Dr George Kouretzis
School of Engineering (Civil Engineering)
- Phone:(02) 4921 6449
Bridging the gap
Dr George Kouretzis and his colleagues work towards bridging the gap between research, engineering applications and public benefit, particularly in the area of onshore pipeline networks, the circulatory lifelines of modern society.
Motivated by the challenges he faced during his involvement in the design of buried pipelines in problematic areas, Kouretzis' research focuses on increased safety levels and uninterrupted operation of pipeline infrastructure, from mega gas pipelines to local water distribution networks.
Kouretzis and his group examine the behaviour of pipelines crossing soil deposits that are sensitive to environmental and climate change effects, areas susceptible to mine subsidence, or zones of high seismicity. They also investigate the impact of new developments on existing networks, and the detrimental effects that an accidental blast or a terrorist attack may have on a critical lifeline. The goal of all these studies is the same: to understand how onshore pipeline infrastructure will perform under the influence of these natural or anthropogenic hazards, under which circumstances there is a significant risk of failure, and which measures practicing engineers must take to mitigate the probability and the consequences of this failure.
The outcome of these studies is a compilation of practical design tools, charts and simple computer codes that can be readily used by pipeline engineers in their current and future projects. Kouretzis has collaborated with a number of consulting companies in implementing the findings of this research in critical projects, such as the design of high-pressure natural gas pipelines crossing active seismic faults. New construction techniques have been adopted from the insight gained on pipeline behaviour, and these tools are now endorsed by international guidelines on the design of buried pipelines, superseding earlier methods proposed in the 70s and 80s.
Recently, the Australian Research Council awarded a grant to a team to be led by Kouretzis to further delve into the effects of environmental changes on onshore pipelines, with a particular focus on Australian conditions. This 3-year project commencing in 2015 will include the development of a custom-built laboratory apparatus to investigate how buried pipelines interact with their surrounding soil. The team is collaborating with a number of international groups working in the same field, and their long-term aim is to create a national buried pipeline research hub at the University of Newcastle.
Kouretzis obtained a Diploma in Civil Engineering from the Democritus University of Thrace, Greece, and received his MSc and PhD from the School of Civil Engineering of the National Technical University of Athens (NTUA), Greece, in 2005. In the following years, he continued his engagement with NTUA's School of Civil Engineering, first as a post-doctoral researcher and later as a part-time lecturer. After a four-year period where he was primarily engaged with industry-related activities, George joined the University of Newcastle and the Centre of Excellence for Geotechnical Science and Engineeringin 2012 and currently holds a senior lecturer position in the School of Engineering.
In parallel with his research on buried pipelines, Kouretzis is working on various problems in the areas of soil-structure interaction, computational geomechanics, geotechnical earthquake engineering and soft soil testing techniques. He has published over 35 papers in monographs, refereed journals and peer-reviewed conference proceedings on the analysis of buried pipelines affected by geohazards, the aseismic design of tunnels and the numerical simulation of large deformation problems in geomechanics. His research has attracted substantial funding from government as well as industry sources, and he has been involved in several projects as project leader and chief investigator. Kouretzis also serves as associate editor of Canadian Geotechnical Journal and as guest editor of Australian Geomechanics. He is also an active reviewer for a number of international journals, and member of the review panel of international funding bodies.
Parallel to his academic activities, since 2000 Dr Kouretzis has been involved as an expert engineering consultant in a series of major energy and transportation infrastructure projects, including high- and medium-pressure natural gas and crude oil pipeline networks, bridges and motorway tunnels in areas of high seismicity, critical runway embankments etc. He is also an active member of the Australian Geomechanics Society, and currently serves as secretary of its NSW-Newcastle Chapter.Finally, Kouretzis is the recipient of a number of awards for research and teaching excellence from organisations including the International Association for Computer Methods and Advances in Geomechanics and the Australian Association of Computational Mechanics
George (Georgios) Kouretzis obtained a diploma in Civil Engineering from the Democritus University of Thrace, Greece and received his MSc and PhD from the School of Civil Engineering of the National Technical University of Athens (NTUA), Greece in 2005. In the following years, he continued his engagement with the School of Civil Engineering, NTUA first as a post-doctoral researcher and then as a part-time lecturer. His research interests include numerical simulation of dynamic soil-structure interaction effects under cyclic loading, analytical and numerical methods to assess pipeline and tunnel performance under transient and permanent ground displacements, design of protective structures to resist conventional weapons effects, numerical simulation of moving boundary problems in geomechanics, and evaluation of soil and topography effects on strong earthquake ground motion. Parallel to his research activities, he has been involved since 2000 as an engineering consultant and as an auditor in a series of major energy and transportation infrastructure projects, including high- and medium-pressure natural gas and crude oil pipeline networks, bridges and motorway tunnels in areas of high seismicity, critical runway embankments etc. He has published over 30 papers in monographs, refereed journals and peer-reviewed conferences, and serves as an active reviewer for a number of international journals.Research Expertise
Oriented towards the following four fields, lying in the areas of geotechnical earthquake engineering, dynamic response of structures and computational geomechanics: - Evaluation of soil and topography effects on strong earthquake ground motion, - Soil-structure interaction under earthquake and blast loading, - Aseismic design of underground structures under transient and permanent ground displacements, - Design of protective structures to resist conventional weapons effects, and - Moving boundary problems in geomechanics.
- Geotechnical and Geoenvironmental Engineering: soil investigation methods and in situ testing, analysis and design of shallow and deep foundations, soil and groundwater contamination and remediation techniques, application of numerical methods in geotechnical engineering problems. - Geotechnical Earthquake Engineering; aseismic design of pipelines and tunnels, mitigation of liquefaction effects on structures, seismic slope stability, assessment of soil effects and microzonation studies, seismic design of retaining walls. - Foundation Engineering; Analysis and design of flexible retaining walls, soil anchors, methods for soil improvement.
He has been a member of research groups of the School of Civil Engineering and of the School of Mining and Metallurgical Engineering, National Technical University of Athens Greece, as well as of the National and Kapodistrian University of Athens.
- PhD (Geotechnical Engineering), National Technical University of Athens - Greece
- Diploma of Civil Engineering, Democritus University of Thrace - Greece
- Master of Science (Engineering), National Technical University of Athens - Greece
- Dynamic response of structures
- Foundation engineering
- Geotechnical earthquake engineering
- Numerical and analytical methods in geomechanics
- Soil and topography effects on strong ground motion
- Soil-structure interaction
Fields of Research
|090501||Civil Geotechnical Engineering||85|
|Title||Organisation / Department|
|Senior Lecturer||University of Newcastle
School of Engineering
|Dates||Title||Organisation / Department|
|1/01/2008 - 1/09/2008||Casual Academic||National Technical University of Athens
|1/07/2005 - 1/01/2008||Research Assistant||National Technical University of Athens
For publications that are currently unpublished or in-press, details are shown in italics.
Book (1 outputs)
Yiouta-Mitra P, Kouretzis G, Bouckovalas G, Sofianos A, Effect of underground structures in earthquake resistant design of surface structures (2007) [A3]
This research deals with the question of whether, and under what circumstances, the presence of underground structures should be taken into account for the earthquake resistant de... [more]
This research deals with the question of whether, and under what circumstances, the presence of underground structures should be taken into account for the earthquake resistant design of neighbouring surface structures. In order to investigate the effect of underground structures on surface seismic motion, a series of dynamic plane-strain numerical analyses were conducted, considering a circular tunnel embedded in a viscoelastic half-space, and a harmonic SV-wave excitation. The numerical methodology, based on the Finite Difference Method, aims at quantifying the effect of the soil medium characteristics, excitation frequency, tunnel diameter, depth of construction, and relative flexibility of the lining compared to that of the surrounding soil. Conclusions contain preliminary criteria identifying the cases when the presence of an underground structure should be considered in the design of a surface structure. Copyright ASCE 2007.
Chapter (1 outputs)
Kouretzis G, Ansari Y, Pineda JA, Sheng D, 'Simulation of extreme deformation problems in viscoplastic strain-softening clays with the coupled Eulerian-Lagrangian method.', Jubilee Volume: in honour to Prof. Andreas Anagnostopoulos, National Technical University of Athens Press, Athens, Greece 309-322 (2015)
Journal article (23 outputs)
Liu H, Zheng C, Ding X, Kouretzis GP, Sloan SW, 'A revised solution for the horizontal vibration of an end-bearing pile in viscoelastic soil', International Journal for Numerical and Analytical Methods in Geomechanics, (2016)
Â© 2016 John Wiley & Sons, Ltd.. This note presents a new method to derive closed-form expressions describing the horizontal response of an end-bearing pile in viscoelastic soil s... [more]
Â© 2016 John Wiley & Sons, Ltd.. This note presents a new method to derive closed-form expressions describing the horizontal response of an end-bearing pile in viscoelastic soil subjected to harmonic loads at its head. The soil surrounding the pile is assumed as a linearly viscoelastic layer. The propagation of waves in the soil and pile is treated mathematically by three-dimensional and one-dimensional theories, respectively. Unlike previous studies of the problem, the formulation presented allows the governing equations of the soil to be solved directly, eliminating the need to introduce potential functions. Accordingly, the dynamic response of the pile is obtained by means of the initial parameter method, invoking the requirement for continuity at the pile-soil interface. It is demonstrated that the derived compact solution matches exactly an existing solution that utilises potential functions to formulate the problem. Copyright
Kouretzis GP, Karamitros DK, Sloan SW, 'Analysis of buried pipelines subjected to ground surface settlement and heave', CANADIAN GEOTECHNICAL JOURNAL, 52 1058-1071 (2015) [C1]
Zheng C, Liu H, Kouretzis GP, Sloan SW, Ding X, 'Vertical response of a thin-walled pipe pile embedded in viscoelastic soil to a transient point load with application to low-strain integrity testing', Computers and Geotechnics, 70 50-59 (2015) [C1]
Â© 2015 Elsevier Ltd. This paper presents an analytical method to compute the dynamic response of a thin-walled pipe pile due to a vertical transient point load acting on its head... [more]
Â© 2015 Elsevier Ltd. This paper presents an analytical method to compute the dynamic response of a thin-walled pipe pile due to a vertical transient point load acting on its head. Inspired from challenges faced during the interpretation of low-strain integrity tests on pipe piles, the proposed method moves beyond the widely used one-dimensional wave theory to consider the asymmetric nature of the problem, and stress wave propagation along both the vertical and circumferential directions. Coupling of pipe pile-viscoelastic soil vibration is considered via modeling the outer and inner soil as a series of infinitesimally thin layers in perfect contact with the pile, and their low-strain properties are directly introduced in the solution. The methodology is validated against numerical results, before discussing the mechanisms governing the dynamic response of the pipe pile-soil system to the impact load, with emphasis on the vertical velocity measured at a hypothetical receiver placed on the pile head. Additional results from a parametric analysis are used to provide insights on the accurate estimation of the arrival time of the receiving wave, and the optimal location of the receiver.
Zhang X, Sheng D, Kouretzis GP, Krabbenhoft K, Sloan SW, 'Numerical investigation of the cylinder movement in granular matter', Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 91 (2015) [C1]
Â© 2015 American Physical Society. We investigate numerically the mechanisms governing horizontal dragging of a rigid cylinder buried inside granular matter, with particular empha... [more]
Â© 2015 American Physical Society. We investigate numerically the mechanisms governing horizontal dragging of a rigid cylinder buried inside granular matter, with particular emphasis on enumerating drag and lift forces that resist cylinder movement. The recently proposed particle finite element method is employed, which combines the robustness of classical continuum mechanics formulations in terms of representing complex aspects of the material constitutive behavior, with the effectiveness of discrete element methods in simulating ultralarge deformation problems. The investigation focuses on the effect of embedment depth, cylinder roughness, granular matter macromechanical properties, and of the magnitude of the cylinder's horizontal displacement on the amplitude of the resisting forces, which are discussed in light of published experimental data. Interpretation of the results provides insight on how the material flow around the cylinder affects the developing resistance, and a mechanism is proposed to describe the development of a steady-state drag force at large horizontal movements of the cylinder.
Kouretzis GP, Ansari Y, Pineda J, Kelly R, Sheng D, 'Numerical evaluation of clay disturbance during blade penetration in the flat dilatometer test', Geotechnique Letters, 5 91-95 (2015) [C1]
This paper presents a study on the amplification of horizontal soil stresses during flat dilatometer test (DMT) blade penetration based on three-dimensional total and effective st... [more]
This paper presents a study on the amplification of horizontal soil stresses during flat dilatometer test (DMT) blade penetration based on three-dimensional total and effective stress numerical analyses, while considering stress-flow coupling and large deformations. The focus here is on saturated clays, and the effect of soil stress history on the horizontal stress index is discussed in detail. The obtained results appear to be in good agreement with published and new field data, leading to the proposal of two new expressions for estimating the overconsolidation ratio and the earth pressure coefficient at rest directly from flat dilatometer tests in estuarine clays.
Zheng C, Kouretzis GP, Sloan SW, Liu H, Ding X, 'Vertical vibration of an elastic pile embedded in poroelastic soil', Soil Dynamics and Earthquake Engineering, 77 177-181 (2015) [C1]
Â© 2015 Elsevier Ltd. We present an analytical study on the vertical vibration of an elastic pile embedded in poroelastic soil. The poroelastic soil is divided into a homogeneous ... [more]
Â© 2015 Elsevier Ltd. We present an analytical study on the vertical vibration of an elastic pile embedded in poroelastic soil. The poroelastic soil is divided into a homogeneous half-space underlying the pile base and a series of infinitesimally thin independent layers along its shaft. The dynamic interaction problem is solved by extending a method originally proposed for an embedded rigid foundation. The validity of the derived solution is verified via comparison with existing solutions. Arithmetical examples are used to demonstrate the sensitivity of the vertical pile impedance to the relative rigidity of the two soil parts.
Zheng C, Kouretzis GP, Ding X, Liu H, Poulos HG, 'Three-dimensional effects in low-strain integrity testing of piles: Analytical solution', Canadian Geotechnical Journal, 53 225-235 (2015)
Â© 2016, National Research Council of Canada. All Rights reserved. The interpretation of low-strain integrity tests of piles is commonly based on methods developed around the oned... [more]
Â© 2016, National Research Council of Canada. All Rights reserved. The interpretation of low-strain integrity tests of piles is commonly based on methods developed around the onedimensional wave propagation theory. In reality, waves resulting from the impact of a hammer on a pile head propagate in three dimensions, and the validity of the plane-front assumption is rather questionable for cases where the size of the hammer is small relative to that of the pile. This paper presents an analytical model of the dynamic response of a pile to an impact load on its head, considering propagation of waves in both vertical and radial directions. The proposed formulation applies to a pile of finite length embedded in multilayered elastic soil, and allows for considering both shape and material pile defects, by reducing locally the radius of the pile cross section or the YoungÂ¿s modulus of its material. Arithmetic examples are used to depict the effect of high-frequency interferences on the interpretation of pile integrity tests, which can only be accounted for in the threedimensional formulation of the problem, and lead to practical suggestions for the interpretation of such tests.
Kouretzis GP, KrabbenhÃ¸ft K, Sheng D, Sloan SW, 'Soil-buried pipeline interaction for vertical downwards relative offset', Canadian Geotechnical Journal, 51 1087-1094 (2014) [C1]
Kouretzis GP, Andrianopoulos KI, Sloan SW, Carter JP, 'Analysis of circular tunnels due to seismic P-wave propagation, with emphasis on unreinforced concrete liners', COMPUTERS AND GEOTECHNICS, 55 187-194 (2014) [C1]
Ansari Y, Kouretzis GP, Sheng D, 'An effective stress analysis of partially embedded offshore pipelines: Vertical penetration and axial walking', COMPUTERS AND GEOTECHNICS, 58 69-80 (2014) [C1]
Kouretzis GP, Sheng D, Wang D, 'Numerical simulation of cone penetration testing using a new critical state constitutive model for sand', Computers and Geotechnics, 56 50-60 (2014) [C1]
A new perspective on the numerical simulation of cone penetration in sand is presented, based on an enhanced critical state model implemented in an explicit-integration finite ele... [more]
A new perspective on the numerical simulation of cone penetration in sand is presented, based on an enhanced critical state model implemented in an explicit-integration finite element code. Its main advantage, compared to similar studies employing simpler soil models, is that sand compressibility can be described with a single set of model parameters, irrespective of the stress level and the sand relative density. Calibration is based on back-analysis of published centrifuge experiments, while results of the methodology are also compared against independent tests. Additional analyses are performed to investigate sand state effects on cone penetration resistance, in comparison with empirical expressions from the literature. Â© 2013 Elsevier Ltd.
Hambleton JP, Kouretzis GP, Sloan SW, 'Introduction to the CGSE Special Issue of Australian Geomechanics', Australian Geomechanics, 49 1-2 (2014) [C3]
Kouretzis GP, Sheng D, Wang D, 'Numerical simulation of CPT cone penetration in sand', Applied Mechanics and Materials, 553 416-421 (2014) [C1]
Numerical simulation of cone penetration in sand is performed by means of a computationally efficient critical state model implemented in an explicit-integration finite element co... [more]
Numerical simulation of cone penetration in sand is performed by means of a computationally efficient critical state model implemented in an explicit-integration finite element code. Its main advantage, compared to other published studies employing simpler soil models such as the Drucker-Prager, is that sand compressibility can be described with a single set of model parameters, irrespective of the stress level and the sand relative density. Calibration of the constitutive model is based on back-analysis of published centrifuge tests results, and consequently the predictions of the numerical methodology are compared against independent tests. Additional analyses are performed for proposing a new simplified formula to correlate the cone penetration resistance with the in situ sand relative density. Â© (2014) Trans Tech Publications, Switzerland.
Kouretzis G, Ansari Y, Pineda J, Sheng D, 'Experimental and numerical investigation of rate and softening effects on the undrained shear strength of Ballina clay', Australian Geomechanics Journal, 49 51-57 (2014) [C1]
Kouretzis GP, Sheng D, Sloan SW, 'Sand-pipeline-trench lateral interaction effects for shallow buried pipelines', Computers and Geotechnics, 54 53-59 (2013) [C1]
A large-deformation numerical methodology is applied to simulate the interaction effects for a pipeline installed in a trench backfilled with loosely deposited dry sand, focusing ... [more]
A large-deformation numerical methodology is applied to simulate the interaction effects for a pipeline installed in a trench backfilled with loosely deposited dry sand, focusing on shallow buried pipelines subjected to lateral displacements relative to the surrounding soil. Based on the backfill-pipeline deformation mode under shallow embedment conditions, described in previous experimental studies, analyses are performed while considering only the critical state shear strength parameters of the backfill. The numerical methodology is validated against experimental full-scale test measurements from the literature, for pipelines buried in uniform dry loose and medium sand. Parametric analyses are performed to generate approximate formulas and charts for calculating (i) the maximum force on the pipeline and (ii) the minimum trench dimensions to eliminate interaction with the surrounding natural ground. Application of the proposed approach in the prediction of independent full-scale test results for a pipeline embedded in a shallow trench demonstrates its effectiveness, and underlines the effect of trench dimensioning on the response of the pipeline. Â© 2013 Elsevier Ltd.
Kouretzis GP, Sloan SW, Carter JP, 'Effect of interface friction on tunnel liner internal forces due to seismic S- and P-wave propagation', SOIL DYNAMICS AND EARTHQUAKE ENGINEERING, 46 41-51 (2013) [C1]
Kouretzis GP, Bouckovalas GD, Gantes CJ, 'Analytical calculation of blast-induced strains to buried pipelines', INTERNATIONAL JOURNAL OF IMPACT ENGINEERING, 34 1683-1704 (2007) [C1]
Karamitros DK, Bouckovalas GD, Kouretzis GP, 'Stress analysis of buried steel pipelines at strike-slip fault crossings', SOIL DYNAMICS AND EARTHQUAKE ENGINEERING, 27 200-211 (2007) [C1]
Kouretzis GP, Bouckovalas GD, Gantes CJ, '3-D shell analysis of cylindrical underground structures under seismic shear (S) wave action', SOIL DYNAMICS AND EARTHQUAKE ENGINEERING, 26 909-921 (2006) [C1]
Bouckovalas GD, Kouretzis GP, Kalogeras IS, 'Site-specific analysis of strong motion data from the September 7, 1999 Athens, Greece earthquake', NATURAL HAZARDS, 27 105-131 (2002) [C1]
Bouckovalas GD, Kouretzis GP, 'Stiff soil amplification effects in the 7 September 1999 Athens (Greece) earthquake', SOIL DYNAMICS AND EARTHQUAKE ENGINEERING, 21 671-687 (2001) [C1]
|Show 20 more journal articles|
Review (1 outputs)
George P Kouretzis, Mark J Masia, Clive Allen, 'Structural Design Codes of Australia and New Zealand: Seismic Actions (2014) [D1]
Conference (1 outputs)
Ansari Y, Kouretzis GP, Sheng D, 'Coupled finite element analysis of partially embedded offshore pipelines during vertical penetration', Applied Mechanics and Materials (2014) [E1]
Diverse vertical embedment response is observed for partially embedded pipelines when experimentally tested under similar initial and boundary conditions. Although vertical resist... [more]
Diverse vertical embedment response is observed for partially embedded pipelines when experimentally tested under similar initial and boundary conditions. Although vertical resistance of pipelines is presented through simple analytical solutions, a number of factors contribute to complications in implementing these theories into practice. The objectives of this research is to provide a more detailed investigation on the vertical embedment for the partially-embedded pipelines (PEPs) using a coupled large deformation finite element (CLDFE) analysis with contact. A modified Cam Clay (MCC) model represents the elastoplastic response of the soil. The model of pipeline embedment investigates the effect of drainage condition on heave forming with respect to rate of penetration. Besides, effect of frictional contact on the heave development and wedging effect is investigated and design-related considerations are proposed. It is shown that depending on the rate of pipeline penetration and soil consolidation rate, the pipeline penetration response can be categorised as undrained, partially drained or fully drained. Â© (2014) Trans Tech Publications, Switzerland.
Other (1 outputs)
Hambleton JP, Kouretzis GP, Sloan SW, 'Introduction to the Â¿CGSE Special IssueÂ¿ of Australian Geomechanics', ( issue.4 pp.1-2): The Australian Geomechanics Society (2014)
Grants and Funding
|Number of grants||4|
Click on a grant title below to expand the full details for that specific grant.
20151 grants / $463,900
Funding body: ARC (Australian Research Council)
|Funding body||ARC (Australian Research Council)|
|Project Team||Doctor George Kouretzis, Professor Daichao Sheng, Associate Professor Kristian Krabbenhoft|
|Type Of Funding||Aust Competitive - Commonwealth|
20142 grants / $60,000
Research of partial embedment of pipelines and study of pipeline 3D lateral buckling analysis$40,000
Funding body: Hyundai Heavy Industries
Funding body: University of Newcastle
|Funding body||University of Newcastle|
|Project Team||Associate Professor Adrian Russell, Professor Nasser Khalili, Dr Gaofeng Zhao, Dr Arman Khoshghalb, Laureate Professor Scott Sloan, Doctor George Kouretzis, Professor Buddhima Indraratna, Dr Cholachat Rujikiatkamjorn, Professor Mark Cassidy, Professor Christophe Gaudin, Professor David Williams, Dr Alexander Scheuermann|
|Type Of Funding||Internal|
20131 grants / $5,000
New Staff Grant 2012$5,000
Funding body: University of Newcastle
|Funding body||University of Newcastle|
|Project Team||Doctor George Kouretzis|
|Scheme||New Staff Grant|
|Type Of Funding||Internal|
Number of supervisions
Total current UON EFTSL
|Commenced||Level of Study||Research Title / Program / Supervisor Type|
Experimental and Numerical Modelling of Soft Soil Testing Techniques
PhD (Civil Eng), Faculty of Engineering and Built Environment, The University of Newcastle
Modelling of Embankments on Improved Soft Soils
PhD (Civil Eng), Faculty of Engineering and Built Environment, The University of Newcastle
November 19, 2014
Dr Georgios Kouretizis, Professor Daichao Sheng and Associate Professor Kristian Krabbenhoft have been awarded more than $463,000 in ARC Discovery Project funding commencing in 2015 for their research project Unsaturated soil-structure interaction with emphasis on buried pipelines.
Dr George Kouretzis
School of Engineering
Faculty of Engineering and Built Environment
|Phone||(02) 4921 6449|
Callaghan, NSW 2308