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Preparation of uniform and identical soil samples in the laboratory is quite challenging and some times not possible. In addition, experimental studies are quite tedious, expensive and often difficult to achieve desired stress or strain in the laboratory and more importantly study of behaviour of granular materials at micro scale is not possible. Inorder to overcome these difficulties and limitations, numerical techniques such as DEM can be implemented. DEM proposed by Cundall et al. (1979) has gained lot of demand in monitoring the behaviour of granular materials. Through this, interaction of particles can be captured contact by contact and motion of the particles are modelled particle by particle.
Therefore, various researchers have adopted DEM in analysing the cyclic liquefaction behaviour where one can have good control on sample preparation. (various recent authors contribution from DEM and experimental strudies)It was found out that liquefaction resistance was governed by the magnitude of pwp generation, which is highly influenced by the magnitude of ini-tial static shear stress. However, there has not been enough research done in investigating the cyclic liquefaction behaviour under the influence of initial static shear stress at micro level. As replicated soil samples with similar fabric at micro level can be prepared very easily in DEM and hence effect of initial static shear stress, confining pressure and initial void ratio on the generation of excess porewater pressure can be explored at micro and macro level. DEM has gained lot of demand for the study of behaviour of soil at particle scale. But the ability of DEM in capturing the behaviour of granular soils under cyclic loading under aniso-tropic consolidation path has not yet been fully explored. This can be achieved by simulating cyclic triaxial test using DEM. Therefore in my current study, 3D modelling of cyclic triaxial test is performed for an assemblage of spherical particles under undrained conditions. Parametric study was conducted to evaluate the influence of confining pressure, amplitude of cyclic shear stress and density on liquefaction resistance at micro level. Eventually their contribution in defining the lique-faction susceptibility is analysed by using CSSM.
Therefore, various researchers have adopted DEM in analysing the cyclic liquefaction behaviour where one can have good control on sample preparation. (various recent authors contribution from DEM and experimental strudies)It was found out that liquefaction resistance was governed by the magnitude of pwp generation, which is highly influenced by the magnitude of ini-tial static shear stress. However, there has not been enough research done in investigating the cyclic liquefaction behaviour under the influence of initial static shear stress at micro level. As replicated soil samples with similar fabric at micro level can be prepared very easily in DEM and hence effect of initial static shear stress, confining pressure and initial void ratio on the generation of excess porewater pressure can be explored at micro and macro level. DEM has gained lot of demand for the study of behaviour of soil at particle scale. But the ability of DEM in capturing the behaviour of granular soils under cyclic loading under aniso-tropic consolidation path has not yet been fully explored. This can be achieved by simulating cyclic triaxial test using DEM. Therefore in my current study, 3D modelling of cyclic triaxial test is performed for an assemblage of spherical particles under undrained conditions. Parametric study was conducted to evaluate the influence of confining pressure, amplitude of cyclic shear stress and density on liquefaction resistance at micro level. Eventually their contribution in defining the lique-faction susceptibility is analysed by using CSSM.