Abstract
Large-scale accumulation bodies composed of loose materials are among the theoretical and practical topics of greatest interest to engineers and scientists. Although accumulation bodies have been widely studied across multiple academic disciplines, the impact of particle materials on mechanical properties remains insufficiently explored. The motivation for this study is to investigate the relationship between the fabric characteristics of large-scale accumulation bodies and their shear mechanical properties, field investigations were conducted to obtain particle size distribution characteristics, which led to determining the fractal dimension D as a descriptor of the fabric. For samples with different fractal dimensions, we conducted large direct shear tests and MatDEM numerical simulations. The topological characteristics of the particle contact network during shear were then analysed using a complex network method. The results revealed that the accumulation bodies' shear strength obtained from both the physical and numerical experiments first increased but then decreased with increasing fractal dimension, following a normal distribution with a mean value of 2.5 and an amplification factor that is proportional to the vertical load. The analysis of complex network parameters also has consistent patterns. On the basis of these experimental results, this study investigates the shear mechanical properties of accumulation bodies from both macroscopic and microscopic perspectives, providing deeper insights into the link between macroscopic responses and the mesoscale structure of force chains, explaining the mechanism by which fractal dimensions affect their shear characteristics and providing new evaluation methods for the utilization and stability assessment of large-scale accumulation materials.