Cyclic Shearing Response of Granular Material in the Semi-Fluidized Regime

Author(s): 
Andres R. Barrero, William Oquendo, Mahdi Taiebat, Arcesio Lizcano
Date: 
Wednesday, June 13, 2018
First presented: 
Geotechnical Earthquake Engineering and Soil Dynamics
Type: 
Published paper
Category: 
Geotechnical

Liquefaction is a phenomenon usually observed in saturated granular soils when subjected to monotonic or cyclic shearing under constrained volumetric conditions. Liquefaction is usually associated with a loss of mean effective stress due to generation of excess pore pressure during the shearing of soil. In this process the particles reduce, or in the extreme case may lose, contact with each other. This nearly contact-free state is known as “semi-fluidized regime”. In this state, the soil behaves almost like a viscous fluid, but the properties and origins of this response are not well understood. This study presents a series of numerical simulations using Discrete Element Method (DEM) to model the constant volume cyclic shearing of three granular assemblies with different packing fractions. The variations of the stress-strain response and the corresponding coordination number for each sample are tracked when the semi-fluidized regime is achieved. The results show the semi-fluidized regime in all of these assemblies regardless their packing fraction. This micro-mechanics based approach to the analysis can elaborate on the variations of the coordination number, mean effective stress, and developed shear strains before and after entering such regime.

Feature Author

Dr. Arcesio Lizcano

Arcesio is a civil engineer with more than 30 years of experience in geotechnical engineering including research and teaching in soil mechanics. He has extensive experience in engineering design and construction, including construction oversight of foundations, excavations, road embankments, retaining structures, and stockpiles and waste dumps.

Arcesio specializes in understanding the behaviour of sand and clays and applying that understanding to practical problems. He has contributed to civil and mining projects in Asia, Europe, Africa, North and South America. He has published over seventy papers in journals and conferences.

Soil Mechanics Specialist
PhD, Geotechnical Engineering
SRK Vancouver
SRK Worldwide