NUMERICAL SIMULATION ON DYNAMIC DEFORMATION CHARACTERISTICS OF LIGHT WEIGHT SOIL WITH DIFFERENT EPS PARTICLE SIZES BY DISCRETE ELEMENT METHOD

In order to explore the influence laws of EPS (Expanded Polystyrene) particle sizes on the dynamic deformation characteristics of light weight soil, under the conditions of 15% cement content and 50% EPS particles volume ratio, indoor dynamic triaxial tests of light weight soil with EPS particle sizes of 1 ~ 3 mm, 3 ~ 5 mm, and 5 ~ 6 mm are carried out. Light weight soil numerical models are established by using the PFC3D discrete element software, and the micro mechanical properties of light weight soil with different EPS particle sizes are discussed from two aspects of contact force and displacement field. The results show that as EPS particle sizes increases, the weak contact surface between EPS particles and solidified soil particles increases, and stress concentration is easy to occur. The dynamic strength of light weight soil decreased by 5.75% ~ 20.04% and 7.06% ~ 34.96% with the increasing of EPS particle sizes from 1 ~ 3 mm to 3 ~ 5 mm and 5 ~ 6 mm, respectively. The contact force between EPS particles and soil particles is smaller than that between soil particles in the numerical models. With the increasing of the loads, the contact force of particles increases, and the particles move from the two ends to the middle. With the increasing of EPS particle sizes, the distributions of contact force are more uneven, the specimens are easier to be destroyed, and the displacement field is asymmetrical. However, the displacement interface gradually moves to the middle position with the increasing of loads. It is consistent with the laws that the macroscopic dynamic strength of light weight soil decreases with the increasing of EPS particle sizes. © 2021, Journal of GeoEngineering. All Rights Reserved.