Modeling of Geomaterials Behavior

Abstract

The review of 50 years of papers published in Soils and Foundations demonstrates that signiˆcant eŠort has been made by many researchers to develop soil models. The contributions of Soils and Foundations in the area of soil modeling are subdivided into two topics: (a)``macro''-mechanics and (b)``micro''-mechanics. The attention to macro-mechanics is focused on continuum-based models, whereas that to micro-mechanics is focused on discrete based models. Soils are examples of complex systems, made up of basic units that interact to generate an emergent response that is more complex than the response of the units themselves. Despite the challenges posed by the complexity of the systems, our understanding of the link between the particles, their interactions and the overall``macro-scale'' soil response has signiˆcantly been improved over the life of Soils and Foundations. In this review of contributions to soil modeling, many examples of macro-scale soil models developed with a real consideration of the mechanical response of the individual particles were found.

Development of a Generalized Methodology for Soil-Structure Interaction Analysis Using Nonlinear Time-Domain TechniquesNEAMS Program, DOE Office of Nuclear Energy (NE-41)

“… In recent years, nonlinear models have been developed which can adequately model the hysteretic behavior of soils in the time domain. In advanced versions, such features as pressure dependence and cyclic degradation are also included [15].…”

“…Soil-Structure Interaction, Time Domain Techniques Page 58 Some recent examples where (mostly for 1-D soil analysis) explicit inclusion of changes in soil response based upon intensity has been accounted for include Phillips [40] and Drosos [14]. When the actual 3-D soil properties are considered, many authors note the significant dependence on confining pressure, pore pressure, and void ratio, all of which can change drastically in the presence of reactor rocking motions, see for example Zefra [10], Bonilla [9], Reyes [41], Gellis [42], and the review article by Soga [15], who notes the "experimental finding that volume change upon shearing is associated with the mean pressure change along with shear induced dilatancy". Assimaki [8] notes "Laboratory experimental data on sand samples subjected to high confining pressures, show that for highly confined materials, both the standard shear modulus reduction factor and the damping versus shear strain amplitude overestimate the capacity of the soil to dissipate energy".…”

“…In the absence of scattered waves from the structure, this results in the following solution 15 Note that for an intermediate layer one element thick, the set of nodes which are members of the intermediate layer but not a member of the inner boundary is equivalent to the set of nodes on the boundary with the outer region, that is…”

Nonlinear time-domain soil–structure interaction analysis of embedded reactor structures subjected to earthquake loads

“…In recent years, nonlinear models have been developed which can adequately model the hysteretic behavior of soils in the time domain. In advanced versions, such features as pressure dependence and cyclic degradation have been included, as discussed in the work of Soga and O'Sullian (2010).…”

Micromechanical Behavior of DNA‐1A Lunar Regolith Simulant in Comparison to Ottawa Sand

“…The analysis at the grain scale has helped researchers to improve their understanding on the complex behavior of granular materials and analyze multiscale problems (Guo & Zhao, 2016;O'Sullivan, 2011;Soga & O'Sullivan, 2010). The parameters obtained through micromechanical tests at the grain scale (for example, interparticle friction, normal and tangential stiffness) comprise important input in numerical simulations using DEM analyses, for example, in the analysis of the macroscale response of granular materials subjected to monotonic or cyclic loading and the flowability behavior of granular materials (Huang et al, 2014;Iverson et al, 2011;Sazzad & Suzuki, 2011;Yan et al, 2015).…”