Behaviour of piles subjected to passive subsoil movement due to embankment construction - a simplified 3D analysis

Two trial piles were installed at the berm section of an embankment in the later stage of its construction and one of them was fitted with an oversized casing to isolate its top 3. m from the action of surrounding soil. Lateral bending behaviour these two piles subjected to passive sub soil movements were very different from each other because of the casing and is modelled in this paper using a three dimensional analysis. The effect of relative stiffness of the piles on their lateral bending behaviour is investigated. The effect of interface joint slip on the pile's behaviour is also investigated in a later section of this paper

Settlement analysis of foundation soil over long time and comparison with field performance

This paper models the consolidation of the foundation soil of a wide geogrid reinforced embankment close to its centre-line. An elastic viscoplastic model has been used for the analysis. A creep function that takes into account of the non-linear nature of creep has also been incorporated in this model. The predicted results are compared with the field measurement data and with the analysis results obtained using two other models (i.e. Kutter and Sathialingham, 1992 and modified Cam-Clay)

An Investigation of Instability on Constant Shear Drained (CSD) Path under the CSSM Framework: A DEM Study

Soil liquefaction or instability, one of the most catastrophic phenomena, has attracted significant research attention in recent years. The main cause of soil liquefaction or instability is the reduction in the effective stress in the soil due to the build-up of pore water pressure. Such a phenomenon has often been thought to be related to the undrained shearing of saturated or nearly saturated sandy soils. Notwithstanding, many researchers also reported soil instability under a drained condition due to the reduction in lateral stress. This condition is often referred to as the constant shear drained (CSD) condition, and it is not uncommon in nature, especially in a soil slope. Even though several catastrophic dam failures have been attributed to CSD failure, the failure mechanisms in CSD conditions are not well understood, e.g., how the volumetric strain or effective stress changes at the triggering of flow deformation. Researchers often consider the soil fabric to be one of the contributors to soil behaviour and use this parameter to explain the failure mechanism of soil. However, the soil fabric is difficult to measure in conventional laboratory tests. Due to that reason, a numerical approach capable of capturing the soil fabric, the discrete element method (DEM), is used to investigate the CSD shearing mechanism. A series of simulations on 3D assemblies of ellipsoid particles was conducted. The DEM specimens exhibited instability behaviour when the effective stress paths nearly reached the critical state line. It can be clearly observed that the axial and volumetric strains changed suddenly when the stress states were close to the critical state line. Alongside these micromechanical observations, the study also presents deeper insights into soil behaviour by relating the macro-observations to the micromechanical aspect of the soil