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Selected Works

Buddhima Indraratna

Selected Works

2014

Vacuum

Articles 1 - 8 of 8

Full-Text Articles in Engineering

Performance And Prediction Of Marine Clay Treated With Vacuum And Surcharge Consolidation At Port Of Brisbane, Buddhima Indraratna, A S. Balasubramaniam, Harry Poulos, Cholachat Rujikiatkamjorn, Jayantha Ameratunga Mar 2014

Performance And Prediction Of Marine Clay Treated With Vacuum And Surcharge Consolidation At Port Of Brisbane, Buddhima Indraratna, A S. Balasubramaniam, Harry Poulos, Cholachat Rujikiatkamjorn, Jayantha Ameratunga

Buddhima Indraratna

During the past decade, the application of vacuum preloading for stabilising soft coastal clay and other low-lying estuarine soils has become popular in Australia. The cost-effectiveness isa major factor in most projects in view of the significantly reduced time for achieving high degree of consolidation. Due to an increase in trade activities at the Port of Brisbane, new facilities on Fisherman Islands at the mouth of the Brisbane River will be constructed on the new outer area (235 ha) adjacent to the existing port facilities via land reclamation. A vacuum assited surcharge load and conventional surcharge scheme in conjunction with …


Performance And Prediction Of Vacuum Combined Surcharge Consolidation At Port Of Brisbane, Buddhima Indraratna, Jayantha Ameratunga, Cholachat Rujikiatkamjorn, Harry G. Poulos, A S. Balasublamaniam Mar 2014

Performance And Prediction Of Vacuum Combined Surcharge Consolidation At Port Of Brisbane, Buddhima Indraratna, Jayantha Ameratunga, Cholachat Rujikiatkamjorn, Harry G. Poulos, A S. Balasublamaniam

Buddhima Indraratna

During the past decade, the application of vacuum pressure for stabilising soft coastal clay and other low-lying estuarine soils has become increasingly popular in Australia, mainly due to the proven costeffectiveness in view of the significantly reduced time for achieving a high degree of consolidation and enhanced shear strength. Due to an increase in trade activities at the Port of Brisbane, new facilities on Fisherman Islands at the mouth of the Brisbane River will be constructed on the new outer area (235ha) adjacent to the existing port facilities via land reclamation. A scheme of vacuum assisted surcharge load in conjunction …


Vertical Drains, Vacuum Consolidation & Preloading, Buddhima Indraratna Mar 2014

Vertical Drains, Vacuum Consolidation & Preloading, Buddhima Indraratna

Buddhima Indraratna

Due to the rapid increase in population, and the subsequent industrial and construction boom, especially in the urban and coastal regions, many countries have intensified the inevitable need for developing infrastructure on problematic soils, including soft compressible clays and deposits with low bearing capacities. Moreover, good quality geological materials for construction are also becoming scarce, a problem exacerbated by the numerous environmental constraints imposed in various countries. Because of these reasons, and environmental restrictions on certain public works, ground improvement has now become an integrated and essential component of infrastructure development. Consequently, civil engineers are forced to utilise even the …


Current State Of The Art In Vacuum Preloading For Stabilising Soft Soil, Cholachat Rujikiatkamjorn, Buddhima Indraratna Mar 2014

Current State Of The Art In Vacuum Preloading For Stabilising Soft Soil, Cholachat Rujikiatkamjorn, Buddhima Indraratna

Buddhima Indraratna

In this paper the analytical solutions for radial consolidation that include time dependent surcharge loading and vacuum pressure are proposed, whilst also considering the impact of the parabolic variation of permeability in the smear zone. The use of the spectral method for multilayered soil consolidation is introduced and verified. The Elliptical Cavity Expansion Theory is used to predict the extent of soil disturbance (smear zone) caused by the installation of mandrel driven vertical drains. The predicted smear zone is then compared to the data obtained from large-scale radial consolidation tests. Furthermore, the advantages and limitations of applying a vacuum through …


Ground Improvement At The Port Of Brisbane, Australia Using Vertical Drains And Vacuum Assisted Preloading, Buddhima Indraratna, Cholachat Rujikiatkamjorn, A S. Balasubramaniam Mar 2014

Ground Improvement At The Port Of Brisbane, Australia Using Vertical Drains And Vacuum Assisted Preloading, Buddhima Indraratna, Cholachat Rujikiatkamjorn, A S. Balasubramaniam

Buddhima Indraratna

Soft clays in coastal areas have low shear strength and high compressibility. Thus construction activities for infrastructure developments in these deposits often pose geotechnical problems due to large time dependent settlements and lateral movements. Ground improvement techniques are adopted to reduce the water content of the soft clays by preloading techniques with vertical drains. Depending on the magnitude of the surcharge used substantial immediate settlement with lateral movements can takes place during preloading. This in tum causes stability problems in the loaded areas. The use of vacuum assisted preloading has now become a popular method in Australia where substantial loads …


Numerical Prediction Of Unsaturated Ground Behavior Influenced By Vegetation And Vacuum Consolidation, Cholachat Rujikiatkamjorn, Buddhima Indraratna, B Fatahi Mar 2014

Numerical Prediction Of Unsaturated Ground Behavior Influenced By Vegetation And Vacuum Consolidation, Cholachat Rujikiatkamjorn, Buddhima Indraratna, B Fatahi

Buddhima Indraratna

Bioengineering including native vegetation is an ancient method of improving the stability of slopes. In modern railway engineering, this technique is re-captured for increasing the soil stiffness and shear strength of subgrade beneath rail tracks. Currently this practice has become increasingly popular in Australia for stabilising railway corridors built over expansive clays and compressive soft soils. This paper looks at the stabilisation role by suction generated by both the natural vegetation and the artificial vacuum application using the numerical analysis. For demonstrating the role of native vegetation, a mathematical model for the rate of root water uptake was incorporated in …


Radial Consolidation Model Incorporating The Effects Of Vacuum Preloading And Non-Darcian Flow, Kourosh Kianfar, Buddhima Indraratna, Cholachat Rujikiatkamjorn Mar 2014

Radial Consolidation Model Incorporating The Effects Of Vacuum Preloading And Non-Darcian Flow, Kourosh Kianfar, Buddhima Indraratna, Cholachat Rujikiatkamjorn

Buddhima Indraratna

A modified 150 mm Rowe cell equipped with pore water pressure measurement was used to capture the flow relationship during vacuum-assisted radial consolidation. Based on the measured data, a radial consolidation model incorporating the effects of vacuum preloading is proposed, based on a non-linear relationship between the flow velocity and hydraulic gradient. The predictions of the proposed consolidation model are then compared with the predictions based on Hansbo’s Darcian and non- Darcian models. The agreement between the proposed model and the measured data is shown, and the advantages of the proposed model compared with the existing models are discussed. An …


Application Of Vacuum Consolidation For Sustainable Transport Infrastructure, Cholachat Rujikiatkamjorn, Buddhima Indraratna Mar 2014

Application Of Vacuum Consolidation For Sustainable Transport Infrastructure, Cholachat Rujikiatkamjorn, Buddhima Indraratna

Buddhima Indraratna

A system of vertical drains combined with vacuum preloading to accelerate soil consolidation by promoting radial flow is an effective method. In this paper, the analytical modelling of vertical drains incorporating vacuum preloading in an axisymmetric condition is proposed. The distribution of vacuum pressure along the drain and variations in volume compressibility, and permeability of soil based on large scale laboratory observations are included in the proposed solutions. These analytical predictions are compared with a case history taken from Thailand where the entire embankment was stabilised with vertical drains and subjected to vacuum preloading. This analysis employing the writer’s model …