Improvement of microstructure of granular soil in the densification process caused by impact loading

Abstract

Improvement of the mechanical properties of soil, such as density, compressibility and shear strength, is typically due to the variation in its inherent microstructure. This paper presents a microscopic study of the densification mechanism in granular soils subjected to impact loading. Both model test and discrete element simulation were carried out to quantitatively analyze the fabric evolution from a particle-scale perspective. Irregularly shaped particles were used in the simulation, on basis of which realistic packing structural information such as average contact number, contact area and branch vector length could be learned. The results reveal the microscopic densification mechanism that impact loading not only promotes the increase of contact number, but also enhances the contact area around per particle. Increasing of contact area has enriched the distribution of sutured contacts to form more steady mechanical status of soil.