ORCID Profile
0000-0003-1725-7972
Current Organisation
Monash University
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Publisher: Springer International Publishing
Date: 20-11-2022
Publisher: American Society of Civil Engineers (ASCE)
Date: 2010
Publisher: Elsevier BV
Date: 09-2023
Publisher: Thomas Telford Ltd.
Date: 08-2010
DOI: 10.1680/GRIM.2010.163.3.149
Abstract: Hydrated lime, activated fly ash and activated slag have been used to stabilise a number of soils collected from a range of locations across Australia. This paper explores the reaction mechanics of soils and industrial by-products in the role of stabilisation. Scanning electron microscopy and X-ray diffractometry analyses on stabilised soils were carried out after various curing periods. Based on the extensive study of the microstructural and mineralogical developments, it was found that the soil microstructure undergoes dramatic changes during the modification and stabilisation processes. The different stabilising agents were also shown to have influenced the nature and form of developing microstructural elements. The slag particles were subjected to significant surficial transformation, whereas fly ash relied exclusively on through-solution mechanisms, and was comparatively inert under the prevalent conditions. The presence of organic matter in soils was found to interfere with the nucleation and growth of cementitious phases causing slow gain in strength properties. Finally, these results were used to elucidate the development of the geotechnical properties of the stabilised soils in an accompanying paper by the authors (part B).
Publisher: Springer International Publishing
Date: 25-09-2019
Publisher: American Society of Civil Engineers (ASCE)
Date: 10-2010
Publisher: Wiley
Date: 20-12-2010
DOI: 10.1002/NAG.894
Publisher: Canadian Science Publishing
Date: 2014
Abstract: Tensile cracking due to desiccation and fracture properties are of great importance in clay liners, earth dam engineering, waste contaminant systems, and mine tailings. This paper presents restrained shrinkage test results and analyses of consolidated desiccating soil, and compares results with numerical analyses using the computer program Universal Distinct Element Code (UDEC). The cohesive crack method was used as it is more appropriate than linear elastic fracture mechanics for soil cracking at high moisture contents with the likely presence of plasticity during fracture. The variation of the radial stresses on the inner ring with water content was used to model mode I cracking and gather fracture properties of the propagating crack. The model was validated on kaolin clay tested under restrained ring shrinkage and was compared with various test results and results from the literature. The test could be a valuable tool in determining fracture properties during desiccation.
Publisher: Springer Science and Business Media LLC
Date: 08-2022
DOI: 10.1007/S11440-022-01608-3
Abstract: The coexistence of air and water as a mixture in void spaces in unsaturated soils, makes its mechanical behaviour relatively complex and difficult to be addressed by classical saturated soil mechanics principles. In addition, many engineering problems encountered in practical situations had some part to deal with unsaturated soils and therefore the clear understanding of various behavioural patterns of unsaturated soils is crucial. To date, a large number of attempts are reported in evaluating the mechanical behaviour of unsaturated soils in different stress spaces. The present study evaluates the deviatoric behaviour of compacted unsaturated soils in deviator stress–specific water volume–mean net stress ( $$q, {v}_{\\mathrm{w}}, p$$ q , v w , p ) space. The effect of moisture content, confinement and the stress history on the behaviour of compacted unsaturated kaolin subjected to triaxial compression was assessed and the results showed that there exists a critical state surface for compacted unsaturated soils in $$q- {v}_{\\mathrm{w}}- p$$ q - v w - p space.
Publisher: Canadian Science Publishing
Date: 09-2012
DOI: 10.1139/T2012-068
Abstract: Land surface and subsurface variables, such as soil moisture–suction and temperature, are among the most important components to study the behaviour of expansive soil, geothermal energy, and climate change. A more accurate and long-term series of soil moisture and temperature prediction, due to ground–atmosphere interaction, is very important for real-time drought monitoring for understanding and improving the behaviour of soil, buried structures, and climate prediction. In this study, ground–atmosphere interaction is numerically modelled using Vadose/W software for two instrumented sites in Melbourne, Australia. Soil moisture and temperature down to 2 m depth were monitored over 2 years at discrete locations and the meteorological variables including air temperature, air humidity, wind speed, precipitation, and solar radiation were measured from a weather station installed at the sites. Further, laboratory and field tests were performed to establish initial conditions and soil characteristics such as the soil-water characteristic curve (SWCC ), hydraulic conductivity, and thermal conductivity functions. The numerical model results were calibrated with the field data, indicating good agreement between numerical and field results. The calibrated numerical model was used to compute the long-term moisture and temperature variations into the immediate future using the past 20 years of weather data in Melbourne.
Publisher: Elsevier BV
Date: 09-2006
Publisher: Canadian Science Publishing
Date: 08-2201
DOI: 10.1139/T11-031
Publisher: Informa UK Limited
Date: 09-02-2022
Publisher: Wiley
Date: 15-02-2014
DOI: 10.1002/NAG.2253
Publisher: Canadian Science Publishing
Date: 11-2015
Abstract: Field monitoring is an important means for understanding soil behaviour and its interaction with buried structures such as pipeline. This paper details the successful instrumentation of a section of an in-service cast iron water main buried in an area of reactive clay where frequent water pipe breakage has been observed. The instrumentation included measurement of pipe strain pipe water pressure and temperature soil pressure, temperature, moisture content, and matric suction as well as the meteorological conditions on site. The data generally indicated that changes in soil temperature, suction, and moisture content were directly related to the local climatic variations. The suction and moisture content data indicated that the soil profile at the site down to around 700 mm, and probably down to 1000 mm, is affected by changes in surface weather, while soil conditions below this depth appear to be more stable. Analysis of pipe strain indicated that the pipe behaves like a cantilever beam, with the top experiencing predominantly tensile strains during summer. Subsequently, these trends reduce to compressive strains as soil swelling occurs because of the increase of moisture content with the onset of winter.
Publisher: Springer International Publishing
Date: 20-11-2022
Publisher: Elsevier BV
Date: 02-2022
Publisher: Springer International Publishing
Date: 20-11-2022
Publisher: American Society of Civil Engineers (ASCE)
Date: 08-2015
Publisher: Informa UK Limited
Date: 03-2005
Publisher: Research Publishing Services
Date: 2013
Publisher: Springer Science and Business Media LLC
Date: 24-11-2011
Publisher: Informa UK Limited
Date: 29-12-2023
Publisher: Springer International Publishing
Date: 20-11-2022
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2023
Publisher: American Society of Civil Engineers (ASCE)
Date: 12-2005
Publisher: American Society of Civil Engineers (ASCE)
Date: 12-2005
Publisher: Canadian Science Publishing
Date: 08-2011
DOI: 10.1139/T11-036
Publisher: Thomas Telford Ltd.
Date: 05-2006
DOI: 10.1680/COMA.2006.159.2.67
Abstract: This paper investigates the significant curling that occurs during drying of crushed basaltic aggregate stabilised with cementitious binders. The percentage of cement (by weight) is 3%, producing stabilised materials, which are weakly cemented. These materials are commonly used in the pavement industry for constructing cement-stabilised pavements for light to medium traffic. Curling deformations, in the form of lifting off from the edges (generating a concave surface), or lifting off from the middle (creating a convex surface), are reported in drying concrete pavements. The test specimens had cross-sections measuring 75 mm × 75 mm and length of 280 mm. This paper presents experimental observations of differences in shrinkage behaviour of stabilised crushed rock drying from one or all faces (i.e. one- or three-dimensional conditions) under controlled conditions. A theoretical explanation for the perceived curling is presented on the basis of physical principles and unsaturated soil mechanics. The curling was attributed primarily to differential shrinkage strain increments that occur within the specimen and their variation with the progression of desiccation. Making use of non-linear elasticity theory, the shrinkage and curling behaviour was modelled using the finite-difference method.
Publisher: American Society of Civil Engineers (ASCE)
Date: 05-2016
Publisher: American Society of Civil Engineers (ASCE)
Date: 06-2016
Publisher: Informa UK Limited
Date: 30-09-2022
Publisher: Trans Tech Publications, Ltd.
Date: 06-2013
DOI: 10.4028/WWW.SCIENTIFIC.NET/KEM.558.424
Abstract: Health monitoring of civil infrastructure systems has recently emerged as a powerful tool for condition assessment of infrastructure performance. With the widespread use of modern telecommunication technologies, structures could be monitored periodically from a central station located several kilometres away from the field. This remote capability allows immediate damage detection, so that necessary actions are taken to reduce the risk. Optical fiber sensors offer a relatively new technology for monitoring the performance of spatially distributed structures such as pipelines. In this regards, several commercially available strain and temperature sensing equipment such as discrete FBGs (Fibre Bragg Gratings) and fully distributed sensing techniques such as Raman DTS (distributed temperature sensor) and Brillouin Optical Time Domain Reflectometry (BOTDR) typically offer sensing lengths of the order of 100 km's. Distributed fiber optic sensing offers the ability to measure temperatures and/or strains at thousands of points along a single fiber. In this paper, the authors will give a brief overview of these optical fiber technologies, outline potential applications of these technologies for geotechnical engineering applications and experience in utilising BOTDR in water pipeline monitoring application.
Publisher: Informa UK Limited
Date: 14-04-2023
Publisher: American Society of Civil Engineers (ASCE)
Date: 08-2011
Publisher: Springer Science and Business Media LLC
Date: 05-11-2016
Publisher: Thomas Telford Ltd.
Date: 06-2013
Abstract: This paper examines the performance of unsaturated soils under repeated loading. As part of the research, a triaxial system was developed that incorporates small-strain measurements using Hall effect transducers, in addition to suction measurements taken using a psychrometer. Tests were conducted on s les of kaolin under constant water mass conditions. The results address the effects of compaction effort and water content at the time of compaction on the overall performance of unsaturated soils, under different litudes of loading and different confining pressures. The results show that suction in the s le reduced with increasing number of loading cycles of the same magnitude. The resilient modulus initially increased with increasing water content up to approximately optimum water content, and then reduced substantially with further increase in water content.
Publisher: Canadian Science Publishing
Date: 03-2014
Abstract: Measurement of the moisture variation in soils is required for geotechnical design and research because soil properties and behavior can vary as moisture content changes. The neutron probe, which was developed more than 40 years ago, is commonly used to monitor soil moisture variation in the field. This study reports a full-scale field monitoring of soil moisture using a neutron moisture probe for a period of more than 2 years in the Melbourne (Australia) region. On the basis of soil types available in the Melbourne region, 23 sites were chosen for moisture monitoring down to a depth of 1500 mm. The field calibration method was used to develop correlations relating the volumetric moisture content and neutron counts. Observed results showed that the deepest “wetting front” during the wet season was limited to the top 800 to 1000 mm of soil whilst the top soil layer down to about 550 mm responded almost immediately to the rainfall events. At greater depths (550 to 800 mm and below 800 mm), the moisture variations were relatively low and displayed predominantly periodic fluctuations. This periodic nature was captured with Fourier analysis to develop a cyclic moisture model on the basis of an analytical solution of a one-dimensional moisture flow equation for homogeneous soils. It is argued that the model developed can be used to predict the soil moisture variations as applicable to buried structures such as pipes.
Publisher: Elsevier BV
Date: 21
Publisher: Elsevier BV
Date: 03-2016
Publisher: Thomas Telford Ltd.
Date: 08-2010
DOI: 10.1680/GRIM.2010.163.3.165
Abstract: The use of industrial by-products in the stabilisation of problematic soils presents economic, environmental and social benefits. The geotechnical and physico-chemical behaviour of some Australian clayey soils of contrasting mineralogy stabilised with commonly employed industrial by-products has been investigated in the laboratory for developments in pH, plasticity, and undrained shear strength at curing periods of up to 1 year. Stabilising agents including hydrated lime, fly ash and ground granulated blastfurnace slag (‘slag') were utilised. The results of this study showed that soils mixed to moisture contents well above their respective liquid limits developed substantial undrained shear strength directly upon exposure to cementitious stabilisers and continued to gain significant strength thereafter. It is noteworthy that s les treated with slag activated with hydrated lime gained more strength at shorter periods of curing than comparable s les of activated fly ash and s les simply treated with equivalent proportions of hydrated lime. The pH measurements gave an indication of cementitious activity that was closely aligned to the development of undrained shear strength, where a reducing pH was observed to consistently coincide with gains in strength. Plasticity tests indicated that smectite-dominant soils have a reduction in plasticity index, while kaolinite-dominant soils have an increase in plasticity index as strong inter-particle bonds are formed. This study also found that organic matter obstructed cementitious activity. The underlying micromechanical aspects related to geotechnical response have been detailed in an accompanying paper by the authors (part A).
Publisher: Elsevier BV
Date: 09-2015
Publisher: ASTM International
Date: 09-2012
DOI: 10.1520/GTJ104271
Publisher: Canadian Science Publishing
Date: 06-2002
DOI: 10.1139/T02-003
Abstract: Chemical compatibility tests using hydraulic conductivity testing with chemical permeants are normally undertaken to assess the integrity of compacted clayey liners used for waste containment. This paper highlights the fact that current routine methods of flexible wall and rigid wall testing techniques fail to represent the zero lateral strain boundary condition that is required to realistically represent the field situation. The test results indicate that flexible wall permeameters underestimate the likely increases in hydraulic conductivity due to chemicals, while the rigid wall permeameters can severely overestimate these effects. A new test technique, which incorporates the zero lateral strain condition in a simple manner, is presented. This technique involves the use of a rigid wall concept in a flexible wall permeameter. A split rigid mould is used to encase the soil specimen that is glued to the internal surfaces of the mould, to apply the zero lateral strain boundary condition. The new technique is shown to be suitable for both chemical compatibility and desiccation testing. The tests were undertaken with varying concentrations of saline water, methanol, and landfill leachate. The test results indicate that the new technique produces results that fall between the results obtained from flexible wall and rigid wall permeameters. It is argued that the new test technique provides a more rational approach for chemical compatibility testing than the current rigid wall and flexible wall techniques.Key words: soil, hydraulic conductivity, chemical compatibility, landfill, permeameter, boundary condition.
Publisher: American Society of Civil Engineers (ASCE)
Date: 07-2009
Publisher: Elsevier BV
Date: 05-2015
Publisher: CRC Press
Date: 05-06-2014
DOI: 10.1201/B17034-29
Publisher: Springer Science and Business Media LLC
Date: 04-02-2022
Publisher: Thomas Telford Ltd.
Date: 2013
DOI: 10.1680/GEOT.9.P.105
Abstract: This paper elucidates some of the controlling factors governing soil desiccation. The desiccation tests were conducted on three materials – clay, potato starch and milled quartz sand – all three featuring similar fracture energy. Two controlling factors were identified in desiccation cracking, regardless of the material. The first is the tensile stress and strain energy development within the material when the material is restrained against shrinkage. The distribution of the tensile stress will depend on the boundary conditions and material stiffness, and will dictate where cracks are likely to originate. The second factor is that the exact positions of crack initiations will be controlled by the flaws and/or pores within the material. For materials such as clay, with very fine particles, the cracking mechanism is governed by flaws, since the desaturation of fine pores would require very high suction stress, and this requirement leads to sequential cracking and orthogonal crack patterns. If the material has particles giving relatively large and uniform pore sizes with high moisture diffusivity leading to high shrinkage energy prior to cracking, then the fracture energy balance indicates that cracking can occur in near hexagonal patterns with 120° crack initiations, which occur predominantly simultaneously. However, even for materials with lower moisture diffusivity, such as for clay, high desiccation rates can give rise to an ‘effective layer' over which high suctions and strain energy develop, leading to almost simultaneous dense cracking.
Publisher: Canadian Science Publishing
Date: 11-2012
DOI: 10.1139/T2012-084
Abstract: Volumetric behaviour is a fundamental consideration in unsaturated soil constitutive modelling. It is more complex than when the soil is saturated, as unsaturated soils exhibit a range of responses such as swelling and collapse under wetting and shrinkage and cracking during drying. While significant advances have been made, it is still difficult to generally explain all patterns of behaviour. This paper presents a new framework for modelling volumetric response of unsaturated soils with emphasis on compacted soils. The framework uses void ratio (e), moisture ratio (e w ), and net stress (p) as the main constitutive variables and suction as a dependent variable. This choice of e w as a main constitutive variable is theoretically sound and is more attractive than the use of suction, which is relatively difficult to measure and displays significant hysteresis during drying and wetting. The framework incorporates the well-known compaction curve making it easily applicable to practical situations. Within the overall e–e w –p space, the operative space is constrained by three main surfaces namely, loading–wetting state boundary surface, tensile failure surface, and the saturated plane. The conceptual basis for these state surfaces is described and the framework is qualitatively validated against observed behaviour of compacted soils.
Publisher: ASME International
Date: 05-2012
DOI: 10.1115/1.4007540
Abstract: Based on the concept of an energy pump, water transportation in a carbon nanotube (CNT) is studied by molecular dynamics simulations. The influences of CNT pretwist angle, water mass, environmental temperature, CNT diameter, CNT channel length, and CNT channel restrain condition on driving force and transportation efficiency are investigated. It is found that in order to initiate the transportation, the pretwist angle must be larger than certain threshold, 80 deg, for the case of one water molecule in a restrained (8,0) CNT. Furthermore, driving force decreases with increasing water mass and it is more efficient to transport multiple water molecules than one water molecules. The water molecule is found to have higher degrees of collisions in a (8,0) CNT in elevated environmental temperature. By comparing three CNT channel lengths, the channel length of 19.80 nm is identified as a faster and more efficient transporter in an unrestrained (8,8) CNT. Finally, molecular dynamics (MD) simulation indicates that a water molecule can only be transported below 300 K in an unrestrained (8,8) CNT due to the large friction caused by severely deformed channel and the Brownian motion.
Publisher: Springer International Publishing
Date: 17-09-2022
Publisher: Informa UK Limited
Date: 16-05-2022
Publisher: Elsevier BV
Date: 08-2023
Publisher: ASTM International
Date: 04-02-2015
DOI: 10.1520/GTJ20140233
Publisher: Elsevier BV
Date: 06-2022
DOI: 10.1016/J.JENVMAN.2022.114926
Abstract: Expansive clays are found in many countries worldwide, and they exhibit inherent volume change during the seasonal moisture variation causing cracks, heaves, and damages to the overlying pavements. Chemical stabilisation is one of the most used approaches to treat the expansive clay subgrades. Cement, Lime and Fly ash are the most commonly used stabilisers, in which fly is cheaper and a by-product obtained from the coal power plant. This paper reviews fly ash stabilisation on various clay types, including low plasticity clays, high plasticity clays, silty clays, organic clays, and peats. The review begins with the properties of fly ash, followed by the characteristics of fly ash stabilised subgrades. The micro-level mechanism, physical, mechanical, and hydraulic characteristics of stabilised pavements are presented graphically for the Class C, and F fly ashes. The micro-level studies reveal that the pozzolanic reaction is stronger than the cation exchange during the fly ash stabilisation. The unconfined compressive strength (UCS), California bearing ratio (CBR) and resilient modulus (M
Publisher: Springer Science and Business Media LLC
Date: 07-12-2021
Publisher: American Society of Civil Engineers (ASCE)
Date: 12-2004
Publisher: Canadian Science Publishing
Date: 08-2002
DOI: 10.1139/T02-036
Abstract: Laboratory hydraulic conductivity tests are commonly used for the design of clayey liners in waste containment. Although relatively small hydraulic gradients are encountered under field conditions, elevated gradients are desirable to reduce the testing time. It is generally believed, however, that these elevated gradients would reduce the conductivity measured owing to specimen consolidation. In the current paper a theoretical analysis is presented for assessing the effect of specimen consolidation. The theoretical results were compared with experimental results obtained for two local soils. Parametric analyses and nondimensional analyses were carried out and the results are presented. It was found that the hydraulic conductivity is dependent on the type of permeameter, the form of gradient application, and the state of stress within the soil. It was apparent that hydraulic conductivity can decrease with an increase in the hydraulic gradient, and the decrease was not significant up to a hydraulic gradient of about 300 for the soils tested.Key words: hydraulic conductivity, hydraulic gradient, specimen consolidation, volume change, permeameter.
Publisher: Thomas Telford Ltd.
Date: 12-2015
Abstract: Because of climate change and increasing population in Australia–New Zealand, several key environmental geotechnics issues are emerging. These key issues include the impact of climate change, depletion of natural resources, interest in the use of recycled materials, advances in seeking new energy sources, disaster waste management as well as other sustainability issues. Evaluation of climate change effects, adaptation technologies and interdisciplinary solutions for geo-infrastructure and other key issues and challenges will be discussed in this paper.
Publisher: Elsevier BV
Date: 02-2011
Publisher: No publisher found
Date: 2011
Publisher: Elsevier BV
Date: 2017
Publisher: Thomas Telford Ltd.
Date: 09-2013
Abstract: The numerical modelling of a field desiccation experiment carried out in Saint Alban, Canada is attempted. The progression of cracks during the course of desiccation and most material properties relevant to the modelling have been reported in detail in the published literature. The numerical model is based on the cohesive crack approach using a distinct-element program. The model seeks to replicate the crack pattern obtained in a linear section of the experiment. The development of the primary crack network is modelled successfully. The methodology shown in the paper can be used for numerical modelling of field desiccation.
Publisher: Elsevier BV
Date: 2016
Publisher: ASTM International
Date: 2004
DOI: 10.1520/GTJ11767
Publisher: Elsevier BV
Date: 02-2017
Publisher: American Society of Civil Engineers (ASCE)
Date: 06-2013
Publisher: Springer Nature Singapore
Date: 24-11-2022
Publisher: American Society of Civil Engineers
Date: 16-05-2011
DOI: 10.1061/47628(407)32
Publisher: American Society of Civil Engineers (ASCE)
Date: 08-2005
Publisher: ASTM International
Date: 17-11-2015
DOI: 10.1520/GTJ20130131
Publisher: American Society of Civil Engineers
Date: 16-05-2011
DOI: 10.1061/47628(407)31
Publisher: Elsevier BV
Date: 02-2017
Publisher: American Society of Civil Engineers (ASCE)
Date: 02-2006
Publisher: Institute of Electrical and Electronics Engineers (IEEE)
Date: 2022
Publisher: Wiley
Date: 06-04-2015
DOI: 10.1002/NAG.2380
Publisher: Elsevier BV
Date: 03-2012
Publisher: Springer Science and Business Media LLC
Date: 12-2006
Publisher: Elsevier BV
Date: 06-2013
Publisher: Elsevier BV
Date: 11-2011
No related grants have been discovered for Jayantha Kodikara.