Analysis of wave propagation in dry granular soils using DEM simulations

Abstract

In this paper, a three-dimensional particlebased technique utilizing the discrete element method (DEM) is proposed to study wave propagation in a dry granular soil column. Computational simulations were conducted to investigate the soil response to sinusoidal motions with different amplitudes and frequencies. Three types of soil deposits with different void ratios were employed in these simulations. Different boundary conditions at the base such as rigid bedrock, elastic bedrock, and infinite medium were also considered. Analysis is done in time domain while taking into account the effects of soil nonlinear behavior. The computational approach is able to capture a number of essential characteristics of wave propagation including motion amplification and resonance. Dynamic soil properties were then extracted from conducted simulations and used to predict the response of the soil using the widely used equivalent linear method program SHAKE and compare its predictions to DEM results. Generally, there was a good agreement between SHAKE and DEM results except when the exciting frequency was close to the resonance frequency of the deposit where significant discrepancy in computed shear strains between SHAKE predictions and DEM results was observed.

Fluctuation and self-diffusion research about dry granular materials under shearing

“…The DEM-based simulation has advantages of faster computation speed, simpler program, having parallel computing function and no convergence problem existing. Besides, the DEM simulations offer a lot of messages both at the macroscopic and microscopic levels that can be retrieved at any time during simulations and enables a comprehensive assessment of the response [19]. Compared to experiments, the DEMbased simulations provide an easier solution to predicting the flow and mechanical characteristics, since the flow velocities and displacements as well as the contact information of granules can be easily accounted from the simulation data [20].…”

A Study of the Parameters of Coefficient of Friction, Porosity, Particle Diameter, Density and Dispersity on Wave Propagation Velocity

“…The results are compared with the results of the equivalent linear method performed using SHAKE software. SHAKE and DEM are generally consistent except when the loading frequency is close to the resonant frequency 13 .…”

Elastic wave propagation in dry granular media: Effects of probing characteristics and stress history

“…The wave velocities can be readily estimated as the ratios of the source-receiver distances to the travel times. Time domain techniques are widely applied for both bender element experiments (Gu et al, 2015;Camacho-Tauta et al, 2015;Da Fonseca et al, 2009) and numerical simulations (Mouraille et al, 2006a;Zamani and El Shamy, 2011;O'Donovan et al, 2016;Otsubo et al, 2017). In experiments, only a few number of transducers or bender/extender elements are attached to the surface of the specimen, which makes the interpretation of wave signals a difficult task.…”