Linking shear strength to granular skeleton state of continuously graded coarse-grained soils: Insights from discrete element modelling. (June 2022)

• Record Type: Journal Article
• Authors: Xie, Yipeng; Yang, Junsheng; Zhang, Cong; Qu, Tongming; Fu, Jinyang; Wang, Shuying
• Is Part Of: Computers and geotechnics. Volume 146(2022)
• Publication Date: 2022-06
• Subjects: Coarse-grained soils -- Peak friction angle -- Granular skeleton state -- Discrete element method -- Particle size distribution; Engineering geology -- Data processing -- Periodicals; Soil mechanics -- Data processing -- Periodicals; Rock mechanics -- Data processing -- Periodicals; 624.1510285
• DOI: 10.1016/j.compgeo.2022.104750
• Languages: English
• ISSNs: 0266-352X

Abstract

Abstract: Particle size distribution (PSD) affects the strength behavior of continuously graded coarse-grained soils by modifying the granular skeleton state. However, due to the lack of a proper indicator linking the skeleton state to PSD, the quantitative relation between shear strength and granular skeleton state remains unexplored. Based on a concept of effective dominant skeleton size d ed in multi-sized particle packing model, this study attempted to link granular skeleton state with friction angles of continuously graded coarse-grained soils. Using the discrete element method (DEM) and an improved PSD model, dense packing specimens with 36 PSDs were generated and conducted for biaxial tests. The results indicate that d ed has a strong correlation with the size and stress distribution of active particles, i.e., d ed can reflect the overall size level of skeleton particles in continuously graded granular soils. A definite semi-log linear correlation between φ p and d ed was revealed, wherein fitted intercept A and slope B were found to be related to particle-scale strength properties. According to the similarity of φ p - di relation in uniform-sized particles and φ p - d ed relation in continuously graded soils, a method for estimating φ p of coarse-grained soils with any PSD was proposed and validated by a series of experimental direct shear tests.