Influence of Finite Deformations in the Stress-Strain Modelling of Granular Media
An incremental formulations of the stress-strain law is presented for quasi-static deformation of granular solids. The stress-strain relationship is derived for an element of granular...
Instability and Plastic Flow of Soils
Materials should according to Drucker's postulate become unstable when the second increment of plastic work is negative. Experimental observations however show otherwise....
Constitutive Relations for Large Deformation Plasticity
Influence of the choice of measures of stress and deformation upon the representation of constitutive relations for elasto-plastic solids undergoing finite deformation is discussed. The...
A Micromechanics Model for Rough Interfaces
A new constitutive model for transfer of interfacial tractions along rough cracks in strain softening composites is presented. The model relates the normal and shearing stresses on the...
Penetration Tests in a Particulate Calibration Chamber
A numerical technique which couples discrete element method with boundary element method has been developed to simulate a two dimensional particulate assembly. Soil particles in the near...
Comparison of a Microscopic Model and a Macroscopic Model Predictions on the Stress-Strain Behavior of a Soil
The stress-strain behavior of a soil under drained triaxial conditions was simulated using the Microscopic constitutive model TRUBAL. The model parameters for the Macroscopic constitutive...
Microscopic Modeling of Shear Strength of Contaminated Soils
The degradation of shear strength of soils due to prolonged contamination of soils is an emerging problem. The experiments conducted at New Jersey institute of Technology showed a gradual...
Constitutive Relations for Granular Solids Accounting for Heterogeneous Deformation Fields
Under high deviatoric stress levels corresponding to large strains, the deformation of granular media is highly heterogeneous. A micro-mechanical approach is developed here to model the...
A Time-Dependent Microplane Model for Creep of Cohesive Soils
The microplane model is used in this paper to describe the time-dependent (creep) behavior of cohesive soils (clays). The constitutive equations are defined on each of a set of microplanes...
Factors Affecting the Incremental Stiffness of Particle Assemblies
A simple numerical experiment was performed on an assembly of densely packed spheres in order to investigate the factors that affect an assembly's incremental stiffness. The...
Numerical Undrained Cyclic Loading Simulations Using the Discrete Element Method
Three dimensional numerical experiments on random arrays of rough spheres were performed using the discrete element method to study the behavior of granular soil and the results were compared...
Numerical Experiments for Anisotropic Behavior of Granular Materials
A three dimensional discrete element computer code 'TRUBAL' is used to investigate the effect of initial anisotropy on stress-strain and volume change characteristics...
Microstructure and Stress Differences in Shearing Flows
Steady shearing flows of highly inelastic particles are simulated using rigid and slightly deformable sphere models. Large first normal stress differences in small systems are observed,...
Interparticle Sliding and Rolling
Numerical experiments are done with a continuum plasticity program in order to study the initiation and evolution of shear bands. Many elements are used in order to resolve families of...
Measurement of Subsurface, Deep Foundation and Slab/Subgrade Conditions with In Situ Seismic, Sonic and Vibration Methods
Case histories are presented to illustrate quality assurance and forensic applications of nondestructive testing and evaluation (NDT&E) methods for in situ investigation of subsurface...
Wave Equation Modelling of the SPT
The stress wave propagation in the Standard Penetration Test (SPT) is described in this paper. It is shown that the SPT is a complex dynamic system and that both force and motion measurements...
An Expert System for Estimating Soil Strength Parameters
An expert system to aid in selecting shear-strength parameters for use in stability analysis was developed for use on a PC. It provides guidance in interpreting strength measurements and...
Monte Carlo Simulations of the Dynamic Response of Pile Groups
A study is presented on the effect of variations of relevant parameters within a pile group on the vertical dynamic response of the group. These parameters include the shear wave velocity...
Modification of
The response of piles in a rectangular group subjected to lateral loading has been analyzed using a three-dimensional finite element model to evaluate the effect of pile spacing on lateral...
An Inexpensive Automatic Control System for Soil Testing
This paper describes an inexpensive automatic control system for soils testing. The system comprises a microcomputer, an analog to digital converter, a relay board, and solenoid valves....
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