doi:10.16186/j.cnki.1673-9787.2022090063

Received:2022/09/24

Revised:2023/01/10

Published:2024/01/25

Micro-investigation of shear properties of mixed sand on discrete element method

HONG Yong, JIANG Yichen, NI Jianan, YU Chao

School of Civil Engineering，Qingdao University of Technology，Qingdao 266520，Shandong，China

Abstract: Objective In order to study the difference of shear strength and volume deformation of sand with different components during shear failure. Methods The method of laboratory test and discrete element simulation is used to establish the PFC2D model of shear zone，and the variation law of meso-parameters of single sand and mixed sand during shear failure was studied. Results It is found that there are significant differences in shear zone morphology，volumetric strain rate and other mesoscopic parameters among coarse sand，fine sand，standard sand and mixed sand. Conclusion The results show that the shear stress of sand is affected by particle composition.The shear stress of sand increases with the increase of coarse particle content，and the shear stress of mixed sand is higher than that of single sand with the same composition.The movement of sand particles is mainly in the upper and lower spans.The larger particle size is，the greater the movement displacement is，and the higher the bulk strain rate is.The bulk strain rate of sand in shear is affected by particle composition.The bulk strain rate of coarse sand is higher than standard sand and fine sand.The bulk strain rate of mixed sand is higher than that of single sand with the same composition.The research results can provide theoretical reference for the failure of geological structure of sandy soil.

Key words:sandy soil;particle gradation;shear strength;volumetric strain rate;discrete element;porosity