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Full-Text Articles in Engineering
Coupled Hydro-Geochemical Modelling Of A Permeable Reactive Barrier For Treating Acidic Groundwater, Buddhima Indraratna, Punyama Pathirage, Kerry Rowe, Laura Banasiak
Coupled Hydro-Geochemical Modelling Of A Permeable Reactive Barrier For Treating Acidic Groundwater, Buddhima Indraratna, Punyama Pathirage, Kerry Rowe, Laura Banasiak
Buddhima Indraratna
This study focuses on coupling geochemistry with geo-hydraulics to enable time-dependent modelling of the remediation of acidic groundwater using an alkaline permeable reactive barrier (PRB). Chemical clogging due to secondary mineral precipitates reduces the porosity and hydraulic conductivity of the reactive medium. The governing equations are incorporated into commercial numerical codes, MODFLOW and RT3D. An original algorithm was developed for RT3D to simulate geochemical reactions occurring in the PRB. The results and the model predictions are in agreement, confirming that the hydraulic conductivity reduction due to mineral precipitation occurs at the start of permeation and continues until halfway through the …
Radial Consolidation Modelling Incorporating Downdrag Effect For A Multi-Layer Soil, Cholachat Rujikiatkamjorn, Buddhima Indraratna
Radial Consolidation Modelling Incorporating Downdrag Effect For A Multi-Layer Soil, Cholachat Rujikiatkamjorn, Buddhima Indraratna
Buddhima Indraratna
A system of vertical drains (PVDs) with preloading is a successful method for promoting horizontal drainage and accelerating soil consolidation. A piecewise technique is used to capture the radial consolidation in the multi-layer soil system to incorporate (a) the effect of soil downdrag and (b) smear zone where soil permeability varying linearly. The effect of soil dragged down from the upper soil layer into the lower layer has been analysed in terms of required time for consolidation. It can be seen that the consolidation of the multi layer soil depends on the interaction between 2 adjacent layer, penetration depth, and …
3d Numerical Modelling Of Hexagonal Wire Mesh Reinforced Embankment On Soft Bangkok Clay, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Dennes T. Bergado
3d Numerical Modelling Of Hexagonal Wire Mesh Reinforced Embankment On Soft Bangkok Clay, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Dennes T. Bergado
Buddhima Indraratna
The numerical modeling of the full scale test embankment reinforced with hexagonal wire mesh was analyzed using finite difference method under three dimensional (3D) conditions to reflect the actual embankment dimensions. In the analysis, the 3D finite difference simulation using 5 times of vertical laboratory permeability can reasonably predict its behavior on soft foundation. In comparison with the field measurements, the predicted results from 3D analysis reasonably agreed with measured data including vertical settlement, excess pore pressures and lateral displacements. Thus, the actual embankment geometry and the selected permeability influenced the behavior of the reinforced embankment constructed on soft ground …
Track Stabilisation With Geosynthetics And Geodrains, And Performance Verification Through Field Monitoring And Numerical Modelling, Buddhima Indraratna, S Nimbalkar, Cholachat Rujikiatkamjorn
Track Stabilisation With Geosynthetics And Geodrains, And Performance Verification Through Field Monitoring And Numerical Modelling, Buddhima Indraratna, S Nimbalkar, Cholachat Rujikiatkamjorn
Buddhima Indraratna
All over the world, ballasted railway tracks form one of the major transportation networks designed to provide heavy haul freight and passenger traffic. However, large cyclic loading from heavy axle trains operating at high speeds often causes excessive deformation and degradation of ballast, as well as unacceptable differential settlement of compressible foundation and, or pumping of the soft subgrade soils. The problem becomes more severe under high impact loads due to rail or wheel imperfections, causing accelerated ballast breakage. A proper understanding of load transfer mechanisms and their effects on track deformations are essential prerequisites for minimising maintenance costs. The …
Modelling Of Soft Ground Consolidation Via Combined Surcharge And Vacuum Preloading, Buddhima Indraratna, Cholachat Rujikiatkamjorn, Ali Ghandeharioon
Modelling Of Soft Ground Consolidation Via Combined Surcharge And Vacuum Preloading, Buddhima Indraratna, Cholachat Rujikiatkamjorn, Ali Ghandeharioon
Buddhima Indraratna
A system of vertical drains combined with vacuum and surcharge preloading is an effective approach for promoting radial flow to accelerate soil consolidation. When a higher load is required to meet the desired rate of settlement and the cost of surcharge is also significant, the application of vacuum pressure with reduced surcharge loading can be used. The equivalent 2-D plane strain solution for multi-drain analysis is described with the inclusion of the effects of vacuum pressure and smear zone caused by mandrel driven vertical drains. A large-scale radial consolidometer is employed to determine the extent of the smear zone and …
Modelling Of Combined Vacuum And Surcharge Preloading With Vertical Drains, Buddhima Indraratna, Cholackat Rujikiatkamjorn, Richard Kelly
Modelling Of Combined Vacuum And Surcharge Preloading With Vertical Drains, Buddhima Indraratna, Cholackat Rujikiatkamjorn, Richard Kelly
Buddhima Indraratna
In this study, 2D and 3D numerical analyses were conducted to predict embankment behaviour on soft clay foundations stabilised by Combined Vacuum and Surcharge Preloading. To determine the equivalent plane strain permeability, a revised conversion procedure for plane strain condition considering linear permeability variation in the smear zone is proposed. The equivalent permeability coefficients are then incorporated in finite element codes, employing the modified Cam-clay theory. The advantages and limitations of vacuum application through vertical drains are discussed through two selected case histories from China and Australia and the predictions are compared with the available field data. Apart from realistic …