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Articles 1 - 13 of 13
Full-Text Articles in Engineering
Predicted And Observed Behaviour Of Soft Clay Foundations Stabilised With Vertical Drains, Buddhima Indraratna, Wadud Salim, I W Redana
Predicted And Observed Behaviour Of Soft Clay Foundations Stabilised With Vertical Drains, Buddhima Indraratna, Wadud Salim, I W Redana
Buddhima Indraratna
A novel plane strain approach is introduced to model the behaviour of embankment foundations on soft clay stabilised with vertical drains, where the classical axisymmetric solutions are converted to an equivalent plane strain model, incorporating the effects of smear and well resistance. This paper describes the behaviour of an embankment stabilised with vertical drains, where a specific case history is selected from Malaysia. The consolidation of soft clay is modelled on the basis of the modified Cam-clay. The settlement behaviour at various stages of embankment loading is analysed using the finite element technique, and the numerical results are compared with …
Experimental Investigations Into Subballast Filtrations Behaviour Under Cyclic Conditions, Laricar Dominic Ortega Trani, Buddhima Indraratna
Experimental Investigations Into Subballast Filtrations Behaviour Under Cyclic Conditions, Laricar Dominic Ortega Trani, Buddhima Indraratna
Buddhima Indraratna
In rail track environments the loading system is cyclic unlike the monotonic seepage force that usually occurs in embankment dams. The mechanisms of filtration, interface behaviour and time-dependent changes of the drainage and filtration properties occurring within the filter medium require further research to improve the design guidelines. A novel cyclic process simulation filtration apparatus was designed and commissioned at the University of Wollongong, and a standard testing procedure was established. The test apparatus was designed to simulate heavy haul train operations. Key parameters that influence the change in porosity and pore water pressure within the sub ballast layer under …
The Behaviour Of Ballasted Track Foundations: Track Drainage And Geosynthetic Reinforcement, Buddhima Indraratna, Sanjay Nimbalkar, Nayoma Chulani Tennakoon
The Behaviour Of Ballasted Track Foundations: Track Drainage And Geosynthetic Reinforcement, Buddhima Indraratna, Sanjay Nimbalkar, Nayoma Chulani Tennakoon
Buddhima Indraratna
Ballasted Rail tracks are widely used throughout the world due to its resiliency to the repeated wheel loads, low construction cost and ease of maintenance. However, the ballast layer needs periodic maintenance due to its deformation and degradation associated with particle breakage and fouling. A proper understanding of the contamination due to various types of fines and its implications on track drainage is a pre-requisite for effective implementation of track maintenance operations. A new parameter Void Contaminant Index (VCI) can accurately assess the contamination as it includes the effect of void ratio, specific gravity and gradation of ballast and fouling …
Dem Simulation Of Effect Of Confining Pressure On Ballast Behaviour, P K. Thakur, Buddhima Indraratna, Jayan Sylaja J S Vinod
Dem Simulation Of Effect Of Confining Pressure On Ballast Behaviour, P K. Thakur, Buddhima Indraratna, Jayan Sylaja J S Vinod
Buddhima Indraratna
In this paper, an attempt has been made to investigate the influence of confining pressure on deformation and degradation behaviourof railway ballast using the Discrete Element Method (DEM). A novel approach has been employed to model the two dimensionalprojection of field size ballast particles as cluster of bonded particles. Bonded particles are held together by a bond, and debonding isconsidered as particle breakage. A series of cyclic loading simulations using DEM were carried out on an assembly of angular ballast particles at different confining pressures (10 kPa to 240 kPa). The results highlight that the development of axial strain during …
Modeling Of Bolted Joint Behaviour Under Constant Normal Stiffness Conditions - Laboratory Study, Buddhima Indraratna, Najdat I. Aziz, A Dey
Modeling Of Bolted Joint Behaviour Under Constant Normal Stiffness Conditions - Laboratory Study, Buddhima Indraratna, Najdat I. Aziz, A Dey
Buddhima Indraratna
The shear behaviour of grouted joints has been studied in the recent past using the conventional direct shear apparatus, where the normal load on the joint plane is kept constant during testing. The Constant Normal Stiffness (CNS) condition is adopted in this study of shear behaviour of bolted joints, as the CNS condition represents a better approximation of the deformation behaviour of grouted joints in underground excavations as compared to the conventional Constant Normal Load (CNL) condition. A series of tests were conducted to study the behaviour of these stabilised joints under constant normal stiffness condition at an initial normal …
Numerical Prediction Of Vadose Zone Behaviour Influenced By Vegetation, Buddhima Indraratna, Behzad Fatahi, Mohammad Hadi Khabbaz
Numerical Prediction Of Vadose Zone Behaviour Influenced By Vegetation, Buddhima Indraratna, Behzad Fatahi, Mohammad Hadi Khabbaz
Buddhima Indraratna
Bioengineering aspects of native vegetation are currently, and rapidly, being evolved to improve soil stiffness, slope stabilisation, and erosion control. Apart from the reinforcement effect, tree roots establish sufficient matric suction to increase the shear strength and stiffness of the soil. This paper looks at the way, vegetation influences soil matric suction, shrinkage, and ground settlement. A mathematical model for the rate of root water uptake that considers ground conditions, type of vegetation and climatic parameters, has been developed. Based on this proposed model, the distribution of moisture and the matric suction profile adjacent to the tree are numerically analysed. …
Experimental And Numerical Modeling Of Shear Behaviour Of Rock Joints, Buddhima Indraratna, A Haque
Experimental And Numerical Modeling Of Shear Behaviour Of Rock Joints, Buddhima Indraratna, A Haque
Buddhima Indraratna
The shear behaviour of soft rock joints is investigated in laboratory under both Constant Normal Load (CNL) and Constant Normal Stiffness (CNS) conditions. The laboratory behaviour is modelled numerically using the Universal Distinct Element Code (UDEC). The predicted shear stress, normal stress and dilation behaviour with shear displacements are compared with the laboratory results. It is observed that UDEC can predict the peak shear stress of unfilled joints under CNS, however, it overestimates the joint dilation as well as the normal stress. The maximum peak shear stress in UDEC is attained at a greater shear displacement in contrast to the …
Internal Erosional Behaviour Of Lignosulfonate Treated Dispersive Clay, J S. Vinod, Buddhima Indraratna, M A. A Mahamud
Internal Erosional Behaviour Of Lignosulfonate Treated Dispersive Clay, J S. Vinod, Buddhima Indraratna, M A. A Mahamud
Buddhima Indraratna
Internal erosional behaviour of lignosulfonate treated dispersive clay has been studied using the Process Simulation Apparatus for Internal Crack Erosion (PSAICE) designed and built at UOW. Effectiveness of lignosulfonate treated dispersive clay on the erosion resistance has been investigated and its advantage over traditional admixtures is presented. Test results show that the hydraulic shear stress increases with increase in the amount of lignosulfonate. In addition, the micro-chemical analysis has been carried out using FTIR. Based on the Fourier Transform Infrared (FTIR) Spectroscopy results a stabilization mechanism has been proposed for lignosulfonate treated dispersive soil.
Human Behaviour Recognition With Segmented Inertial Data, Chao Sun, David A. Stirling, Fazel Naghdy
Human Behaviour Recognition With Segmented Inertial Data, Chao Sun, David A. Stirling, Fazel Naghdy
Professor Fazel Naghdy
The development and recent advancements of integrated inertial sensors has afforded substantive new possibilities for the acquisition and study of complex human motor skills and ultimately their imitation within robotic systems. This paper describes continuing work on kinetic models that are derived through unsupervised learning from a continuous stream of signals, including Euler angles and accelerations in three spatial dimensions, acquired from motions of a human arm. An intrinsic classification algorithm, MML (Minimum Message Length encoding) is used to segment the complex data, formulating a Gaussian Mixture Model of the dynamic modes it represents. Subsequent representation and analysis as FSM …
Sensitization Behaviour Of 11-12% Cr Aisi 409 Stainless Steel During Low Heat Input Welding, Cornelis Janise Van Niekerk, Madeleine Du Toit
Sensitization Behaviour Of 11-12% Cr Aisi 409 Stainless Steel During Low Heat Input Welding, Cornelis Janise Van Niekerk, Madeleine Du Toit
Faculty of Engineering and Information Sciences - Papers: Part A
The study comprised of the investigation into the sensitization characteristics of AISI 409 titanium stabilized ferritic stainless steel during low heat input welding. AISI 409 is a fully ferritic stainless steel used in catalytic converters and tubing for automotive exhaust systems due to the supposition that sensitization does not occur during low heat input welding. Two plates of 2 and 4 mm were tested for sensitization during low heat input welding. The study confirmed that chromium carbide (M23C6) precipitation occurs on the grain boundaries in the heat-affected zone with consequent depletion of Cr adjacent to the …
Cyclic Behaviour Of Soft Soil Subgrade Improved By Prefabricated Vertical Drains, Buddhima Indraratna, Cholachat Rujikiatkamjorn, Jing Ni
Cyclic Behaviour Of Soft Soil Subgrade Improved By Prefabricated Vertical Drains, Buddhima Indraratna, Cholachat Rujikiatkamjorn, Jing Ni
Faculty of Engineering - Papers (Archive)
The behaviour of saturated soft clays subjected to cyclic loading is of considerable importance in the design of railway subgrades. Soft clays can be extensively found in many coastal regions of Australia up to significant depths, including the coastal belt and the central part of NSW. These soft clay deposits are characterised by very low bearing capacity and excessive settlement. The increase in generated excess pore pressures due to heavy freight trains significantly reduces the bearing capacity and causes serious damage to the rail infrastructure such as clay pumping underneath railway tracks and excessive subsidence. The use of prefabricated vertical …
Influence Of Coke Ash On Blast Furnace Hearth Behaviour, M W. Chapman, Robert J. Nightingale, B J. Monaghan
Influence Of Coke Ash On Blast Furnace Hearth Behaviour, M W. Chapman, Robert J. Nightingale, B J. Monaghan
Faculty of Engineering - Papers (Archive)
Abstract Liquid iron in the ironmaking blast furnace picks up more than half of its carbon while percolating through the packed coke bed in the deadman and hearth of the blast furnace thus the conditions within the hearth have a direct impact on liquid drainage and hot metal quality. Consequently, the rate of carbon dissolution into liquid iron, and the factors contributing to the movement of liquids through the coke bed must be understood. Investigations using quenched coke dissolution techniques have demonstrated that a mineral layer was formed between the liquid iron and the coke matrix as coke dissolves into …
The Behaviour Of Carbon Fibre Reinforced Polymer Confined Concrete Cylinders Under High Temperature Exposure, Butje Alfonsius Louk Fanggi, Muhammad N. S Hadi
The Behaviour Of Carbon Fibre Reinforced Polymer Confined Concrete Cylinders Under High Temperature Exposure, Butje Alfonsius Louk Fanggi, Muhammad N. S Hadi
Faculty of Engineering - Papers (Archive)
This study investigates the effect of temperature on the behaviour of concrete cylinders wrapped with Carbon Fibre Reinforced Polymer (CFRP). The study used nine concrete cylinders in three groups; the first group was exposed to room temperature of approximately 20ºC, the second group was exposed to a cyclic temperature with a temperature range of 20ºC to 70ºC, and the third group was exposed to a prolonged temperature of 70ºC. All cylinders were then tested to failure. The study indicated that ultimate strength of cylinders wrapped with one and two layers of CFRP are significantly unchanged after being exposed to 20ºC …