and the results were examined in terms of both CBR values and particle contact force fields. The findings indicated that different particle stiffness ratios kn/ks had no significant effect on the CBR test, while the friction coefficient μ showed a linear positive correlation with the CBR value. It was also concluded that the slenderness ratio of the contact force field first increased and then decreased with an increase in the stiffness ratio kn/ks. As the friction coefficient μ increased, the slenderness ratio of the contact force field decreased accordingly. This study provides valuable insights into the influence of meso-mechanical parameters on the performance indicators of graded crushed stone pavement and offers a promising approach for the processing and reuse of tunnel waste slag to alleviate ecological pressures.