arc centre of excellence for geotechnical science and...

ARC Centre of Excellence for

Geotechnical Science and Engineering

2011 ANNUAL REPORT

PUBLICATION DETAILS

PARTNER ORGANISATIONSENQUIRIES AND FURTHER INFORMATION

Laureate Professor Scott SloanDirectorARC Centre of Excellence for Geotechnical Science & Engineering

The University of Newcastle Callaghan, NSW 2308 Australia

T: + 61 4921 6059F: + 61 4921 6991E: [email protected]

Design:RAEONTHELAMB

Editor:Scott Sloan

Assistant Editors:Kirstin DunncliffJim Hambleton

Printing:ONA Print Graphics

http://www.newcastle.edu.au/research-centre/cgse/

TABLE OF CONTENTS

ARC Centre of Excellence for Geotechnical Science & Engineering – 2011 Annual Report

TABLE OF CONTENTS

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[06] MISSION STATEMENT

[06] RESEARCH GOALS

[07] DIRECTOR’S STATEMENT

[10] RESEARCH TEAM

[17] RHD STUDENTS

[27] MANAGEMENT COMMITTEE

[28] ADVISORY BOARD

[29] OFFICIAL CENTRE LAUNCH

[30] RESEARCH PROGRAMS

[35] VISITORS AND COLLABORATION

[40] PUBLICATIONS

[48] PLENARY, KEYNOTE & INVITED LECTURES

[49] RESEARCH SEMINARS

[52] SELECTED ACHIEVEMENTS

[55] EXTERNAL FUNDING AWARDED

[58] SELECTED RESEARCH PROJECTS

[81] ANNUAL WORKSHOP

[82] WEBSITE

[82] CONTRIBUTION TO THE NATIONAL BENEFIT

[83] CENTRE PERFORMANCE (30 JUNE 2011 – 31 DECEMBER 2011)

[86] FINANCIAL REPORT

[91] FINANCIAL STATEMENT

MISSION STATEMENT

RESEARCH GOALS


MISSION STATEMENT/RESEARCH GOALS

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Provide a national focus for geotechnical research by integrating the expertise of the key Australian geotechnical research groups into a single centre. This will ensure that new offshore and onshore geotechnologies can be developed in a coherent and unified fashion, as well as establish a critical research mass and allow cross-pollination between the strengths of the different nodes.

Optimise the design of critical infrastructure by combining fundamental work in geotechnical science, cutting edge computational modelling, state of the art physical modelling and field testing to make the engineering of Australia’s infrastructure safer and more cost effective.

Educate and train the next generation of geotechnical engineers and researchers.

Collaborate with the offshore and onshore construction industry to ensure (i) a rapid uptake of geotechnologies and design practices and (ii) sustainability of the CGSE funding, post ARC support.

The Centre will pioneer new scientific approaches to geotechnical engineering design. This will underpin Australia’s energy and transport infrastructure, resulting in increased productivity and sustainability of the nation’s major export industries.

DIRECTOR’S STATEMENT



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This is the first Annual Report for the Australian Research Council Centre of Excellence for Geotechnical Science & Engineering (CGSE), a collaborative research centre that capitalises on the combined strengths of the Priority Research Centre for Geotechnical and Materials Modelling (CGMM) at The University of Newcastle, the Centre for Offshore Foundation Systems (COFS) at The University of Western Australia, and the Centre for Geotechnics and Railway Engineering (GRE) at The University of Wollongong. The Centre also includes two world-renowned partner investigators in Professor Harry Poulos from Coffey Geotechnics and Professor Vaughan Griffiths from the Colorado School of Mines. Industry sponsors of the Centre’s research are Coffey Geotechnics, Douglas Partners, and Advanced Geomechanics. The total Centre funding is approximately $23M over a seven year period.

The Centre formally commenced operation at the end of June 2011 and much of our initial energy has thus been focused on recruiting key

personnel including Post-doctoral Researchers, a Business Manager, a Centre Administrator, as well as numerous research students. A comprehensive website has been established (http://www.newcastle.edu.au/research-centre/cgse/) which will continue to be expanded in the coming months. Two Centre workshops, attended by over 60 staff and research students, have served to launch collaborative research between the nodes in a major way. These workshops have been reinforced by staff exchanges and over a dozen key collaborative projects are now in full swing.

With the support of the Roads and Traffic Authority of NSW and its Partner Organisations, the Centre will be establishing Australia’s first national soft soil testing site at Ballina NSW in 2012. A development application and environmental impact report for this site, totalling more than 160 pages, have been lodged with Ballina Shire Council for approval. Work on this national testing facility will commence as soon as approval is obtained, and it will serve as a national focal point for engaging the geotechnical industry in the science and



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GEOTECHNICAL SCIENCE

PHYSICAL MO

DELLING

TECHNIQ

UES

Centrifuge: hybrid ‘whole of life’ m

odels O

-tube: fluid-structure-soil interaction. N

ovel site investigation technologies

Geomaterial Science Behaviour of soft

soils: structure, anisotropy, creep

Mechanisms of damage & rate dependence

Response through lifelong cyclic loading

Ultra low stress soil mechanics, liquefaction, softening

Micromechanics of cyclic deformation

Multiphysics Modelling Multi-phase models

for solid-to-fluid transitions

Multiscale modelling, upscaling from discrete grains to a continuum

Thermo-hydro-mechanical models

Electro-osmotic consolidation

Granular hydrodynamics

Constitutive models for interfaces

Moving Boundaries Large

deformation FEA Soil-structure-

fluid interaction with moving interfaces

Deep penetration, foundation uplift and anchor pull-out

Dynamic effective stress contact mechanics

Simulation of intelligent penetrometry

GeoRisk Stochastic limit

analysis & FEA Stochastic

wave-structure-soil interaction

Stochastic site characterisation & reliability-based interpretation

Stochastic modelling of fissured media

Geohazards: quantifying the risk of failure

NEW TOOLS

Robust computational methods; analysis

techniques & software packages

ENGINEERING APPLICATIONS Ground improvement for facilities on soft and problematic soils; Deepwater gas

frontiers: pipelines, risers, foundations, floating systems; Foundations for renewable energy; Hazard assessment (geo-, metocean): landslides, structures,

tunnels; Efficient infrastructure for heavy haul roads & rail.

NEW TOOLS Direct design: in situ model tests, intelligent site

characterisation

engineering of construction on soft soil. Key features of the national site at Ballina will be full-scale testing of embankments, advanced in situ and laboratory testing to characterise the soil, reduced-scale centrifuge modelling, and state-of-the-art numerical modelling to compare with observed behaviour. Once the embankments are built, an international prediction symposium will be organised, with some of the world’s leading geotechnical research groups and engineering firms being invited to participate.

In line with the Centre’s focus on the development of advanced computational methods, a rack-mounted farm of high performance computer servers has been established at The University of Newcastle. This system is configured with sophisticated tools for code development, as well as a range of geotechnical software, and can be accessed remotely by all researchers in the Centre.

The Centre aims to provide a national focus for geotechnical research by integrating the complementary expertise of three key Australian geotechnical research groups into a single unit. This will ensure that new offshore and onshore geotechnologies can be developed in a coherent and unified fashion, as well as establishing a critical research mass and cross-pollination between the strengths of the nodes. The Centre has four geotechnical science themes, each of which will be linked to advanced computational modelling, state-of-the-art physical modelling, laboratory testing, full-scale testing, and engineering applications. These fundamental themes are described in the diagram below.

The first meeting of the Management Committee was held in February 2011, prior to the official commencement date of the Centre, with key personnel from all nodes coming together in Newcastle. Key topics discussed included the budget, recruitment of new staff, the initial focus themes for research,

Above: Centre for Geotechnical Science and Engineering – fundamental science.



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and implementation of collaboration between the nodes. This was followed up with regular meetings of the Management Committee via phone hook-ups.

Lachlan Bates, formerly the laboratory manager for the Priority Research Centre for Geotechnical and Materials Modelling, was appointed to the position of Business Manager at Newcastle. His much awaited replacement, Michele Spadari, commenced duty in December 2011 which has allowed Lachlan to focus solely upon the Centres’ activities, particularly in relation to industry liaison, financial management, laboratory testing and experimental research work.

The Newcastle node also welcomed Kirstin Dunncliff as Centre Administrator. Kirstin has taken on numerous administrative tasks relating to the effective operation of the Centre including financial management, development and maintenance of the website, organisation of the research seminar series, preparation of report and meeting documents, collection of data on outputs, and the arrangement of travel and accommodation for Centre staff and visitors.

Centre researchers have had a very successful year on the funding front, obtaining a large ARC Infrastructure Equipment and Facilities grant from the ARC for a National Centrifuge Facility (a collaboration between UWA, Newcastle, Wollongong, Monash, Adelaide and Queensland) as well as a number of ARC Discovery and Linkage grants and industry projects which will be discussed in further detail later in this report.

The achievements of individuals within the Centre are numerous and will be detailed elsewhere, but particular highlights include Scott Sloan’s invitation to deliver the 51st Rankine Lecture in London, Mark Randolph’s election as a Fellow of the Royal Society, Mark Randolph’s award of an ARC Discovery Outstanding Researcher Award (DORA), Buddhima Indraratna’s election to a Fellowship of the Academy of Technological Sciences and Engineering, and David White’s award as the Early Career Scientist of the Year for Western Australia. In addition, two of our talented young staff, Dr Shanyong Wang and Dr Cholachat Rujikiatkamjorn, were successful in obtaining 3-year ARC CoE Early Career Researcher Support Award(s) on the theme of Ground improvement methods for soft and problematic soils.

Over the course of the coming months, we look forward to welcoming new research staff and students to the Centre who will help us pioneer new scientific approaches to the geotechnical design of Australia’s energy and transport infrastructure.

Scott Sloan FAA FTSE FIEAustLaureate Professor Scott SloanARC Centre of Excellence for Geotechnical Science & Engineering

RESEARCH TEAM


RESEARCH TEAM

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The CGSE combines two of the world’s leading geotechnical research groups, the Centre for Geotechnical and Materials Modelling at Newcastle led by Laureate Professor Scott Sloan, and the Centre for Offshore Foundation Systems at The University of Western Australia led by Professor Mark Cassidy. It also includes the highly influential Geotechnics and Railway Engineering Centre at The University of Wollongong, led by Professor Buddhima Indraratna, which has a worldwide reputation for its work on transport infrastructure.

The list of participating researchers includes three Rankine Lecturers (Poulos, Randolph, Sloan), a Terzaghi Lecturer (Poulos), an ARC Laureate Fellow (Sloan), three ARC Future Fellows (Cassidy, White, Krabbenhoft), an ARC Federation Fellow (Randolph), four Fellows of the Australian Academy of Science (Poulos, Randolph, Sloan, Carter), six Fellows of the Australian Academy of Technological Sciences and Engineering (Poulos, Randolph, Sloan, Carter, Cassidy, Indraratna), a Fellow of the Royal Society and the Royal Academy of Engineering (Randolph), and five E H Davis Memorial Lecturers (Poulos, Randolph, Sloan, Carter, Indraratna).

These researchers, together with the other Chief Investigators, have been recipients of the highest awards possible in the field of geotechnical engineering. All the participating groups have extensive experience in managing large research projects and working closely with government and industry infrastructure firms.


RESEARCH TEAM

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Laureate ProfessorSCOTT SLOANFAA FTSEThe University of Newcastle

ProfessorJOHN CARTER AMAM FAA FTSEThe University of Newcastle

ProfessorBUDDHIMA INDRARATNAFTSEThe University of Wollongong

Associate ProfessorANDREI LYAMINThe University of Newcastle

Winthrop ProfessorMARK RANDOLPHFAA FBE FREng FTSEThe University of Western Australia

ProfessorDAVID WHITEThe University of Western Australia

Winthrop ProfessorMARK CASSIDYFTSEThe University of Western Australia

ProfessorCHRISTOPHE GAUDINThe University of Western Australia

Associate ProfessorKRISTIAN KRABBENHOFTThe University of Newcastle

Associate ProfessorRICHARD MERIFIELDThe University of Newcastle

ProfessorDAICHAO SHENGThe University of Newcastle

DIRECTOR DEPUTY DIRECTOR

CHIEF INVESTIGATORS


RESEARCH TEAM

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ProfessorHARRY POULOSAM, FAA, FTSE, Hon FIEAust, Dist MASCECoffey Geotechnics

DoctorANDREW ABBOThe University of Newcastle

Assistant ProfessorNATHALIE BOUKPETIThe University of Western Australia

DoctorOLIVIER BUZZIThe University of Newcastle

Assistant ProfessorSCOTT DRAPERThe University of Western Australia

ProfessorSTEPHEN FITYUSThe University of Newcastle

ProfessorD VAUGHAN GRIFFITHSColorado School of Mines

Associate ProfessorBRITTA BIENENThe University of Western Australia

Assistant ProfessorNOEL BOYLANThe University of Western Australia

ProfessorJ ANTONIO H CARRAROThe University of Western Australia

DoctorXIAOWEI FENGThe University of Western Australia

DoctorXUEYU GENGThe University of Wollongong

PARTNER INVESTIGATORS

ASSOCIATES

DoctorANNA GIACOMINIThe University of Newcastle

Associate ProfessorWEI-DONG GUOThe University of Wollongong

Assistant ProfessorJAMES HENGESHThe University of Western Australia

DoctorJINSONG HUANGThe University of Newcastle

DoctorMEHRDAD KIMIAEIThe University of Western Australia

DoctorXU LIThe University of Western Australia

ProfessorSUSAN GOURVENECThe University of Western Australia

DoctorJAMES HAMBLETONThe University of Newcastle

DoctorMUHAMMAD SHAZZAD HOSSAINThe University of Western Australia

DoctorMD REZAUL KARIMThe University of Newcastle

DoctorGEORGE KOURETZISThe University of Newcastle

DoctorXIANFENG LIUThe University of Newcastle


RESEARCH TEAM

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RESEARCH TEAM

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DoctorMAJIDREZA NAZEMThe University of Newcastle

DoctorCHOLACHAT RUJIKIATKAMJORNThe University of Wollongong

DoctorSAMUEL STANIERThe University of Western Australia

DoctorKLAUS THOENIThe University of Newcastle

DoctorBRETT TURNERThe University of Newcastle

DoctorCRISTINA VULPEThe University of Western Australia

DoctorSANJAY SHRAWAN NIMBALKARThe University of Wollongong

DoctorWOJCIECH SOLOWSKIThe University of Newcastle

ProfessorBORIS TARASOVThe University of Western Australia

Associate ProfessorCONLETH O’LOUGHLINThe University of Western Australia

DoctorYINGHUI TIANThe University of Western Australia

DoctorCHET VIGNESThe University of Newcastle


RESEARCH TEAM

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Assistant ProfessorDONG WANGThe University of Western Australia

DoctorSHANYONG WANGThe University of Newcastle

DoctorHONGXIA ZHUThe University of Western Australia

DoctorCHAO YANGThe University of Newcastle

MrLACHLAN BATESThe University of Newcastle

MsKIRSTIN DUNNCLIFFThe University of Newcastle

MrsMICHELLE GRANTThe University of Western Australia

MsLISA MELVINThe University of Western Australia

MrsROMA HAMLETThe University of Wollongong

MrsMONICA MACKMANThe University of Western Australia

BUSINESS MANAGERS

CENTRE ADMINISTRATORS

ACCOUNTS OFFICER ADMINISTRATIVE OFFICER


RESEARCH TEAM

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MrJOSHUA KAUTTOThe University of Newcastle

MrALAN GRANTThe University of Wollongong

MrPETER TURNERThe University of Wollongong

MrMICHELE SPADARIThe University of Newcastle

IT SUPPORT

TECHNICAL SUPPORT


RHD STUDENTS

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RHD STUDENTS

During 2011 the Centre actively recruited Research Higher Degree (RHD) students, both nationally and internationally. At The University of Newcastle, eight (8) offers were made and accepted with students to commence in 2012. There is one (1) domestic candidate and seven (7) international candidates who are currently going through the visa application process. Students have been aligned with one of the four major research themes and, where appropriate, will be supervised jointly across the nodes.

At The University of Western Australia, since the beginning of the CGSE, three (3) new international PhD students have commenced. Three (3) offers were made at the end of 2011 and all are international candidates who are currently going through the visa application process. Another four (4) international students will be transferring from the Institute of Technology Sligo (Ireland) during 2012.


RHD STUDENTS

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MS HANA ABU ZAHER

PhD (Civil, Surveying & Environmental Engineering) The University of Newcastle

Georemediation - the removal of fluoride from spent potliner (SPL) contaminated groundwater using calcite and zeoliteSupervisors: Scott Sloan, Brett Turner

MR YOUSEF ANSARI


Evaluation of hydraulic conductivity characteristics of clays via piezocone dissipation testsSupervisors: Daichao Sheng, Scott Sloan, Richard Merifield, Majidreza Nazem

MR LACHLAN BATES

M Eng (Civil, Surveying & Environmental Engineering) The University of Newcastle

Interpretation of in situ test resultsSupervisors: Stephen Fityus, Emoke Imra

MR GLEN BURTON


Mechanics of partially saturated soilsSupervisors: Daichao Sheng, Scott Sloan, David Airey (Sydney)

MR MASON CRUMPTON


Computational methods in limit analysisSupervisors: Andrew Abbo, Scott Sloan, Andrei Lyamin, Jim Hambleton


RHD STUDENTS

19

MR RYAN DE CARTERET


The relationship between salinity and road pavementsSupervisors: Stephen Fityus, Olivier Buzzi

MR SANTIRAM CHATTERJEE

PhD (Civil & Resource Engineering) The University of Western Australia

Modelling of pipeline seabed interactionsSupervisors: Dave White, Mark Randolph

MR NING (STEVEN) CHENG


Dynamic pushover analysis of jack-up platforms using plasticity models for spudcan-soil interactionSupervisors: Mark Cassidy, Mehrdad Kimiaei

MR INDRANIL GUHA


Structural analysis of submarine pipelines under submarine slide and thermal loadingSupervisors: Dave White, Mark Randolph

MR PAN HU


Numerical analysis on spudcan foundations with large penetration into multilayered soilsSupervisors: Mark Cassidy, Dong Wang, Samuel Stanier

MR MOHAMMAD OMID KARDANI


Iterative methods for solving large sparse linear systems arising from computational plasticity problemsSupervisors: Andrei Lyamin, Kristian Krabbenhoft

MS MINA KARDANI


Large deformation analysis in geomechanics using adaptive finite element methodsSupervisors: Daichao Sheng, Scott Sloan

Submitted in 2011, awarded in 2012

MR KOUROSH KIANFAR

PhD (Civil Engineering) The University of Wollongong

Implication of pre-fabricated vertical drains and vacuum preloading on viscoplastic behaviour of soft soilsSupervisors: Buddhima Indraratna, Cholochat Rujikiatkmjorn

MR OMID KOHAN


Improving spudcan extraction from deep embedment in soft soilsSupervisors: Mark Cassidy, Britta Bienen, Christophe Gaudin

MS VICKIE KONG


Jack-up reinstallation near existing spudcan footprintSupervisors: Mark Cassidy, Christophe Gaudin

Submitted February 2012


RHD STUDENTS

20

MR XIAOJUN LI


The uplift capacity of mudmat foundationsSupervisors: Mark Cassidy, Christophe Gaudin, Yinghui Tian

MR CHENGCAI LUO


On-bottom stability of submarine pipelines on mobile seabedSupervisors: Liang Cheng, Dave White, Mark Randolph

MR JIAJIE MA


Numerical modelling of submarine landslides and their impact on offshore infrastructure using the material point method (MPM)Supervisors: Mark Randolph, Dong Wang, Adam Wittek, Karol Miller

MRS DIVYA SALLIYIL KODAKKATTU MANA


Numerical and experimental investigation of offshore skirted foundations subjected to general loadingSupervisors: Susan Gourvenec, Shazzad Hossain, Mark Randolph

MR MOHAMMAD SAEED MASOOMI


Dynamic soil-structure-water interactionSupervisors: Andrew Abbo, Majidreza Nazem, John Carter


RHD STUDENTS

21

MR MOHAMMAD HESAM MOAVENIAN

PhD (Civil, Surveying & Environmental Engineering)

The University of Newcastle

Dynamic soil structure interactionSupervisors: Majidreza Nazem, John Carter, Andrew Abbo

MR JALAL MIRZADEHNIASAR


Probabilistic models for dynamic collapse of jacket offshore platforms under extreme wavesSupervisors: Mehrdad Kimiaei, Mark Cassidy

MR HENNING MOHR

PhD (Civil & Resource Engineering)

The University of Western Australia

Pipeline and seabed behavior under storm waves; numerical and physical modellingSupervisors: Dave White, Liang Cheng, Mark Randolph

MR MATHARAGE DARSHANA ANURADHA PERERA

PhD (Civil Engineering)

The University of Wollongong

Evaluation and reduction of time dependent (creep) settlement of reclamation soils improved using vertical drains and vacuum preloadingSupervisors : Buddhima Indraratna, Cholachat Rujikiatkamjorn

MR NATHAN PODLICH


The formulation of parallel algorithms for large-scale limit and shakedown analysisSupervisors: Andrei Lyamin, Scott Sloan, Andrew Abbo


RHD STUDENTS

22

MR HAMED MAHMOODZADEH POORNAKI

PhD (Civil Engineering) The University of Western Australia

Intepretation of partially drained penetrometer tests with application to the design of spudcan foundationsSupervisors: Mark Randolph, Noel Boylan, Mark Cassidy

MS LUCILE QUEAU


Fatigue design of steel catenary risers in the touchdown zone, considering nonlinear riser-soil interactionSupervisors: Mehrdad Kimiaei, Mark Randolph

MR HASSAN SABETAMAL


Finite element algorithms for dynamic analysis of geotechnical problemsSupervisors: Majidreza Nazem, Richard Merifield, Scott Sloan

MR LUDGER RAUSCH


Combined load capacity of shallow foundations for offshore energy productionSupervisors: Britta Bienen, Mark Cassidy

MR AMIN RISMANCHIAN


Three dimensional modelling of pipeline buckling on soft claySupervisors: Dave White, Mark Randolph


RHD STUDENTS

23

MR FAUZAN SAHDI


Modelling of submarine slides and their impact on pipelinesSupervisors: Dave White, Noel Boylan, Christophe Gaudin, Mark Randolph

MR FIRMAN RAYBAT SIAHAAN


Geonsynthetically-encapsulated granular column in soft soil improvementSupervisors: Buddhima Indraratna, Cholachat Rujikiatkamjorn

MR HAMID TOHIDIFA


Effect of high speed train frequencies on the degradation of rail ballast upon cyclic densificationSupervisors: Buddhima Indraratna, Song-Ping Zhu

MR STEFANUS SAFINUS


Estimation of spudcan penetration resistance in layered soils directly from field penetrometer data and quantification of punch-through riskSupervisors: Shazzad Hossain, Mark Randolph, Mark Cassidy

MS SOMAYE SADEGHIAN


To be advisedSupervisor: Mark Randolph


RHD STUDENTS

24

MR BEAU WHITNEY


Neotechnocs of Western Australia: paleoseismology of the Mt. Narryer fault zoneSupervisors: James Hengesh, Dr Karl-Heinz Wyrwoll, Dave White

MR DANIEL WILSON


Stability of underground openingsSupervisors: Scott Sloan, Andrew Abbo

MS YUE YAN


Novel methods for characterising pipe-soil interaction forces in situ in deep waterSupervisors: Dave White, Mark Randolph

MR CHANDRASIRI KUMARA WANAYALAGE


Load deformation behaviour of sediment infilled rock joints subjected to internal water flow

Supervisors: Buddhima Indraratna, Song-Ping Zhu, Jan Nemcik

MR ZACH WESTGATE


Deep water pipeline embedment in soft clay due to dynamic lay processesSupervisors: Dave White, Mark Randolph


RHD STUDENTS

25

MR BASSEM YOUSSEF


Use of probability models in the integrated analysis of offshore pipelinesSupervisors: Mark Cassidy, Yinghui TianSubmitted December 2011

MR XUE ZHANG


DFEM and its applications to large deformation problems in geomechanicsSupervisors: Daichao Sheng, Kristian Krabbenhoft

MR YOUHU ZHANG


A force resultant footing model for spudcan foundations of offshore jack-up drilling rigs in soft claySupervisors: Britta Bienen, Mark Cassidy


RHD STUDENTS

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MANAGEMENT COMMITTEE

The Management Committee is chaired by the Director, and its membership consists of the four research program leaders (Geomaterials Science, Multi-physics Modelling, Moving Boundary Problems, and Georisk) as well as the Newcastle node Business Manager. The Management Committee meets regularly via phone hook-up and at least twice a year face-to-face to allow each node to report on progress. The composition and responsibilities of the Management Committee are shown below:

Scott Sloan Chair, Director of Centre, Newcastle node leader

Mark Cassidy Deputy Director of Centre, UWA node leader, co-leader Georisk program

Buddhima Indraratna Wollongong node leader, co-leader Geomaterial Science program

Lachlan Bates Newcastle node Business Manager

John Carter Co-leader Geomaterial Science program

Kristian Krabbenhoft Co-leader Multiphysics Modelling program

Andrei Lyamin Co-leader Georisk program

Mark Randolph Co-leader Moving Boundary Problems program

Daichao Sheng Co-leader Moving Boundary Problems program

David White Co-leader Multiphysics Modelling program

TERMS OF REFERENCE

The Management Committee is responsible for the day-to-day running of the Centre, with its primary responsibilities being:

1. To formulate long term research strategies.

2. To review the progress of scientific objectives and adjust the scope of programs as needed.

3. To recruit research staff and research students.

4. To maintain budgetary targets.


MANAGEMENT COMMITTEE

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ADVISORY BOARD

CHAIR

Professor Scott Sloan FAA FTSE Director CGSE, The University of Newcastle

TERMS OF REFERENCE

The Board will meet annually to discuss progress, budgets, future directions, strategic planning, technology transfer and additional funding opportunities from government bodies and industry. Important functions of the Advisory Board include:

1. Identification of key research problems in the geotechnical aspects of energy and transport infrastructure.

2. Advice on strategies for collaborating with industry-based partners on research, such as the joint preparation of large-scale Linkage Projects to the Australian Research Council.

3. Advice on the need for workshops and conferences that can be run under the umbrella of the Centre.

4. Advice on short courses for the further education of engineers.

5. Advice on suitable Key Performance Indicators for the Centre.

6. The use of Key Performance Indicators to drive behaviour.

MEMBERS

Professor Ted Brown AC FREng FTSEGolders Associates

Professor John Carter AM FAA FTSEPro-Vice Chancellor, Faculty of Engineering and Built Environment, The University of Newcastle

Winthrop Professor Mark Cassidy FTSEDeputy Director CGSE, The University of Western Australia

Professor Buddhima Indraratna FTSEThe University of Wollongong

Professor Harry Poulos AM, FAA, FTSE, Hon FIEAust, Dist MASCESenior Principal, Coffey Geotechnics

Dr Marc SendersPrincipal Geotechnical Engineer, Woodside Energy

Dr Phil WatsonDirector, Advanced Geomechanics


ADVISORY BOARD

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Mr Will WrightPrincipal, Douglas Partners

Dr Suzanne Lacasse MNAE, FCAE, FRSC, FNAE, FNAS, FEIC, FFAS, FRSN, FASCETechnical Director, Norwegian Geotechnical Institute, Oslo

EX-OFFICIO MEMBERS

Professor Mike Calford DVC Research, The University of Newcastle

Professor Robyn Owens DVC Research, The University of Western Australia

Professor Judy Raper FTSE DVC Research, The University of Wollongong

OFFICIAL CENTRE LAUNCH

The Newcastle node has received an internal grant of $500,000 to substantially refurbish offices where the Centre staff are situated. This work is scheduled to start in June and will cause some disruption as staff are required to relocate to temporary accommodation for a period of approximately three months. Once these renovations have been completed, an official launch of the Centre will be announced. It is anticipated that this will occur towards the end of 2012.


OFFICIAL CENTRE LAUNCH

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RESEARCH PROGRAMS

As described previously, research in the CGSE is focused broadly on the geotechnical aspects of energy and transport infrastructure and is composed of four main themes: Geomaterials Science, Multiphysics Modelling, Moving Boundary Problems, and Georisk. Each of these themes will be investigated comprehensively and capitalise on the world-leading research strengths of the Centre for Geotechnical and Materials Modelling at Newcastle (advanced computational methods and in situ testing), the Centre for Offshore Foundation Systems at The University of Western Australia (physical modelling and laboratory testing), and the Centre for Geotechnics and Railway Engineering at the The University of Wollongong (transportation geotechnics and ground improvement strategies for soft soils). Each of the four programs is now briefly described.


RESEARCH PROGRAMS

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GEOMATERIAL SCIENCE

PROGRAM LEADERS

Professor Buddhima Indraratna and Professor John Carter

OVERVIEWThe complexity in the behaviour of geomaterials is largely attributable to their granular nature and the presence of internal structure and multiple phases (solid, liquid and gas), as well as the marked influence of stress level and history. Key innovations, involving all the nodes, will include the formulation of new models for highly compressible soft soils, as found on seabeds and in estuarine deposits, as well as novel ground improvement methods such as vacuum consolidation. Challenging aspects to be pursued will include the unresolved problems of creep and thixotropy in geomaterials, the role of damage at the macro and micro-scales under static and cyclic loading, the fundamental mechanisms that govern rate-dependent behaviour, the mechanical response at ultra-low effective stresses (crossing the solid-fluid boundary and linking, for example, with scour), and the micromechanical origins of cyclic instability. These mechanisms govern the life-cycle response of heavy haul road pavements and cyclically-loaded foundations.

RHD STUDENTS

Mr Yousef Ansari

Mr Glen Burton

Mr Kourush Kianfa

Mr Matharage Darshana Anuradha Perera

Mr Firman Raybat Siahaan

Mr Hamid Tohidifar

Mr Chandrasiri Kumara Wanayalage

Mr Beau Whitney

RESEARCH STAFF

Associate Professor Britta Bienen

Assistant Professor Nathalie Boukpeti

Assistant Professor Noel Boylan

Associate Professor Wei-Dong Guo

Dr James Hambleton

Assistant Professor James Hengesh

Dr Richard Kelly

Associate Professor Kristian Krabbenhoft

Associate Professor Richard Merifield

Dr Majidreza Nazem

Dr Sanjay Nimbalkar

Winthrop Professor Mark Randolph

Dr Cholachat Rujikiatkamjorn

Professor Daichao Sheng

Laureate Professor Scott Sloan

Professor Boris Tarasov

Dr Geng Xueyu

Dr Shanyong Wang

Professor David White

1PROGRAM


RESEARCH PROGRAMS – PROGRAM 1: GEOMATERIAL SCIENCE

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2 MULTIPHYSICS MODELLING

PROGRAM LEADERS

Professor David White and Associate Professor Kristian Krabbenhoft

OVERVIEWEngineering geotechnical design problems span material behaviour beyond the domain of conventional soil mechanics. This behaviour is often governed by multiphysical processes of conventional soil mechanics that operate at different length and time scales. Examples include submarine slides, where geomaterials at high water content may transfer into non-Newtonian fluids, and the influence of gas which can alter the response radically. Similarly, the frictional strength of soil-structure interfaces depends crucially on the contact micromechanics, varying by an order of magnitude with loading rate and accumulated displacement. Key innovations in this Program will address the multi-faceted behaviour of geomaterials, developing thermodynamically-sound multiphase models and efficient computational algorithms for solving complex problems including soft sea bed sediments and highly compressible estuarine clays, coupled thermo-hydro-mechanical problems including soft seabed sediments and highly compressible estuarine clays, coupled thermo-hydro-mechanical phenomena, and dissociation of gas hydrates. Sophisticated physical modelling, with visualisation of the deformation modes, will underpin the development of advanced computation algorithms for capturing the multi-phase material response. This synergy, which harnesses the strengths of the various geotechnical groups, is a major feature of the CGSE and used across all the research programs.

RHD STUDENTS

Mr Xiaojun Li

Mr Chengcai Luo

Mrs Divya Salliyil Kodakkattu Mana

Mr Mohammad Saeed Masoomi

Mr Henning Mohr

Mr Xue Zhang

RESEARCH STAFF


Winthrop Professor Mark Cassidy

Assistant Professor Scott Draper

Professor Christophe Gaudin

Professor Susan Gourvenec

Assistant Professor James Hengesh

Dr Jinsong Huang


Professor Daichao Sheng

Dr Wojciech Solowski

Dr Samuel Stanier

Professor Boris Tarasov

Associate Professor Mario Vicente Da Silva

Assistant Professor Dong Wang

PROGRAM


RESEARCH PROGRAMS – PROGRAM 2: MULTIPHYSICS MODELLING

32

PROGRAM LEADERS

Professor Daichao Sheng and Winthrop Professor Mark Randolph

OVERVIEWCurrent best-practice in geotechnical design is focused on stationary systems and constant material properties, aiming to attain negligible movement under working loads. However, many new infrastructure applications require an entirely new design paradigm which allows the geostructure to move large distances during its design life. Important examples include submarine pipelines on soft sediments, dynamic anchor installations in seabeds, installation of displacement piles, penetrometers used to measure geotechnical properties of soils, and foundations on soft clays. Key innovations in this Program include new analysis techniques that account for large deformations, soft-fluid-structure interaction, episodes of cyclic loading (and intervening recovery) and complicated interface behaviour. All three nodes in the CGSE have strong backgrounds in modelling complex boundary value problems, and will contribute to the development of novel techniques to simulate these phenomena. Moreover, the predictions from the advanced computational models will be compared against real behaviour observed in state-of-the-art physical modelling and field testing.

RHD STUDENTS

Mr Santiram Chatterjee

Mr Mason Crumpton

Mr Indranil Guha

Mr Pan Hu

Mr Mohamman Omid Kardani

Mr Jiajie Ma

Mr Nathan Podlich

Mr Hamed Mahmoodzadeh Poornaki

Mr Amin Rismanchian

Mr Fauzan Sahdi

Mr Zach Westgate

Mr Daniel Wilson

Ms Yue Yan

RESEARCH STAFF

Dr Andrew Abbo


Winthrop Professor Mark Cassidy

Professor Christophe Gaudin

Professor Susan Gourvenec

Dr James Hambleton

Dr Xu Li

Dr Majid Nazem


Dr Samuel Stanier

Dr Yinghui Tian

Assistant Professor Dong Wang

Professor David White

MOVING BOUNDARY PROBLEMS 3PROGRAM


RESEARCH PROGRAMS – PROGRAM 3: MOVING BOUNDARY PROBLEMS

33

GEORISK

PROGRAM LEADERS

Winthrop Professor Mark Cassidy and Associate Professor Andrei Lyamin

OVERVIEWIn response to industry and community demands, the modelling and management of geotechnical risk has become a major issue in the design of all forms of physical infrastructure. Indeed, the natural variability in geological deposits, coupled with the existing uncertainty in loading conditions and limited on-site data, make this a very challenging aspect for government authorities and engineering practice. There is a compelling case to extend traditional deterministic design procedures to a stochastic framework. Key innovations in this Program include the development of new stochastic limit and shakedown analysis techniques to predict the load capacity of geostructures under static and cyclic loads, new methods for the stochastic modelling of wave-structure-soil interaction with application to offshore production rigs, and the risk-based prediction of slope stability and landslides and their effect on onshore and seabed infrastructure (such as pipelines). The Program will draw on the numerical modelling strengths of the Newcastle node, the centrifuge and constitutive modelling expertise of the UWA node, the extensive cyclic loading knowledge of the Wollongong node, and the probabilistic modelling expertise of PI Griffiths at Colorado to provide rational and complete treatment of this challenging topic.

RHD STUDENTS

Mr Ning (Steven) Cheng

Mr Omid Kohan

Ms Vickie Kong

Mr Jalal Mirzadehniasar

Ms Lucile Queau

Mr Ludger Rausch

Mr Stefanus Safinus

Mr Bassem Youssef

Mr Youhu Zhang

RESEARCH STAFF

Dr Andrew Abbo


Professor John Carter

Assistant Professor Scott Draper

Professor Vaughan Griffiths

Dr Jinsong Huang

Dr Mehrdad Kimiaei

Dr Xu Li



Dr Yinghui Tian

4PROGRAM


RESEARCH PROGRAMS – PROGRAM 4: GEORISK

34

VISITORS AND COLLABORATION


VISITORS & COLLABORATION

35

Mr Alexandre Depouhon from the University of Minnesota and Université de Liège, US/Belgium visited the CGSE and gave a talk on multi-scale modelling of materials and structures and discussed future research in drilling mechanics.

Dr Konstantinos Georgiadis from the Aristotle University of Thessaloniki, Greece visited the CGSE from September 2011 – March 2012 and collaborated with Scott Sloan and Andrei Lyamin on semi-analytical and numerical limit analysis of deep foundations.

Dr Mario Vicente da Silva from the University Nova of Lisbon, Portugal visited the Centre from September 2011 – March 2012 and collaborated with Kristian Krabbenhoft and Andrei Lyamin on various research projects.

Professor Lanru Jing from the Royal Institute of Technology, Sweden visited the CGSE during July 2011 to collaborate with Daichao Sheng on the hydro-mechanical behaviour of bentonite used in nuclear waste deposits.

Professor Jinchun Chai from the Saga University, Japan visited the CGSE during March 2011 to collaborate with John Carter and Daichao Sheng on a range of research topics including the simulation and interpretation of piezocone penetration tests.

Professor Gernot Beer from the Graz University of Technology, Austria visited the CGSE during July-August 2011 to collaborate with Scott Sloan on advanced numerical analysis of tunnelling using BEM/FEM. Professor Beer also provided a post-graduate course on nonlinear finite element analysis.

Professor Kentaro Yamamoto from Kagoshima University, Japan visited the CGSE during August and September 2011 to collaborate with Scott Sloan, Andrei Lyamin and Andrew Abbo on geotechnical stability analysis. Professor Yamamoto’s stay was supported by grants from the Japanese and Australian Academies of Science.

Professor Yves Leroy from the Laboratoire de Geologie, CNRS, France visited the CGSE in July 2011 to collaborate with Kristian Krabbenhoft on research on limit analysis in structural geology.

Professor Wei Wu from the Universitat fur Bodenkultur, Vienna visited the CGSE in June 2011 and presented his research on ‘Hypoplastic constitutive model: stability and regularization’.

Associate Professor Itai Einav from the University of Sydney visited the CGSE in June 2011 to collaborate on modelling of flow and segregation of granular materials. James Hambleton also spent 4 days in Sydney in October 2011 to consolidate their research.

Professor F Collin from the Liege University, Belgium visited the CGSE in July 2011 to collaborate with Olivier Buzzi on the THM coupling in underground fires.

Dr James Hambleton visited Professor Vaughan Voller at the University of Minnesota, USA in July 2011 for research collaboration on the use of control volume finite elements in solid mechanics, especially computational limit analysis.

Professor D Vaughan Griffiths is visiting the CGSE from September 2011 – April 2012. Professor Griffiths is Professor of Civil Engineering at the Colorado School of Mines and is a Partner Investigator in the CGSE. Professor Griffiths is collaborating with several members in the Centre including Scott Sloan, Jinsong Huang, and Andrei Lyamin.

Mr Ivo Raissakas, Masters Student, Graz University of Technology is visiting the CGSE from October until June 2012 to work on his master thesis. The work is about a comparison between Plaxis (strength reduction) and Lower and Upper bounds.



36

Dr Jonathan Black from the University of Sheffield, UK visited the CGSE during November 2011 for a few days to discuss his research with the CGSE researchers.

Ms Adriane Boscardin from the University of Massachusetts Amherst, USA spent 4 weeks working in the CGSE laboratories during October – November 2011 as part of the USA’s NSF Collaborative Exchange Scheme on developing international protocols for offshore geohazards.

Ms Fiona Boumard from the University of Toulon Var, France completed her internship at the CGSE during June – August 2011 working with Scott Draper on the project wave energy resource assessment for a real site.

Professor Antonio Carraro from Colorado State University, USA visited the CGSE during August 2011 for a week, sharing his experiences with the geotechnical research lab he manages at Colorado State University. Antonio was offered a Professor position and started January 2012.

Ms Jade Chung from the University of Maine, USA visited the CGSE during June – July 2011 and September – October 2011 to conduct centrifuge tests with Christophe Gaudin, Mark Cassidy and Melissa Landon-Maynard on alternative foundations for floating wind turbines.

Mr Nick Coleman from the University of Tasmania visited the CGSE during November 2011 – February 2012. Nick was awarded a CGSE vacation scholarship and worked with Mark Cassidy and Vickie Kong on the installation of spudcan foundations next to existing footprints. Nick conducted a series of tests at various offsets from a footprint in sand.

Mr Danqing (David) Dong from the University of Adelaide visited the CGSE during November 2011 – February 2012. David was awarded a CGSE vacation scholarship and worked with Shazzad Hossain on the experimental investigation of perforation drilling for reinstallation of spudcan foundations close to existing footprints.

Dr Xiaowei Feng from Tianjin University, China visited the CGSE during May 2010 – May 2011 working with Susan Gourvenec, Mark Randolph and Christophe Gaudin on finite element analysis and centrifuge modelling of rectangular skirted foundations under general 6 degree of freedom loading, with the aim of developing a simplified design methodology for offshore manifolds and mudmats. Xiaowei started at the CGSE as a Lecturer (LRET Assistant Professor for Deepwater Engineering) in August 2011.

Dr Dengfeng Fu from Tianjin University, China is visiting the CGSE during August 2011 – July 2012 and working with Britta Bienen, Christophe Gaudin and Mark Cassidy on numerical analyses of hybrid skirted foundations. He is helping prepare for a series of PIV centrifuge tests scheduled for early 2012.

Mr Chao Han from China is visiting the CGSE during November 2011 – April 2012. Chao’s visit started when he finished his Bachelor of Engineering degree from UWA. He is working with Dong Wang on research into the prediction of keying of suction embedded plate



37

anchor using analytical and numerical approaches.

Dr Sascha Henke from Hamburg University of Technology, Germany visited the CGSE during March 2011 and November – January 2012. Sascha provided the impetus to revive our pile driving hammer for the beam centrifuge. Together with Britta Bienen, Sascha performed an extensive series of tests to investigate plugging during the installation of various pile profiles into sand.

Dr Esve Jacobsz from the University of Pretoria, South Africa visited the CGSE during January 2011. Esve was here for 3 days working with Dave White on the centrifuge.

Mr Cody Jones from the University of Massachusetts Amherst, USA visited the CGSE during September – October 2011. As part of the USA’s National Science Foundation Collaborative Exchange Scheme on developing international protocols for offshore geohazards Cody spent 3 weeks in UWA laboratories.

Mr Youngho Kim from Korea is visiting the CGSE during December 2011 – December 2012 and is working with Shazzad Hossain on FE modelling of pull-out capacity of torpedo anchors.

Mr Kai Xiang Koh from the University of Queensland visited the CGSE during November 2011 – February 2012. Kai was awarded a CGSE vacation scholarship and is working with Shazzad Hossain on 3D FE modelling of torpedo anchor pull-out.

Dr Melissa Landon-Maynard from the University of Maine, USA visited the CGSE during June 2011. A regular visitor to the CGSE, Melissa returned in 2011 with her

student Jade Chung to conduct centrifuge tests on alternative foundations for floating wind turbines.

Dr Anjui Li from Deakin University visited the CGSE during December 2011. A UWA PhD graduate, Anjui returned for a short visit working with Mark Cassidy on research into probabilistic assessment of rock slope stability.

Mr Xiaojun Li from the Chinese Academy of Sciences, China visited the CGSE during August 2010 – September 2011 and worked with Christophe Gaudin and Mark Cassidy on the uplift of deep water manifold foundations. He was awarded a postgraduate scholarship and started his PhD with the CGSE in October 2011.

Dr Mohammad Mahdi Memarpour from Iran University of Technology, Iran visited the CGSE during May – June 2011. Mohammad continued his research collaboration with Mehrdad Kimiaei from his previous visit to COFS in 2010, and spent a couple of weeks writing papers with Mehrdad.

Dr David Masin from Charles University, Czech Republic visited the CGSE during January 2011. David spent a week at the CGSE working with Britta Bienen on hypoplasticity. He also conducted a short PhD course on fine-grained soil behaviour, fundamentals of hypoplasticity, modelling of fine- and course-grained soils using hypoplasticity, application of hypoplasticity in solving boundary value problems and demonstration of its use in the most common finite element software packages (PLAXIS, ABAQUS).

Mr Joseph Newhouse from the UK visited the CGSE during September 2011 – March 2012. After finishing his Degree, Joseph came to the CGSE to do research



38

Associate Professor Yajun Jiang from the School of Civil Engineering, Southwest Jiaotong University, Chengdu, Sichuan Province, China visited the CGSE as an Endeavour research fellow and collaborated with Buddhima Indraratna during April-September 2011 on the finite element simulation of high speed railways.

Associate Professor Sujit Kumar Dash from the Department of Civil Engineering, Indian Institute of Technology Guwahati, India visited the CGSE to work on the behaviour of ballast under impact loads during January-June 2011 under an Endeavour Fellowship award.

Dr K S Vipin, Post Doctoral Fellow from the Department of Civil Engineering, Indian Institute of Science (IISc) visited the CGSE on an Endeavour Fellowship and collaborated with Buddhima Indraratna during February-September 2011 on the cyclic behaviour of soil subjected to radial consolidation.

work with Britta Bienen on predicting the foundation performance of offshore jack-up drilling rigs in intermediate soils.

Professor Alexander (Sasha) Puzrin from ETH Zurich, Switzerland visited the CGSE during January – February 2011. Sasha came to the CGSE on a Gledden Visiting Senior Fellowship and collaborated with Mark Randolph on advancing the fundamental understanding of the mechanisms of submarine landslides and their effect on offshore infrastructure. During his visit he also presented a public lecture on “The leaning tower of St Moritz: geotechnical aspects of construction on a creeping landslide”.

Ms Christina Rudolph from Hamburg University of Technology, Germany visited the CGSE during October – December 2011 for 7 weeks, working with Britta Bienen on cyclic lateral loading of piles. These centrifuge tests were performed with the application to offshore wind installations in mind.

Mr Kouhei Sawada from the Tokyo Institute of Technology, Japan visited the CGSE during March – July 2011. Kouhei collaborated with Mark Randolph and Britta Bienen on research into pile raft design methods.

Mr Søren Peder Hyldal Sørensen from Aalborg Universty, Denmark visited the CGSE during November 2010 – March 2011 working with Mark Randolph on different approaches to model the lateral response on monopoles for offshore wind farms, comparing finite element and beam column approaches and assessed how best to take account of scouring and the consequential reduction of stress in the soil at shallow depths around the piles.

Dr Marco Uzielli from Georisk Engineering S.r.l., Italy visited the CGSE during July – August 2011 working with Mark Cassidy, Yinghui Tian and Shazzad Hossain on establishing a portfolio of Georisk research in the CGSE. We hope that Marco will be a regular visitor with shorter visits anticipated for 2012. These will concentrate on probabilistic techniques for assessing the punch-through potential of jack-up platforms and the variability of shallow foundation combined loading envelops.

Ms Qiuchen Wei from Tianjin University, China is visiting the CGSE during November 2011 – October 2012. Qiuchen is working with Mark Cassidy, Dong Wang, Yinghui Tian and Christophe Gaudin on the Australia-China Natural Gas Partnership grant entitled “geotechnical solutions for engineering deep water gas fields”. Quichen is investigating the change in yield surface size and shape with SEPLA geometry using the finite element method.

Mr Feng (David) Yuan from Zhejiang University, China is visiting the CGSE during September 2011 – September 2012. David is completing his PhD at Zhejiang University.

Mr Ehssan Zargar from Iran visited the CGSE during May 2011 – February 2012. Ehssan is working with Mehrdad Kimiaei and Mark Randolph on dynamic analysis of steel catenary risers using soil-fluid-structure interaction models. Ehssan was recently awarded a PhD scholarship and will be shortly starting at the CGSE as a PhD student.

Ms Fuyu Zhao visited the CGSE during November 2011 – February 2012. Fuyu was awarded a CGSE vacation scholar and is working with Scott Draper on experiments related to scour from backfilled pipeline trenches.

Mr Jingbin Zheng from China is visiting the CGSE during September 2011 – August 2012. Jingbin is working with Shazzad Hossain on research on the estimation of spudcan penetration resistance in stratified soils directly from field penetrometer data and quantification of punch-through risk. Jingbin was recently awarded a postgraduate scholarship and will be starting his PhD with us soon.



39

PUBLICATIONS

BOOKS

Chai J, Carter JP (2011). Deformation Analysis in Soft Ground Improvement. Springer, Dordrecht.

Indraratna B, Salim, W, Rujikiakamjorn C (2011). Advanced Rail Geotechnology – Ballasted Track. Taylor & Francis, London.

Randolph M, Gourevenec S (2011). Offshore Geotechnical Engineering. Taylor & Francis, London.

BOOK CHAPTERS

Clukey EC and Randolph MF (2011). The application of centrifuge model testing to deepwater geotechnical problems. Chapter 6 in Deepwater Foundations and Pipeline Geomechanics. McCarron WO (Ed). J Ross Publishing, Fort Lauderdale.


PUBLICATIONS – BOOKS/BOOK CHAPTERS

40

JOURNAL PAPERS

[A]

Abbo AJ, Lyamin AV, Sloan SW, Hambleton JP (2011). A C2 continuous approximation to the Mohr–Coulomb yield surface. International Journal of Solids and Structures, 48(21), 3001-3010.

Abdelrazaq A, Badelow F, Sung HK, Poulos HG (2011) Foundation design of the 151 story Incheon Tower in a reclamation area. Geot. Eng., Jnl. Of the SEAGS & AGSSEA, 42(2), 85-93.

Acosta-Martinez HE, Gourvenec SM, Randolph MF (2011). Centrifuge study of capacity of a skirted foundation under eccentric transient and sustained uplift. Géotechnique, doi:10.1680/geot.9.P.027.

Airey DW, Carter JP, Liu MD (2011). Sydney Soil Model. II: Experimental validation. International Journal of Geomechanics, 11(3), 225-238

Anbazhagan P, Indraratna B, Su L, Rujikiatkamjorn C (2011). Model track studies on fouled ballast using ground penetration radar and multichannel analysis of surface wave. Journal of Applied Geophysics, 74, 175–184.

Ansari Y, Merifield RS, Yamamoto H, Sheng D (2011). Numerical analysis of soilbags under compression and cyclic shear. Computers and Geotechnics, 38(5), 504-514.

[B]

Bienen B, Jan Dührkop J, Grabe J, Randolph MF, White DJ (2011). The response of piles with wings to monotonic and cyclic lateral loading in sand. ASCE Journal of Geotechnical and Geoenvironmental Engineering, doi:10.1061/(ASCE)GT.1943-5606.0000592.

Boukpeti N, White DJ, Randolph MF, Low HE (2011). Strength of fine-grained soils at the solid-fluid transition. Géotechnique, (in press).

Boukpeti N, White DJ, Randolph MF (2011). Analytical modelling of the steady flow of a submarine slide and consequent loading on a pipeline. Géotechnique, 62(2), 137-146.

Buzzi O, Giacomini A, Fityus S (2011). Towards a dimensionless description of soil swelling behaviour. Géotechnique, 61(3), 271-277.

Buzzi O, Giacomini A, Spadari M (2011). Laboratory investigation on high values of restitution coefficients. Rock Mechanics and Rock Engineering. doi:10.1007/s00603-011-0183-0.

[C]

Cassidy MJ (2011). Assessing the three-dimensional response of jack-up platforms in directional seas. KSCE Journal of Civil Engineering, Special Issue on Energy Geotechnology,15(4), 623-634.

Cassidy MJ (2011). Experimental observations of the penetration of spudcan footings in silt. Géotechnique, (in press).

Chai JC , Agung PMA, Hino T, Igaya Y, Carter JP (2011). Estimating hydraulic conductivity from piezocone soundings. Géotechnique, 61(8), 699–708.

[D]

Doherty J, Fahey M (2011). Three dimensional finite element analysis of the direct simple shear test. Computers and Geotechnics, 38, 917–924.

Duenser C, Thoeni K, Riederer K, Lindner B, Beer G (2011). New developments of the boundary element method for underground constructions. International Journal of Geomechanics, (in press).


PUBLICATIONS – JOURNAL PAPERS [A–D]

41

[F]

Fahey M, Helinksi M, Fourie A (2011). Development of specimen curing procedures that account for the influence of effective stress during curing on the strength of cemented mine backfill. Journal of Geotechnical & Geoenvironmental Engineering, 137(2), 171-182.

Fenton GA, Griffiths DV, Ojomo OO (2011). Consequence factors in the ultimate limit state design of shallow foundations. Canadian Geotechnical Journal, 48(2), 265-279.

Fityus SG, Wells PA, Huang W (2011). Water content measurement in expansive soils using the neutron probe, Geotechnical Testing Journal, 34, 1-10.

Fredlund DG, Sheng D, Zhao J (2011). Estimation of soil suction from the soil water characteristic curve. Canadian Geotechnical Journal, 48, 186-198.

[G]

Gaudin C, Bienen B, Cassidy MJ (2011). Investigation of the potential of bottom water jetting to ease spudcan extraction in soft clay. Géotechnique. 61(12), 1043-1054.

Gaudin C, Cassidy MJ, Bienen B, Hossain MS (2011). Recent contributions of geotechnical centrifuge modelling to the understanding of jack-up spudcan behaviour. Ocean Engineering, 38(7), 900-914.

Geng XY, Indraratna B, Rujikiatkamjorn C (2011). Analytical solutions for a single vertical drain with vacuum and time-dependent surcharge preloading in membrane and membraneless systems. International Journal of Geomechanics, (in press).

Geng XY, Indraratna B, Rujikiatkamjorn C (2011). The effectiveness of partially penetrating vertical drains under a combined surcharge and vacuum preloading, Canadian Geotechnical Journal , 48(6), 970-983.

Gourvenec S, Barnett S (2011). Undrained failure envelope for skirted foundations under general loading. Géotechnique, 61(3), 263-270.

Gourvenec S, Mana DSK (2011). Undrained vertical bearing capacity factors for shallow foundations. Géotechnique Letters, 1(4), 101-108.

Govoni L, Gourvenec S, Gottardi G (2011). A centrifuge study on the effect of embedment on the drained response of shallow foundations under combined loading. Géotechnique, 61(12), 1055-1068.

Griffiths DV, Huang J, deWolfe GF (2011). Numerical and analytical observations on long and infinite slopes. International Journal for Numerical and Analytical Methods in Geomechanics, 35(5), 569-585.

Griffiths DV, Huang J, Fenton GA (2011). Probabilistic infinite slope analysis. Computers and Geotechnics, 38(4), 577-584.

Guruprasad B, Indraratna B, Nghiem LD, Regmi G (2011). A neural network approach to predict the performance of recycled concrete used in permeable reactive barriers for the treatment of acidic groundwater. Quarterly Journal of Engineering Geology and Hydrogeology, 44 (2), 199–209.

[H]

Helinksi M, Fahey M, Fourie A (2011). Behaviour of cemented paste backfill in two mine stopes - measurements and modelling. Journal of Geotechnical & Geoenvironmental Engineering, 137 (2), 171-182.


PUBLICATIONS – JOURNAL PAPERS [F–H]

42

Hossain MS, Cassidy MJ, Baker R, Randolph MF (2011). Optimisation of perforation drilling for mitigating punch-through in multi-layered clays. Canadian Geotechnical Journal, 48(11), 1658-1673.

Hossain MS, Lehane BM, Hu Y, Gao Y (2011). Soil flow mechanisms around and between stiffeners of caissons during installation in clay. Canadian Geotechnical Journal, (in press).

Hossain MS, Randolph MF, Saunier YN (2011). Spudcan deep penetration in multi-layered fine-grained soils. International Journal of Physical Modelling in Geotechnics, 11(3), 100-115.

Hossain MS, Randolph MF (2011). Reply to Discussion by E.T.R. Dean on “Deep-penetrating spudcan foundations on layered clays: centrifuge tests”(original paper Géotechnique, 60(3),157–170). Géotechnique, 61(1), 85–87.

Houlsby GT, Cassidy MJ (2011). A simplified mechanically based model for predicting partially drained behaviour of penetrometers and shallow foundations. Géotechnique Letters, 1(3), 65-69.

Huang M, Liu Y, Sheng D (2011). Simulation of yielding and stress-stain behavior of shanghai soft clay, Computers and Geotechnics, 38, 341-353.

Huang J, Griffiths DV, Wong SW (2011). Characterizing natural fracture permeability from mud loss data. SPE Journal, 16(1), 111-114.

Huang J, Griffiths DV, Wong SW (2011). Initiation pressure, location and orientation of hydraulic fracture. International Journal of Rock Mechanics and Mining Sciences, doi:10.1016/j.ijrmms.2011.11.014.

Huang J, Griffiths DV, Wong SW (2011). In situ stress determination from inversion of hydraulic fracturing data. International Journal of Rock Mechanics and Mining Sciences, 48(3), 476-481.

Huang J, Griffiths DV (2011). Observations on FORM in a simple geomechanics example. Structural Safety, 33(1), 115-119.

Huang M, Liu Y, Sheng D (2011). Simulation of yielding and stress-strain behavior of Shanghai soft clay. Computers and Geotechnics, 38, 341-353.

[I]

Indraratna B, Hussaini SKK, Vinod JS (2011). On the shear behavior of ballast-geosynthetic interfaces. ASTM Geotechnical Testing Journal, (in press).

Indraratna B, Rujikiatkamjorn C, Kelly R, Buys H (2011). Soft soil foundation improved by vacuum and surcharge loading. Ground Improvement, (in press).

Indraratna B, Rujikiatkamjorn C, Balasubramaniam AS, McIntosh G (2011). Soft ground improvement via vertical drains and vacuum assisted preloading. Geotextiles and Geomembranes, (in press).


PUBLICATIONS – JOURNAL PAPERS [H–I]

43

Indraratna B, Thakur PK, Vinod JS, Salim W (2011). A semi-empirical cyclic densification model for ballast incorporating particle breakage. International Journal of Geomechanics, (in press).

Indraratna B, Rujikiatkamjorn C, Ameratunga J, Boyle P (2011). Performance and prediction of vacuum combined surcharge consolidation at Port of Brisbane. Journal of Geotechnical & Geoenvironmental Engineering, 137(11), 1009-1018.

Indraratna B, Nguyen VT, Rujikiatkamjorn C (2011). Assessing the potential of internal erosion and suffusion of granular soils. Journal of Geotechnical & Geoenvironmental Engineering, 137(5), 550-554.

Indraratna B, Su L, Rujikiatkamjorn C (2011). A new parameter for classification and evaluation of railway ballast fouling. Canadian Geotechnical Journal, 48 (2), 322-326.

Indraratna B, Ngo NT, Rujikiatkamjorn C (2011). Behavior of geogrid-reinforced ballastunder various levels of fouling. Geotextiles and Geomembranes, 29, 311-322.

Indraratna B, Nguyen VT, Rujikiatkamjorn C (2011). Assessing the potential of internal erosion and suffusion of granular soils. Journal of Geotechnical & Geoenvironmental Engineering, 137(5), 550-554.

Indraratna B, Su L, Rujikiatkamjorn C (2011). A new parameter for classification and evaluation of railway ballast fouling. Canadian Geotechnical Journal, 48, 322-326.

Indraratna B, Ngo NT, Rujikiatkamjorn C (2011). Behavior of geogrid-reinforced ballast under various levels of fouling. Geotextiles and Geomembranes, 29 (3), 311-322.

[J]

Jiang AN, Wang SY, Tang SL (2011). Feedback analysis of tunnel construction using a hybrid arithmetic based on Support Vector Machine and Particle Swarm Optimisation. Automation in Construction, 20, 482-489.

[K]

Krost K, Gourvenec SM, White DJ (2011). Consolidation around partially-embedded submarine pipelines. Géotechnique, 61(2), 167-173.

[L]

Lee J, Randolph MF (2011). Penetrometer based assessment of spudcan penetration resistance. Journal of Geotechnical and Geoenvironmental Engineering, 137(6), 587-596.


PUBLICATIONS – JOURNAL PAPERS [I–L]

44

Leong Y-K, Teo J, Teh EJ, Smith J, Widjaja J, Lee JX, Fourie A, Fahey M, Chen R (2011). Controlling attractive interparticle forces via small anionic and cationic additives in kaolin clay slurries. Chemical Engineering Research & Design, doi:10.1016/j.cherd.2011.09.002.

Li AJ, Merifield RS, Lyamin AV (2011). Effect of rock mass disturbance on the stability of rock slopes using the Hoek-Brown failure criterion. Computers and Geotechnics, 38(4), 546-558.

Li LC, Tang CA, Wang SY (2011). Numerical investigation on fracture infilling and spacing in layered rocks subjected to hydro-mechanical loading. Rock Mechanics and Rock Engineering, (in press).

Liu M, Indraratna B (2011). General strength criterion for geometerials including anisotropic effect, International Journal of Geomechanics, 11(3), 251-262.

Liu MD, Carter JP, Airey DW (2011). Sydney Soil Model. I: Theoretical formulation. International Journal of Geomechanics, 11(3), 211-224.

Liu XL, Wang EZ, Wang SY, Wang SJ (2011). Bonded-particle modeling of fluid-driven fractures in granular materials. Philosophical Transactions A, (in press).

Low HE, Landon MM, Randolph MF, DeGroot DJ (2011). Geotechnical characterisation and engineering properties of Burswood clay. Géotechnique, 61(7), 575-591.

Low HE, Randolph MF, Lunne T, Andersen KH, Sjursen MA (2011). Effect of soil characteristics on relative values of piezocone, T-bar and ball penetration resistances. Géotechnique, 61(8), 651-664.

Lu MM, Xie KH, Wang SY (2011). Consolidation of vertical drain with depth-varying stress induced by multi-stage loading. Computers and Geotechnics, 38, 1096-1101.

Lu MM, Xie KH, Wang SY, Li CX (2011). Analytical solution for the consolidation of a composite foundation reinforced by an impervious column with an arbitrary stress increment. International Journal of Geomechanics, (in press).

Lunne T, Andersen KH, Low HE, Sjursen M, Li X, Randolph MF (2011). Guidelines for offshore in situ testing and interpretation in deep water soft soils, Canadian Geotechnical Journal, 48(6), 543-556.

[M]

Mana DSK, Gourvenec SM, Randolph MF, Hossain MS (2011). Failure mechanisms of skirted foundations uplift & compression. International Journal of Physical Modelling in Geotechnics, (in press).

Merifield RS (2011). The ultimate uplift capacity of multi-plate helical type anchors in undrained clay. Journal of Geotechnical and Geoenvironmental Engineering, 137(7), 704-716.

Merifield RS, Nguyen VQ (2011). Undrained bearing capacity of footings near slopes. Australian Geomechanics Journal, 46(1), 77-94.

Menzies WT, Fenton GA, Lake CB , Griffiths DV (2011). A method to assess risk reduction when utilizing GCLs with compacted soil liners. Canadian Geotechnical Journal, 48(1), 146-161.

[N]

Nimbalkar S, Indraratna B, Dash SK, Christie D (2011). Improved performance of railway ballast under impact loads using shock mats. Journal of Geotechnical & Geoenvironmental Engineering, (in press).

[O]

Osman AS, Randolph MF (2011). An analytical solution for the consolidation around a laterally loaded pile. International Journal of Geomechanics, (in press).


PUBLICATIONS – JOURNAL PAPERS [L–O]

45

[P]

Pantelidis L, Griffiths DV (2011). Stability assessment of slopes using different factoring strategies. Journal of Geotechnical Geoenvironmental Engineering, doi:10.1061/(ASCE) GT.1943-5606.0000678.

Poulos HG, Small JC, Chow H (2011). Piled raft foundations for tall buildings. Geotechnical Engineering, Journal of the SEAGS & AGSSEA, 42(2), 78-84.

[R]

Randolph MF, Gaudin C, Gourvenec S, White DJ, Boylan N, Cassidy MJ (2011). Recent advances in offshore geotechnics for deepwater oil and gas developments. Ocean Engineering, 38(7), 818-834.

Regmi G, Indraratna B, Nghiem LD, Banasiak L (2011). Evaluating waste concrete for the treatment of acid sulphate soil groundwater from coastal floodplains. Desalination and Water Treatment, 32(1-3), 126–132.

Regmi G, Indraratna B, Nghiem LD, Golab A, Guruprasad B (2011). Treatment of acidic groundwater in acid sulfate soil terrain using recycled concrete: column experiments. Journal of Environmental Engineering, 137(6), 433-443.

Russell A, Buzzi O (2011). A fractal basis for soil-water characteristics curves with hydraulic hysteresis. Géotechnique, (in press).

[S]

Shao W, Bouzerdoum A, Phung S L, Su L, Indraratna B, Rujikiatkamjorn C (2011). Automatic classification of ground penetrating radar signals for railway ballast assessment. IEEE Transactions on Geoscience & Remote Sensing, 49, 3961-3972.

Shiau JS, Merifield RS, Lyamin AV, Sloan SW (2011). Undrained stability of footings on slopes. International Journal of Geomechanics, 11(5), 381-390.

Sheng D (2011). Review of fundamental principles in modelling unsaturated soil behaviour. Computers and Geotechnics, 38, 757-776.

Sheng D, Augarde CE, Abbo AJ (2011). A fast algorithm for finding the first intersection with a non-convex yield surface. Computers and Geotechnics, 38, 465-471.

Sheng D, Zhou AN (2011). Coupling hydraulic with mechanical models for unsaturated soils. Canadian Geotechnical Journal, 48, 826-840.

Sheng D, Zhou AN, Fredlund DG (2011). Shear strength criteria for unsaturated soils. Geotechnical and Geological Engineering, 29, 145-159.

Solowski WT, Sloan SW (2011). Equivalent stress approach in modelling unsaturated soils. International Journal for Numerical and Analytical Methods is Geomechanics, doi:10.1002/nag.1077.

Spadari M, Giacomini A, Buzzi O, Hambleton J (2011). Prediction of the bullet effect for rockfall barriers: a scaling approach. Rock Mechanics and Rock Engineering, doi:10.1007/s00603-011-0203-0.

Spadari M, Giacomini A, Buzzi O, Fityus S, Giani GP (2011). In situ rock fall testing in New South Wales, Australia. International Journal of Rock Mechanics and Mining Science, doi:10.1016/j.ijrmms.2011.11.013.

Suchoweska A, Merifield RS, Carter JP (2011). Prediction of underground cavity roof collapse using the Hoek-Brown failure criterion. Computers and Geotechnics, (in press).

[T]

Taiebat HA, Carter JP (2011). A failure surface for circular footings on cohesive soils - Discussion. Géotechnique, 61(7), 621–622.

Tarasov B, Randolph MF (2011). Superbrittleness of rocks and earthquake activity. International Journal of Rock Mechanics and Mining Science, 48(6), 888-898.

Tian Y, Cassidy MJ (2011). A pipe-soil interaction model incorporating large lateral displacements in calcareous sand. Journal of Geotechnical and Geoenvironmental Engineering, 137(3), 279-287.


PUBLICATIONS – JOURNAL PAPERS [P–T]

46

Tian Y, Cassidy MJ (2011). Incorporating uplift in the analysis of shallowly embedded pipelines. Structural Engineering and Mechanics, 40(1), 29-48.

Tian Y, Cassidy MJ, Youssef BS (2011). Consideration for on-bottom stability of unburied pipelines using a dynamic fluid-structure-soil simulation finite element program. International Journal of Offshore and Polar Engineering, 21(3), 1-8.

[V]

Vlahos G, Cassidy MJ, Martin CM (2011). Numerical simulation of pushover tests on a model jack-up platform on clay. Géotechnique, 61(11), 947-960.

[W]

Wang D, Hu Y, Randolph MF (2011). Keying of rectangular plate anchors in normally consolidated clays. Journal of Geotechnical and Geoenvironmental Engineering, 137(12), 1244-1253.

Wang SY, Chan D, Lam KC, Au SKA (2011). Laboratory study of static and dynamic compaction grouting in triaxial condition. Geomechanics and Geoengineering: An International Journal, 6(1), 9-19.

Wang SY, Sloan SW, Huang ML (2011). Numerical Study of Failure Mechanism of Serial and Parallel Rock Pillars. Rock Mechanics and Rock Engineering, 44(2), 179-198.

Wang SY, Sloan SW, Liu HY, Tang CA (2011). Numerical simulation of the rock fragmentation process induced by two drill bits subjected to static and dynamic (impact) loading. Rock Mechanics and Rock Engineering, 44(3), 317-332.

White DJ, Dingle HRC (2011). The mechanism of steady ‘friction’ between seabed pipelines and clay soils. Géotechnique, 61(12), 1035-1041.

Wilson DW, Abbo AJ, Sloan SW, Lyamin AV (2011). Undrained stability of a circular tunnel where the shear strength increases linearly with depth. Canadian Geotechnical Journal, 48(9), 1328-1342.

[Y]

Yan Y, White DJ, Randolph MF (2011). Penetration resistance and stiffness factors in uniform clay for hemispherical and toroidal penetrometers. International Journal of Geomechanics, 11(4), 263-275.

Yamamoto K, Lyamin AV, Wilson DW, Sloan SW, Abbo AJ (2011). Stability of a single tunnel in cohesive-frictional soil subjected to surcharge loading. Canadian Geotechnical Journal, 48(12), 1841-1854.

Yamamoto K, Lyamin AV, Wilson DW, Sloan SW, Abbo AJ (2011). Stability of a circular tunnel in cohesive-frictional soil subjected to surcharge loading. Computers and Geotechnics, 38(4), 504-514.

Yan Y, White DJ, Randolph MF (2011). Penetration resistance and stiffness factors in uniform clay for hemispherical and toroidal penetrometers. International Journal of Geomechanics, 11(4), 263-275.

Yang SQ, Yang DS, Jing HW, Li YH, Wang SY (2011). An experimental study of the fracture coalescence behaviour of brittle sandstone samples containing three fissures. Rock Mechanics and Rock Engineering, (in press).

Yang SQ, Jing HW, Wang SY, Pei JL (2011). Experimental study on the strength, deformability, failure behaviour and spatial acoustic emission distribution of red sandstone under triaxial compression. Rock Mechanics and Rock Engineering, (in press).

[Z]

Zhang C, White DJ, Randolph MF (2011). Centrifuge modelling of the cyclic lateral response of a rigid pile in soft clay. Journal of Geotechnical and Geoenvironmental Engineering, 137(7), 717-729.

Zhang Y, Bienen B, Cassidy MJ, Gourvenec S (2011). The undrained bearing capacity of a spudcan foundation under combined loading in soft clay. Marine Structures, 24(4), 459-477.

Zhang Y, Bienen B, Cassidy MJ, Gourvenec S (2011). Undrained bearing capacity of deeply buried flat circular foundations under general loading. Journal of Geotechnical and Geoenvironmental Engineering, doi:10.1061/(ASCE)GT.1943-5606.0000606.

Zhou H, Randolph MF (2011). Effect of shaft on resistance of a ball penetrometer. Géotechnique, 61(11), 973-981.

Zhu H, Randolph MF (2011). Numerical analysis of a cylinder moving through rate-dependent soils. Ocean Engineering, 38(7), 943-953.


PUBLICATIONS – JOURNAL PAPERS [T–Z]

47

PLENARY, KEYNOTE & INVITED LECTURES

Britta Bienen was invited to give a Guest Lecture at The Lloyds Register Educational Trust Collegium on carbon capture and sequestration in the ocean in Southampton.

Mark Cassidy presented a Keynote Lecture on the “Development and application of models for the stability analysis of Australia’s offshore pipelines” at the 2011 Symposium on Coastal and Marine Geotechnics: Foundations for Trade. This was the 15th Annual Symposium organised by the Sydney Chapter of the Australian Geomechanics Society and was attended by over 140 industry practitioners and academics.

Anna Giacomini delivered an Invited Paper on “In situ experiments of rockfall in an open pit coal mine” at Slope Stability 2011: International Symposium on Rock Slope Stability in Open Pit Mining and Civil Engineering, Vancouver, Canada.

Buddhima Indraratna delivered a Keynote Lecture on “Stabilisation of ballast and subgrade with geosynthetic grids and drains for rail infrastructure” at the International Conference on Advances in Geotechnical Engineering, Perth Australia.

Buddhima Indraratna delivered a Keynote Lecture on “Physical and chemical ground improvement for sustainable transportation infrastructure under cyclic loads” at the 3rd International Conference on Geotechnical Engineering for Disaster Mitigation and Rehabilitation, Semarang, Indonesia.

Buddhima Indraratna delivered a Keynote Lecture on “Implications of ballast breakage on ballasted railway track based on numerical modelling” at the 13th International Conference of the International Association for Computer Methods and Advances in Geomechanics, Melbourne Australia.

Daichao Sheng delivered a Keynote Lecture on “Constitutive modelling of unsaturated soils”, at the 5th International Conference on Unsaturated Soils, Barcelona, Spain.

Scott Sloan delivered the 51st Rankine Lecture on “Geotechnical stability analysis” at Imperial College, London, in March 2011.

Scott Sloan delivered a Plenary Lecture on “Accelerated convergence of Newton-Raphson method using a least squares approximation to the consistent tangent matrix” at the 13th IACMAG Conference in Melbourne.

Scott Sloan delivered the Victor Milligan Distinguished Lecture on “Geotechnical stability analysis” at the Geo Engineering Research Centre, Queen’s University, Canada.

Wojciech Solowski delivered an Invited Paper on “Explicit stress integration with reduced drift for the Barcelona Basic Model of Unsaturated Soils” at the 5th International Conference on Unsaturated Soils, Barcelona.

Shanyong Wang delivered an Invited Paper on “Numerical simulation of end restraint effects on triaxial strength of soil’’ at the International Symposium on Geomechanics and Geotechnics: From Micro To Macro, Shanghai, China.

David White delivered an Invited Lecture at the annual Offshore Technology Conference in Houston on “The Western Australian LNG story – A personal snapshot.”

Chao Yang delivered an Invited Paper on “Constitutive model of unsaturated structured soils under cyclic loading” at the 5th International Conference on Unsaturated Soils, Barcelona, Spain.


PLENARY, KEYNOTE & INVITED LECTURES

48

RESEARCH SEMINARS

[Fri 4 March] UWA Dr Scott Draper – UWA

Marine renewable energy

[Fri 18 March] UWA Dr Sascha Henke – Hamburg University of Technology, Germany Plugging of open-ended pile profiles

[Mon 11 April] Wollongong A/ Prof Antti Nurmikolu – Director of Railway Track Research Tampere University of Technology, Finland

Finnish railways and railway track research at Tampere University of Technology

[Fri 15 April] UWAAssistant Professor James Hengesh – UWA A tectonic influence on seafloor stability along Australia’s North West Shelf

[Fri 13 May] Wollongong Prof G L Sivakumar Babu – Indian Institute of Science, Bangalore Sustainability issues in pavement engineering

UWA Vickie Kong – PhD Candidate, UWA Jack-up reinstallation near existing footprint

Youhu Zhang – PhD student, UWA Development of a VHM loading apparatus at UWA drum centrifuge

[Fri 20 May] UWA Ludger Rausch – University of Applied Sciences, Darmstadt, Germany Numerical study of the combined load capacity of a hybrid foundation

Amin Rismanchian – PhD Candidate, UWA The resistance of soil berms during lateral buckling of pipelines on soft clay: an

interpretation of centrifuge modelling data

[Fri 27 May] UWA Lucile Queau – PhD Candidate, UWA Fatigue analysis of steel catenary risers using nonlinear riser-soil interaction model

[Wed 15 June] Wollongong Dr Nam Huynh Dr Long Nghiem – CME, UoW The learning curve of early career researchers: from the Shine Dome of the Australian Academy of Science to practice


RESEARCH SEMINARS

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[Fri 17 June] Newcastle Alexandre Depouhon – University of Minnesota, USA & Université de Liège, Belgium Mean-field homogenization for multi-scale modeling of materials and structures

[Tue 13 July] Newcastle Dr Lanru Jing – Royal Institute of Technology (KTH), Stockholm, Sweden DECOVALEX: An international collaborative research project on radioactive waste disposal

[Fri 16 July] Newcastle Prof Gernot Beer – Graz University of Technology, Austria Technology innovation in underground construction

[Fri 5 August] UWA Dr Marco Uzielli – Georisk Engineering, Italy Serviceability limit state CPT-based design of shallow foundations on sand

[Tue 9 August] Newcastle Nathan Podlich – PhD Candidate, UoN The formulation of parallel algorithms for large-scale limit analysis

Mason Crumpton – PhD Candidate, UoN Methods in computational limit analysis

[Fri 19 August] Newcastle Hassan Sabetamal – PhD Candidate, UoN Finite element algorithms for dynamic analysis of geotechnical problems

[Thu 25 August] Newcastle Xue Zhang – PhD Candidate, UoN Particle finite element method and its application to large deformation problems in geomechanics

[Fri 2 September] Newcastle Dr James Hambleton – UoN Modelling the evolutionary problem of a rigid object interacting with a plastically deforming surface

[Fri 9 September] UWA Chengcai Luo – PhD Candidate, UWA Submarine pipeline stability on mobile seabed-Large O-Tube

[Thu 15 September] Wollongong Udeshini Pathirage – PhD Candidate, UoW Modelling of clogging in the permeable reactive barrier (PRB) in acid sulphate soil terrain

[Fri 16 September] Newcastle Dr Jinsong Huang – UoN Reliability analysis of slopes

ARC Centre of Excellence for Geotechnical Science & Engineering - 2011 Annual Report

RESEARCH SEMINARS

50

[Fri 23 September] UWA Zack Westgate – PhD Candidate, UWA Field observations of as-laid pipeline embedment in carbonate soils

[Fri 30 September] Newcastle Dr Chao Yang – UoN Mechanical response of structured soils subjected to cyclic loading

[Fri 21 October] UWA Dr Yinghui Tian – UWA On-bottom stability analysis for shallowly embedded long offshore pipelines

[Fri 4 November] Newcastle Dr Klaus Thoeni – UoN Non-linear problems using BEM with applications in tunnelling

[Wed 9 November] Wollongong Ana Heitor – PhD Candidate, UoW Characterization of compacted soil using non-destructive methods

[Fri 18 November] Newcastle Dr Shanyong Wang – UoN 3D experimental and numerical study of the fracture initiation, propagation and coalescence behaviour of heterogeneous rocks with single or multiple fissures

[Tue 22 November] Wollongong Dr Olivier Buzzi – UoN

Influence of calcium leaching on the behaviour of rock concrete interfaces

[Fri 25 November] NewcastleOmid Kardani – PhD Candidate, UoN Iterative methods for solving large sparse linear systems arising from computational plasticity problems

[Fri 30 November] UWA Christina Rudolph – Hamburg University of Technology, Germany Investigations on the behaviour of piles under cyclic lateral loading

[Thu 1 December] Newcastle Dr David Masin – Charles University in Prague Fundamentals of hypoplasticity


RESEARCH SEMINARS

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SELECTED ACHIEVEMENTS

Britta Bienen was promoted to the rank of Associate Professor.

Olivier Buzzi was awarded the Pro-Vice Chancellor’s Award for Research Excellence.

Olivier Buzzi was awarded an Outstanding Young Investigator Award at the 13th IACMAG Conference, Melbourne, Australia.

Olivier Buzzi was selected as the Australasia representative on the ISSMGE Technical Committee of the International Group of Rock Mechanics.

Antonio Carraro was recruited as a Research Academic in the CGSE and will commence early in 2012 at UWA.

John Carter, in collaboration with Jinchun Chai (Saga, Japan), published the book Deformation Analysis in Soft Ground Improvement.

John Carter was appointed as a Member of Sectional Committee 5, Applied Physical and Engineering Sciences, Australian Academy of Science, for the period 2011-2013.

Mark Cassidy was appointed to the ARC College of Experts.

Mark Cassidy was appointed as The Lloyd’s Register Educational Trust Chair of Offshore Foundation Systems.

Anna Giacomini was appointed as a Research Academic in the Priority Research Centre for Geotechnical and Materials Modelling.

James Hambleton was appointed as a Research Academic in the CGSE at the Newcastle node.

Shazzad Hossain was elected as a Core Member of ISO TC67/SC7/WG7 (International Organization for Standardization: site-specific assessment of mobile offshore units – Jack-ups).

Shazzad Hossain and Mark Randolph were awarded the Institution of Civil Engineers (ICE) Offshore Award for their paper “Deep-penetrating spudcan foundations on layered clays: numerical analysis.” Géotechnique, 60(3), 171-184, 2010. This award is given to the paper that has been decided by the ICE award panel as the best paper published in Géotechnique in 2010 in the offshore category.



52

Shazzad Hossain and Mark Randolph were awarded the Institution of Civil Engineers (ICE) David Hislop Award for 2010. This award is for the best paper published in the Proceedings, or in an Institution conference volume, on heavy marine design and construction with particular reference to offshore engineering.

Shazzad Hossain was awarded the D.H. Trollope Medal for 2010 by the Australian Geomechanics Society for his papers: “Deep-penetrating spudcan foundations on layered clays: centrifuge tests.” Géotechnique, 60(3), 157-170, 2010 and “Deep-penetrating spudcan foundations on layered clays: numerical analysis.” Géotechnique, 60(3), 171-184, 2010. The Medal is awarded to a member of the Society who is the author of an outstanding paper on either theoretical or applied Geomechanics, on a biannual basis, based on recent or current doctoral research.

Jinsong Huang was appointed as a Research Academic in the CGSE at the Newcastle node.

Mina Kardani completed a PhD and was appointed as a Research Associate in the CGSE to work in the area of dynamic soil-structure interaction.

George Kouretzis was recruited as a Research Academic in the CGSE and will commence early in 2012 at Newcastle.

Kristian Krabbenhoft was elected as the Australian representative on the ISSMGE Technical Committee on Safety and Serviceability.

Xu Li was appointed as a Research Associate in the CGSE at UWA.

Andrei Lyamin received an Excellent Contributions Award from the International Association for Computer Methods and Advances in Geomechanics (IACMAG). The award was for his “pioneering work on finite element limit analysis analysis.”

Richard Merifield received an Excellent Contributions Award from the International Association for Computer Methods and Advances in Geomechanics (IACMAG). The award was for “developing design methods to predict the stability analysis of slopes, foundations and anchors in both soil and rock.”

Richard Merifield was promoted to the rank of Associate Professor.

Richard Merifield was appointed to the Editorial Boards of the Canadian Geotechnical Journal and Computers and Geotechnics.

Conleth O’Loughlin was recruited as an Associate Professor in the CGSE and will commence early in 2012 at UWA.



53

Mark Randolph was elected as a Fellow of the Royal Society.

Mark Randolph and Susan Gourvenec published the book Offshore Geotechnical Engineering.

Scott Sloan was invited to give the 51st Rankine Lecture in March 2011 by the Institution of Civil Engineers London. This is the highest accolade that can be bestowed on a geotechnical engineer.

Scott Sloan was appointed Chair of Sectional Committee 5, Applied Physical and Engineering Sciences, Australian Academy of Science.

Sam Stanier was appointed as a Research Associate in the CGSE at UWA.

Chet Vignes was recruited as a Research Academic in the CGSE and will commence early in 2012 at Newcastle.

Cristina Vulpe was recruited as a Research Associate in the CGSE and will commence early in 2012 at UWA.

David White received the Western Australian Early Career Scientist of the Year Award at the 2011 WA Science Awards. The award was “to honour outstanding achievements in WA science”.

David White was winner of the 2011 Western Australian Tall Poppy Science Award. The award was “to recognise Australian scientific excellence”.

David White (with colleagues Liang Cheng and Hongwei An from the School of Civil & Resource Engineering at UWA) was a winner of the Woodside Encouragement Prize at the WA Innovations 2011 Awards, for their O-tube research project.

David White was appointed to the Géotechnique editorial sub-panel for the 2012 Special Issue on offshore geotechnics.

Chao Yang was appointed as a Research Academic in the CGSE at the Newcastle node.

Bassem Youssef completed a PhD and was appointed as a Research Associate in the CGSE at UWA.



54

EXTERNAL FUNDING AWARDED

The Chief Investigators and Associates affiliated with the CGSE were successful in winning the following grants (only those relevant to the Centre are shown)

The CGSE led a successful bid for a Linkage Infrastructure, Equipment and Facilities grant to develop a National Geotechnical Centrifuge Facility. This project is a national collaboration between The University of Western Australia (lead node), The University of Newcastle, The University of Wollongong, Monash University, The University of Adelaide and The University of Queensland. The grant of $700,000, together with additional funding provided by the project partners, will enable a new 10 metre diameter geotechnical centrifuge to be installed at UWA. This will form an integral part of the CGSE research on the modelling of complex offshore and onshore structures.



55

Lachlan Bates attracted $208,512 in external funding from various industry sources (including Ausgrid Aurecon Australia Pty Ltd, Coffey Geotechnics Pty Ltd, Douglas Partners, Golder Associates Pty Ltd, Parsons Brinkerhoff Australia Pty Ltd, GHD, Menard Bachey Pty Ltd, Keller Ground Engineering Pty Ltd, Frankipile Australia Pty Ltd, Transpacific Industrial Solution, John Holland Group Pty. Ltd) for advanced in situ soil testing using the NEWSYD mobile facility.

Britta Bienen received $93,690 from TU Hamburg-Harburg to investigate the tendency for pile plugging during installation, depending on the installation method and relative sand density.

Britta Bienen received $40,000 from TU Hamburg-Harburg to investigate the tendency for pile displacement accumulation, when subjected to varying cyclic loading.

Britta Bienen and Mark Cassidy were awarded $330,000 for a 4 year ARC Discovery Grant entitled “Predicting the foundation performance of offshore jack-up drilling rigs in intermediate soils.” A Postdoctoral Fellowship was funded for Dr Bienen.

Christophe Gaudin and David White received $182,180 from Inpex for centrifuge modelling of gas export pipeline-soil interaction.

Christophe Gaudin and Mark Cassidy received $31,750 from the University of Maine to research the design of mooring systems for floating offshore wind turbines.

Susan Gourvenec and Mark Randolph received $114,400 from Subsea 7 (formerly Acergy) for mudmat design under general multi-dimensional loading.



56

Buddhima Indraratna and Cholachat Rujikiatkamjorn were awarded $455,000 for a 3-year ARC Linkage project on “Cyclic behaviour of unstable soils stabilised by lignosulfonate with special reference to rapid transport infrastructure.”

Kristian Krabbenhoft was awarded $813,192 for a 5-year ARC Future Fellowship to tackle “Complex granular flows.”

Mark Randolph and Dong Wang were awarded $640,000 for an Australian Research Council Discovery Grant entitled “Dynamic evolution of submarine slides and consequences for offshore developments.” A Discovery Outstanding Research Award was funded for Professor Randolph and an International Collaboration Award was funded for Professor Alexander Puzrin from ETH Zurich.

Shazzad Hossain, Mark Randolph and Mark Cassidy were awarded $409,904 for a 3 year Australian Research Council Linkage Grant entitled “Estimation of spudcan penetration resistance in stratified soils directly from field penetrometer data and quantification of punch-through risk.” A Postdoctoral Fellowship was funded for Dr Hossain.

Shanyong Wang and Cholachat Rujikiatkamjorn were each awarded a 3-year ARC Centre of Excellence ECR Researcher Support Award. The total value of these awards was $1,242,444 and they will be used to investigate “Ground improvement methods for soft and problematic soils,” which is a key focus of the CGSE.

David White and Christophe Gaudin were awarded $331,325 from BP for centrifuge modelling of pipe-soil interaction.

David White and Christophe Gaudin were awarded $331,250 from Woodside for centrifuge modelling of lateral pipe-soil interaction.

David White was awarded $105,000 from Atkins Boreas for axial and lateral pipe-soil interaction within the SAFEBUCK GEO JIP.



57

SELECTEDRESEARCH PROJECTS


SELECTED RESEARCH PROJECTS

58

GRANULAR CONTACT DYNAMICS

Key Researchers: Kristian Krabbenhoft, Andrei Lyamin, Jinsong Huang, Mario Vicente da Silva, Scott Sloan

Perhaps the most reliable and direct way of modelling the behaviour of granular materials is to account for the motion and interaction the individual particles that make up the material. This is the basic idea behind the discrete element method (DEM) which has been applied extensively in geotechnical engineering and related fields as an alternative to continuum models. Besides the limitation that the particle geometries are idealized as spheres or other simple geometric shapes, the main drawback of the DEM is the computational time required which easily exceeds days or weeks for typical problems of practical interest.

Considering a collection of particles, the DEM works by first advancing the particle positions in an explicit manner according to Newton’s second law of motion. Next, the overlap that may occur as a result of this is countered by applying repulsive forces according to an elastic law relating force and particle overlap. This approach requires very small time steps to maintain stability.

Alternatively, it is possible to cast the governing equations in a time-implicit manner where both the particle displacements and the contact forces appear as the unknowns. The task is then to solve for the displacements while ensuring that the contact forces are of a magnitude that exactly prevents inter-particle penetration. This is the basic idea behind the new granular contact dynamics (GCD) scheme developed by CIs Kristian Krabbenhoft and Andrei Lyamin in collaboration Associates Jinsong

Huang and Mario Vicente da Silva (who is from the New University of Lisbon, Portugal and is spending his sabbatical year at the Centre).

In contrast the conventional DEM, the GCD scheme allows for much larger time steps. It further comes in a static version that efficiently addresses problems where the time scales are such that dynamic effects are negligible. Examples include common soil mechanics laboratory tests such as triaxial tests, quasi-static cone penetration, and various applications in the earth sciences where the time scales are such that the deformations are of a quasi-static nature.

The most basic GCD scheme operates with rigid spherical particles that interact via frictional contact (see Figure 1). Although this model has its natural limitations, it is attractive due to its simplicity, requiring only a single material parameter as input, namely the inter-particle friction coefficient. Starting from the basic rigid-frictional model, a number of more advanced models have been developed. These models include features such as nonlinear particle elasticity, viscous drag (for particles immersed in a fluid with a significant viscosity), and a novel three-dimensional model for rolling resistance which takes the effects of non-spherical particle geometries into account and allows for accurate simulation of natural granular materials such as sands without modelling the particle geometries in detail.

So far, the scheme has been validated, qualitatively and quantitatively, for a large number of benchmark problems. An example is shown in Figure 2 where the static version of the scheme has been used to simulate a true triaxial test. As seen, the peak shear strength is highly dependent on the initial packing while, at sufficiently large strains, a unique critical state strength is obtained.


SELECTED RESEARCH PROJECTS – GRANULAR CONTACT DYNAMICS

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FIGURE 1: Frictional contact between two spherical particles. FIGURE 2: Results of true triaxial tests on granular assemblies.

Another problem that has been dealt with quite extensively and used for validation of the new scheme is that of the collapse of granular columns, an example of which is shown in Figure 3. This problem has also been used to validate a continuum model for granular flows.

Finally, in order to accommodate large-scale simulations a number of parallelization strategies have been developed. One such strategy uses ideas previously adopted in computational limit analysis applications. Considering a collection of particles, a domain decomposition is performed (see Figure 4) such that the task of solving the governing equations for each domain is assigned to an independent processor. This strategy has proved quite efficient and typically handles problems with around 1 million particles in about a week using a 100 core cluster. Further developments, particularly using General Purpose Graphic Processing Units (GPGPU) is expected to dramatically reduce this time so that problems with a few million particles can be solved in a matter of hours.


SELECTED RESEARCH PROJECTS – GRANULAR CONTACT DYNAMICS

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FIGURE 4: Partitioning of granular assembly for parallel processing.

FIGURE 3: Granular column collapse and comparison with continuum model (red line).

DYNAMIC COMPACTION GROUTING

Key Researchers: Shanyong Wang, Scott Sloan, Buddhima Indraratna, John Carter, Cholachat Rujikiatkamjorn

The main objective of this research is to develop an efficient, environmentally friendly, and highly flexible method for improving the density and strength of soils, which is known as Dynamic Compaction Grouting (DCG).

The basic concept for DCG is shown in Figure 1. This new technique introduces vibrations to the membrane of the grouting bag during the expansion/compaction process (Figure 1(b)). Unlike static compaction grouting (Figure 1(a)), the surrounding soil is not only compacted by the expanding membrane, but also by the membrane waves generated in the soil. The expansion of the membrane fills the voids that are created by the decrease in volume of the soil as a result of the densification process. This prevents loss of ground during the densification process, and minimises disturbance to surrounding structures.

In the project, laboratory scale grouting tests will be performed to identify the critical controllable factors of DCG so that compaction effectiveness can be optimised. In addition, a Modified Cam Clay model for cyclic loading will be implemented in ABAQUS to simulate the soil behaviour under dynamic compaction grouting. Finally the data from an extensive suite of experimental tests will be compared with the finite element predictions to validate the theory.

FIGURE 2: Schematic of dynamic compaction grouting apparatus.

Laboratory Tests The objective of the laboratory tests will be to study the fundamental mechanism of dynamic compaction grouting and the associated soil densification effect. The proposed laboratory grouting testing setup is shown in Figure 2. An important characteristic of the setup is that it can simulate dynamic compaction grouting in soils under triaxial conditions. In these tests, the effective confining pressure, lateral earth pressure coefficient (K0), excess pore water pressure, back pressure, void ratio change, as well as the vertical and lateral deformation of the specimen will be measured. In addition, the dynamic compaction grouting pressure, the dynamic compaction frequency, the dynamic compact grouting amplitude, and the dynamic compaction grouting period will be controlled.


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FIGURE 3: Pressure pulse schematic.FIGURE 1: Schematic static and dynamic compaction grouting.

The pressure pulsing device is a critical piece of equipment. The mechanics of pressure pulsing is the reverse of a combustion engine where rotary motion is converted to a vertical movement of a piston (Figure 3). A motor speed controller is used to control the speed of the pistons movement,which then controls the frequency of the vibrations.

The movement of the piston forces fluid to move in and out of the cylinder, which in turn causes the membrane inside the soil to vibrate. As a result, energy is transferred to the surrounding soil and densifies it.

Numerical AnalysesThe finite-element code ABAQUS will be used to perform the numerical simulations of static and dynamic compaction grouting. The soil is modelled as a multiphase material and effective stresses are adopted to describe its behaviour. Figure 4 shows the numerical model setup, which assumes axisymmetry.

An anisotropic modified Cam Clay model for cyclic loading will be incorporated into ABAQUS to investigate the behaviour of loose soil under dynamic compact grouting. Figure 5 shows the behaviour of this model under

FIGURE 5: An anisotropic modified Cam Clay model for cyclic loading.

repeated consolidation and swelling. The model will be implemented in ABAQUS through its user subroutine UMAT. A parametric study will then be performed to investigate the influence of dynamic frequency, dynamic amplitude, and dynamic period on both the efficiency of the soil mass. The numerical results of the parametric study will be validated by experimental results, thus allowing the degree of soil improvement by the DCG method to be identified. Finally, numerical simulations for practical problems using DCG will be conducted. The results of this integrated study will provide a valuable method to engineers for ground improvement. A series of charts and design recommendations will be developed.


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FIGURE 4: Finite element axial-symmetric mesh and boundary conditions for static/dynamic compaction grouting tests.

SCREW ANCHOR FOUNDATIONS

Key Researchers: Richard Merifield, Andrew Abbo, Dong Wang, Christophe Gaudin, Yuxia Hu

Screw piles, also known as helical piles or screw anchors, are used as a foundation system to sustain tensile, compressive, and/or lateral loads. They are composed of a number of helical plates welded along a central shaft, as illustrated in Figure 1.

The usage of screw anchors in Australia is gaining popularity and, although they have been successfully used in domestic applications for years, their behaviour is not well understood. Moreover, the methods used by manufacturers and engineers for estimating screw pile capacity lack engineering acceptance and geotechnical rigor.

The primary aim of this research project is to use a combination of numerical modelling, physical modelling, and field testing techniques to better understand multi-helix screw pile foundation behaviour in a range of applications and soil types. A practical design framework for helical pile foundations will be established to replace existing semi–empirical design methods that are inadequate and have been found to be excessively under or over conservative. This framework can

FIGURE 2: Applications for screw anchors.

then be used by design engineers to confidently estimate the capacity of multi–helix screw piles for engineering projects.

Significance In recent years, the use of helical anchors has expanded beyond their traditional use in the electrical power industry. The advantages of rapid installation and immediate loading capability have resulted in their being used in more traditional civil engineering applications. They are now used as foundation systems for new construction, tie downs for structures subject to uplift, and tiebacks for the retention of slopes and walls. Some example applications of helical anchors are shown in Figure 2.

Unfortunately, our current understanding of these


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FIGURE 1: Typical Screw Anchor. FIGURE 3: Model Screw Anchor.

anchors is unsatisfactory and the underlying theoretical framework adopted by engineers has proven to be largely inappropriate and inadequate. A better understanding of the behaviour of helical anchors will lead to increased confidence in design, their wider acceptance as a foundation alternative, and more economic and safer designs.

Testing Methodology This project will exploit the strengths of the Newcastle and UWA nodes of the CoE, and enable a fully integrated approach to be adopted that will include:

1. Advanced numerical analysis

2. Full scale field testing

3. Centrifuge testing

4. In-situ soil characterisation

For a helical anchor with specified geometry, the undrained uplift capacity depends on not only the soil strength profile but also the overburden pressure imposed on the anchor. For this reason, the observed collapse mechanism is often different in small-scale 1g model tests in clay, where the over-burden pressure is negligible relative to the ultimate uplift capacity. The purpose of our centrifuge tests is to observe the entire pull-out process of helical anchors and to study the capacities against non-uniform strength profiles.

Preliminary work has already been undertaken for anchors in clay using large displacement finite element analyses and the geotechnical centrifuge at 100g. A sample model anchor is shown in Figure 3.

A typical measured load-displacement curve for twin-helix anchors is shown in Figure 4.

FIGURE 5: Predicted displacements at failure for various screw anchors.

Preliminary numerical analyses confirm that the failure mechanisms for these types of foundations is complex, as indicated by the contours of displacement for a range of twin-helix anchors with different embedment depths and anchor spacings in Figure 5.


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FIGURE 4: Responses of anchors in centrifuge.

OFFSHORE FOUNDATIONS AND ANCHORS

Key Researchers: Majid Nazem, Kristian Krabbenhoft, Britta Bienen, Mark Cassidy, Mark Randolph, Richard Merifield, Wojtek Solowski, Christophe Gaudin, Dong Wang

In many offshore engineering problems, soil undergoes large deformations while interacting with a structure under static, geostatic, or dynamic loads. Examples include the installation of a spudcan foundation, the penetration of a torpedo anchor into the seabed, the investigation of the pullout capacity of anchors embedded in soil, and the estimation of soil properties using devices such as a cone penetrometer, a T-bar, or a ball penetrometer. Due to their extremely complex and nonlinear nature, purely analytical solutions for such problems do not exist in the literature. Numerical methods, on the other hand, can take advantage of superfast computers and are very suitable for the analysis of offshore foundation problems. Owing to extremely large deformations, the highly nonlinear behaviour of soil, the presence of pore water pressures, the changing boundary conditions, and, in some cases, dynamic forces, many current numerical methods fail to tackle such problems accurately and efficiently. Advanced new algorithms, tailored to the problems at hand, need to be developed.

Over the past two decades, the geotechnical research group at The University of Newcastle has developed a finite element code, SNAC, for analysing complex geotechnical problems. SNAC takes advantage of the Arbitrary Lagrangian-Eulerian (ALE) strategy as well as the h-adaptive finite element method. Both these methods have proven to be robust and efficient for solving large deformation problems in geomechanics. SNAC has been successfully used to solve a wide range of complex geotechnical problems including footings undergoing large deformations (Figure 1), the static and dynamic penetration of objects into

FIGURE 2: Simulation of static cone penetration test (h-adaptive FE).

soil layers (Figures 2 and 3), and finite deformation analysis of consolidating soil under loaded footings.

Nonetheless, analysing the interaction between the soil and a structure, in the presence of pore water pressures and static or dynamic loads, still remains a challenge in computational geomechanics. To numerically simulate such problems an advanced time-integration scheme is needed to solve the highly nonlinear global equations which follow from the principle of virtual work, the continuity equation, the principle of effective stress and Darcy’s law. In addition, a constitutive soil model which can consider the effects of large deformations, strain-rate, strain-softening, pore pressure accumulation under cyclic loading, inhomogeneity, and the possibility of liquefaction must be formulated.

After developing and implementing the new algorithms, the computational tool will be validated by comparing the numerical results with available experimental test data and field observations. Experimental and field data will flow from the extensive suite of centrifuge and field tests (at the Ballina test site) that will be conducted as part of the CGSE. Once the numerical tool has been validated, it will be employed to study offshore geotechnical problems in more detail. Among other potential applications, the project will focus on the numerical simulation of spudcans, torpedo anchors, and the penetrometers used for site-investigation purposes. Each of these cases is briefly explained in the following.


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FIGURE 1: Large deformation analysis of an undrained soil under a footing (ALE).

Spudcans: Spudcans form the foundation of mobile jack-up rigs which are widely used in offshore drilling, exploration and site investigation. The main goal here is to conduct a parametric study to find out the effect of key parameters on the capacity of the soil surrounding the spudcans. These parameters include the installation rate, the mechanical and hydraulic properties of the soil, the consolidation time, and the geometry of the spudcan. In addition, it is also important to study the failure mechanisms due to spudcan penetration into a strong soil layer overlying a weak layer.

Torpedo anchors: Torpedos are a new anchoring system developed for tethering buoyant facilities in deep water. Torpedo anchors, usually 12-15 m long, are deployed from a ship and penetrate to a depth of 20 to 35 m below the mudline under the action of their own kinetic energy. The soil fills the gap created above the anchor, and then starts to consolidate. This project will investigate the behaviour of torpedo anchors including the penetration phase and the following consolidation phase, as well as the resultant pullout capacity. Among other factors, the important parameters included will be the geometry of the anchor, its weight and impact velocity, the mechanical properties of the soil and its permeability, and the consolidation time allowed.

Penetrometers: Penetrometers are widely used for site-investigation purposes in both on shore

and offshore engineering, but are challenging to analyse. In offshore engineering, the piezoball penetrometer is able to determine the soil type and provide data on consolidation characteristics of the soil. Such information may be used to estimate the hydraulic and mechanical properties, which are crucial for geotechnical design. To achieve this goal, however, validated relations between the penetration measurements and soil properties are required. The advanced finite element formulations developed as a part of this project will be used to conduct a parametric study to correlate the penetrometer properties, such its geometry and the penetration rate, to the soil properties including the stiffness, the shear strength, and the permeability.

In summary, this project involves extensive collaboration between two nodes of the Centre, The University of Newcastle and The University of the Western Australia. The complimentary skills of the two nodes will permit a wide range of offshore engineering problems to be studied in detail, both numerically and experimentally.


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FIGURE 3: Dynamic penetration of an object into a soil layer (ALE).

USE OF SEPLAS AS A PERMANENT MOORING SOLUTION

Key Researchers: Christophe Gaudin, Mark Randolph, Mark Cassidy, Yinghui Tian, Dong Wang, Richard Merifield

As oil and gas developments move off the continental slopes into water depths exceeding 1000m, novel anchor systems are required for permanent mooring of floating processing facilities. The CGSE has been investigating a number of deep water options, including Suction Embedded PLate Anchors (SEPLA).

SEPLAs have been developed to answer the growing need for anchors to withstand significant vertical loading. The concept combines the advantage of suction caissons (known penetration depth and location) and ‘drag-embedded’ plate anchors (efficiency and low cost). The plate anchor is housed initially within a slot at the tip of a suction caisson (also called a follower). The anchor is embedded by pumping out the water inside the suction caisson. When the targeted depth is reached, the pump flow is reversed, and the caisson retrieved, leaving the SEPLA in place in a vertical inclination. The slack mooring chain attached to the anchor padeye is then tensioned, causing the SEPLA to rotate, in a process known as keying, to an inclination that is, for a symmetric anchor, approximately normal to the local chain orientation. A photo of an offshore SEPLA is provided (Figure 1).

Before SEPLAs can be used regularly for permanent installations, a number of research issues need to addressed. These include, (i) during the keying process, as the anchor is first loaded, what is the loss of embedment and reduction in capacity?, (ii) what is the long-termed sustained loading capacity?, and (iii) what is the operational cyclic loading capacity?

In an integrated project, initially funded by ExxonMobil in Houston, these questions were addressed through centrifuge testing, large deformation finite element analysis and analytical developments.

The centrifuge testing process mimicked both the installation and operation of the anchor and provided insights into (i) the keying of the anchor and the associated loss of embedment, (ii) the combined effect of consolidation and strain softening during sustained loading and the

FIGURE 1: Offshore SEPLA.

associated loss or gain in capacity and (iii) the cyclic degradation under various levels of cyclic loading. A model anchor was manufactured from stainless steel, replicating at a scale of 1/150th all the features of a typical SEPLA, including the shank and the keying flap (Figure 2). Although the dimensions became small, particular attention was paid to modelling the position of the padeye and the eccentricity of the hinge of the keying flap correctly. PIV tests were also conducted to trace the displacement trajectory during keying.

Using these results, an analytical plasticity model, named Chain And Selpa Plasticity Analysis (CASPA), has been developed to allow a quick prediction of the trajectory and load development during anchor keying and up to peak load. Perfect plasticity is assumed, allowing the kinematics of the anchor to


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FIGURE 2: Model SEPLA.

FIGURE 3: Example centrifuge result.

be determined from a yield surface and associated plastic potential. In CASPA the trajectory and performance of a typical SEPLA can be predicted using the model and its application has been verified though comparison with results from the centrifuge tests (Figure 3). Further analytical results indicate that the loss of embedment can be reduced significantly by increasing the offset, but at the detriment of the ultimate anchor capacity.

In the current industry design, a keying flap is widely employed with the aim of reducing embedment loss. In centrifuge tests and large deformation finite element analyses this flap has been shown to not work as expected (and have christened it the “cane toad of the anchor world”). Further numerical simulations have been conducted (Figure 4) to explore the flow mechanism of the keying flap and these have identified the problem with the current flap and a new design that opens during keying (limiting loss of embedment) but closes during sustained loading (maximising capacity) has been suggested.


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FIGURE 4: SEPLA and keying flap.

The team of Christophe Gaudin, Mark Randolph, Mark Cassidy, Yinghui Tian and Dong Wang is continuing this research, with current investigations concentrating on defining the changing yield surface size and shape with protruding shank geometry, alignment of analytical and large deformation finite element results, developing an analytical method to predict sustained and cyclic capacity, and application of SEPLAs in Australian deep water calcareous muds.

SPUDCAN PUNCH-THROUGH

Key Researchers: Mark Cassidy, Sam Stanier, Dong Wang, David White, Mark Randolph, Majid Nazem, Yuxia Hu, Shazzad Hossain, Pan Yu, Xu Li, Stefanus Safinus, Jingbin Zheng

In the shallow water offshore oil and gas industry, punch-through of spudcan foundations is still the most frequent cause of failure for jack-up platforms. This phenomenon arises during preloading of the jack-up on soil stratigraphies incorporating strong layers in generally soft material. The thin layers of strong material cause a transient increase in penetration resistance, which diminishes as the spudcan foundation penetrates past the stiff layer. This can cause uncontrolled penetration of the jack-up leg being preloaded, potentially causing damage to the jack-up leg or toppling of the jack-up structure. These failures or periods of downtime are very costly and hazardous to operators. Therefore accurately predicting the risk and severity of punch-through is of great importance to the shallow water offshore oil and gas industry.

This punch-through phenomenon is being studied at the CGSE using a combination of centrifuge and numerical modelling. Punch-through of spudcan foundations on sand overlying clay strata has been studied in the drum centrifuge by Mark Cassidy, Sam Stanier and Dong Wang and their PhD student Pan Hu. A comprehensive suite of tests has been performed on loose sand overlying clay strata of varying geometries to complement existing

tests data for dense sand overlying clay strata. This data set has then been used to recalibrate an existing failure stress dependent analytical model for predicting the peak penetration resistance that was previously developed at COFS. The recalibrated model has then been validated against other existing centrifuge tests data in the literature and compared with current best industry practice in the form of the ISO 2012 guidelines. As Figure 1 shows, the newly calibrated failure stress dependent method is far superior to current best industry practice, since all forms of the current recommendations in the ISO 2012 guidelines would significantly under predict the peak penetration resistance, thus leading to underestimation of the risk of a punch-through event occurring.

One of the principal problems with predicting the potential for punch-through offshore is soil characterisation. For example when a stiff layer is observed during site investigation using a penetrometer it is difficult to know whether it is sand, clay or silt. Knowing this is important as different calculation methods are employed depending upon the type of material found. Shazzad Hossain, Mark Randolph, Mark Cassidy and Dong Wang have been working with PhD students Stefanus Safinus and Jingbin Zheng on the development of a universal design approach. This approach will be applicable to any soil profile, accounting for methodical consistency and robustness. For this purpose, a high quality field and experimental database of spudcan behaviour in layered soils is being consolidated. Centrifuge model tests and large deformation FE analyses on spudcans and cones penetrating multilayer sediments, mimicking these field data, have been undertaken and more are scheduled in 2012.

Carbonate soils, prevalent in Australian waters, are of particular interest, as the behaviour of spudcan foundations in these soils is not well understood. Characterisation of these materials is of primary importance as it provides input to the centrifuge and numerical models. Preliminary laboratory tests, including Rowe cell, Triaxial, and Simple Shear tests to identify the soil strength behaviour, have been undertaken since August 2011. A program in VB-Excel is being coded to assist the interpretation of soil layering from CPT data, extraction of relevant soil parameters, prediction of the spudcan penetration resistance profile and identification of potential punch-though.

The goal is to develop an integrated jack-up installation system as shown in Figure 2, which will allow cone penetration tests (CPT) to be performed and (based on the real time data) prediction of the spudcan penetration resistance profile to be


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FIGURE 1: Performance of recalibrated failure stress dependent model versus current best industry practice from the ISO 2012 guidelines.

made prior to preloading. This will assist jack-up operators in making decisions regarding what if any mitigation measures need to undertaken before preloading to prevent a potential punch-through hazard.

Shazzad Hossain, Yuxia Hu and Long Yu are investigating the potential to replace spudcan foundations with a skirted foundation in an attempt to mitigate the punch-through risk in sand-overlying clay deposits using both centrifuge tests and Large Deformation Finite Element (LDFE) approaches. The results of the LDFE analyses were validated against the centrifuge test data prior to undertaking a parametric study. This study covered a range within the bounds of practical interest of foundation diameters, aspect ratios of skirt depth to foundation diameter, relative thickness and density (or friction and dilation angles) of the upper sand layer and normalised strength and strength non-homogeneity of the lower clay layer. The results show that the use of alternative skirted foundations eliminated severe punch-through on the loose to medium dense sand overlying clay deposits. A skirt length to foundation diameter ratio of 0.25 was sufficient to mitigate punch-through failure as is shown in Figure 3.

FIGURE 3: Mitigation of spudcan punch-through in sand overlying clay using skirted foundations.

To compliment this body of experimental work various numerical approaches to the problem are also being developed.

Dong Wang has been developing the Coupled Eulerian Lagrangian (CEL) method in collaboration with Sam Stanier, Mark Cassidy and their PhD student Pan Hu. This method allows for large deformation in the soil, without mesh distortion induced errors, by coupling an Eulerian solution domain for the soil with a Lagrangian domain for the spudcan foundation. So far this method has been used with simple elasto-plastic Mohr-Coulomb constitutive models representing the sand clay layers. These techniques will eventually be coupled with a constitutive model for the sand that captures the dilatancy and transient peak strength of the sand layer with respect to initial relative density, such as the hypoplastic model.

David White, Yuxia Hu and Xu Li are extending the Mohr-Coulomb model using Bolton’s (1986) relationships to capture dilatancy and peak strength. This model has been incorporated into AFENA using the RITSS Large Deformation Finite Element (LDFE) Method developed at COFS. It is now being used to analyse punch-through tests on sand overlying clay strata performed in the centrifuge. Figure 4 shows the simulation of sand overlying clay spudcan punch-through tests performed in a centrifuge published in the literature versus the LDFE simulation using the Modified Mohr-Coulomb model. As the spudcan penetrates through the sand layer the dilatancy of the sand diminishes, yielding a peak penetration resistance and potential for punch-through. Further validation of the model is ongoing and it is hoped that it may be used in the future, in combination with centrifuge testing, to develop simple analytical models for practicing engineers



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FIGURE 2: CPT integrated in a spudcan foundation.

FIGURE 4: LDFE simulation of sand overlying clay spudcan punch-through compared to centrifuge data from the literature.

to assess punch-through risk in stratified samples using site investigation data.

This combination of experimental and numerical work being conducted at the CGSE is ongoing. 2012 will see a large variety of spudcan punch-through tests being performed in both the beam and drum centrifuges at UWA. These tests will look at a range of variables including but not limited to: the impact of geometry and density of sand layers inter-bedded into soft clay; the potential impact of inter-bedded calcareous layers; spudcan foundation geometry; potential of preloading holding periods causing punch-through due to consolidation; and the use of novel foundations shapes to mitigate the severity of punch-through.

Data yielded from these tests will be used to continue validation and calibration of the numerical techniques being coupled in parallel. The ultimate goal is to better equip offshore geotechnical engineers with simple analytical design tools that they can use to accurately predict punch-through events, as well as to provide tested and validated mitigation solutions when such a risk has been identified.



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LIMIT ANALYSIS OF RANDOM MATERIALS

Key Researchers: Andrei Lyamin, Vaughan Griffiths, Jinsong Huang, Scott Sloan, Mark Cassidy

By the very nature of its origins and deposition, soil is one of the most variable of all engineering materials. This variability is rarely taken into account directly in traditional geotechnical engineering design, rather some cautiously selected “characteristic value” is assumed to act across the region of interest. All potential uncertainties are then dealt with by the use of “factors of safety” when designing against ultimate or serviceability limit states. Most geotechnical designs continue to be based on the traditional working stress design (WSD) approach, however in recent years there has been a significant growth in Load and Resistance Factor Design (LRFD) approaches involving partial factors on different components of the design. In the LRFD approach, dead and live loads may be factored up, and resistances may be factored down. In the partial factor approach, different factors may apply to different components, i.e. a different factor may be applied to tan(f’) than c’ reflecting different degrees of reliability about the estimation of those parameters. The introduction of the term “reliability” suggests that a statistical approach may be valuable in choosing the resistance factors needed to achieve a minimum degree of reliability in a design.

In spite of some reluctance on the part of civil engineers to embrace probabilistic concepts, there is now a rapid growth in interest in these methods applied to geotechnical engineering.

FIGURE 2: Probabilistic approach.

Indeed, eminent academics and practitioners have raised the profile of probabilistic concepts, by explaining the methods in familiar terminology. Recent dedicated conferences have brought these concepts to a wider audience, including the insurance industry, and new textbooks, journals and conference sessions dedicated to risk and reliability have appeared.

Traditional geotechnical analysis and design, for example of a bearing capacity problem, is displayed in Figure 1. Here we input our characteristic values of f’ and c’ into Terzaghi’s bearing capacity equation, compute an ultimate bearing capacity qult and then divide by a generous factor of safety FS to give the allowable value qall.

In the probabilistic approach, still based on Terzaghi’s equation, the goal is to estimate the probability of failure as an alternative to the factor of safety. As shown in Figure 2, we input means and standard deviations of input parameters and emerge with a mean and standard deviation of the bearing capacity, from which probabilities can be estimated. Of interest to engineers, for example, would be an estimate of the probability of the ultimate bearing capacity falling below the allowable value P[qult < qall].

As can be noted in Figure 2, some probabilistic methods may also account for cross-correlation between parameters and spatial correlation (or auto-correlation). The former recognises that random input parameters may not be independent (i.e. when tan(f’) is above its mean the same may also be so for c’ or vice versa) and the latter recognises that random properties close together in the field are more likely to have similar values that those far apart.


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FIGURE 1: Traditional approach.

FIGURE 3: Typical RFEM simulations.

An obvious question is how can we best perform the operation indicated in Figure 2, in which input variability is translated into output variability? In terms of sophistication and mathematical complexity, we might identify three levels of probabilistic analysis:

1. Event trees

2. First order methods

3. Monte-Carlo simulations

Under level 3 above, we propose to build on a methodology called the Random Finite Element Method (RFEM), first developed by Griffiths and Fenton, in which random fields are used to model soil properties and combined with finite elements in a Monte-Carlo framework. The method has already been applied successfully to numerous collapse problems in geotechnical engineering using an elastic-plastic finite element algorithm. See Figure 3 for examples of RFEM bearing capacity and slope stability models.

In this project we propose to combine the random field methodology with the Upper and Lower bound finite element limit analysis (LA) algorithms developed at Newcastle. These algorithms are computationally efficient at bracketing the true collapse load of geotechnical problems through exact adherence to the upper (UB) and lower bound (LB) theorems of LA. Examples of UB solutions to bearing capacity and slope stability for homogeneous soils are shown in Figures 4.

The research will involve significant algorithm and code development in order to map random field properties onto the elements and nodes of existing

FIGURE 4: Typical upper bound limit analysis simulations.

LA programs. The results of the Limit Analysis/ Random Field (LARF) analyses will be compared with existing results obtained by elastic-plastic RFEM. Of particular interest in this investigation will be (i) analysis of the difference between the upper and lower bounds in random soils, which will itself be a positive random variable, (ii) the dependence of LARF results on the mesh pattern, with particular interest on the possibility of using adapted meshes, and (iii) the potential for improved computational efficiency by LA compared with iteration-intensive elastic-plastic FE. Even modest improvements can be greatly magnified in a Monte-Carlo context.

The goal of this project is to develop comprehensive and cost-effective methods to predict the probability density function of output quantities of interest (e.g., deformations, shakedown, capacity), which can in turn be used for a risk-based assessment of geo-structural performance.


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MODELLING EVOLUTIONARY CONTACT IN PLOUGHING AND CUTTING OF SOILS

Key Researchers: Jim Hambleton, Dave White, Sam Stanier, Richard Merifield, Kristian Krabbenhoft

Numerous applications in civil engineering revolve around displacement or removal of soil by means of ploughing and cutting. The terms “ploughing” and “cutting” both refer to processes by which deformation is induced by sliding contact with a rigid or flexible object, an example of which is shown in Figure 1.

Ploughing and cutting are differentiated, however, by whether or not separation of the material occurs, as shown schematically in Figure 2. Both processes play direct roles in earthmoving, mining, dredging, trenching, tunnelling and similar areas, and they are also relevant on the micro-structural level in soil-structure interaction, as sliding of asperities on interfacing materials (e.g. concrete and soil) can be a significant source of friction and wear.

While ploughing and cutting in metals have been investigated extensively, studies dealing with soils are limited. For both metals and soils, there is a basic lack of understanding of the unsteady regime in which the object (plough or cutter) first makes contact with the soil and then begins to slide with prescribed force or penetration. In this transient regime, the shape and location of material boundaries, as well as the stress and strain fields, evolve in time. As a consequence, basic quantities of interest such as horizontal (drag) force and penetration also change in time. Furthermore, previous studies focus heavily on ploughing and

FIGURE 2: (a) Ploughing and (b) cutting as distinct modes of deformation as an object slides over a surface.

cutting under plane-strain conditions despite the fact that the deformation is typically three-dimensional. As compared to metals, analysis of soils is also complicated by the presence of pore water, which plays an important role in offshore applications such as pipeline ploughing.

Through the use of state-of-the-art experimental methods and computational techniques, this project aims to build an understanding of the


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FIGURE 1: Ploughing of soft clay by a flat, inclined plate of narrow with.

FIGURE 3: Results of two-dimensional (plane strain) finite element simulations of a smooth, rigid wedge sliding over cohesive material. In the first stage (top), a normal force is applied without translation (i.e. indentation), and the wedge then slides from left to right. Contours show equivalent plastic strain.

FIGURE 4: Pattern of deformation observed in a three-dimensional finite element simulation of a smooth, rigid wedge of narrow width sliding over cohesive material.

evolutionary deformation occurring in ploughing and cutting of soils. In experiments, quantitative analysis of the evolving displacement field is performed using particle image velocimetry (PIV), and centrifuge testing is employed to reproduce full-scale behaviour, especially for investigation of applied problems relevant to industry. Observations from experiments are subsequently used as the basis for developing analytical models and validating results from comprehensive numerical simulations. In numerical simulations, attention is directed at implementing methods that effectively accommodate extreme deformations. These include adaptive finite element methods, meshless continuum-based approaches, and particle-based methods. Special emphasis in both analytical and numerical modelling is placed on accounting for three-dimensional deformation and the effects of pore pressure.

Figures 3 and 4 show typical results from two- and three-dimensional finite element simulations of quasi-static ploughing in cohesive material by a rigid wedge. Figure 3 highlights the evolutionary nature of the ploughing process as the wedge initially indents the material and then slides from left to right under prescribed normal force.

One can observe basic similarities and differences between plane strain (Figure 3) and the three-dimensional configuration for a wedge of narrow width (Figure 4). A significant difference is that material flows to the sides of the wedge in three dimensions, and as a consequence, relatively large penetration is maintained as the configuration approaches steady state. In plain strain, penetration in steady state is practically zero.


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APPLICATION OF PREFABRICATED VERTICAL DRAINS AND VACUUMPRELOADING

Key Researchers: Buddhima Indraratna, John Carter, Cholachat Rujikiatkamjorn, Geng Xueyu, Sanjay Nimbalkar, Shanyong Wang, Daichao Sheng, Richard Kelly, Scott Sloan

The booming population and associated development in coastal and metropolitan areas have necessitated the use of previously undeveloped low-lying areas for construction purposes. Most of the Australian coastal belt contains very soft clays up to significant depths, especially in Northern Queensland and New South Wales. The low bearing capacity and high compressibility of these deposits affects the long term stability of buildings, roads, rail tracks, and other forms of major infrastructure. Therefore, it is imperative to stabilise these soils before commencing construction to prevent unacceptable differential settlement. However, attempts to improve deep bearing strata may not be commensurate with the overall cost of the infrastructure. In the past, various types of vertical drains such as sand drains, sand compaction piles, prefabricated vertical drains (PVDs which are geo-synthetic), stone columns, and gravel piles have commonly been used. Certain types of granular piles and deep stone columns may indeed enhance significantly the load capacity of the soil. However, flexible PVDs have gained in popularity in recent years as they pose a lower risk of damage to existing utilities from lateral ground movement and are significantly cheaper than other alternatives. Moreover, their installation can significantly reduce the preloading period by decreasing the length of the drainage path, sometimes by a factor of 10 or more. Just as importantly, PVDs can be installed very quickly with minimum environmental implications and quarrying requirements.

Preloading is one of the most successful techniques for improving the shear strength of low-lying areas because it preloads the ground surface to induce a greater part of the final settlement that it is expected to occur a long time after construction has finished. In order to control the development of excess pore pressure, a surcharge embankment is usually raised in multiple stages, with “rest” or “consolidation” periods between the loading stages. Since many compressible low-lying soils have very low permeabilities and occur in thick beds, a lengthy time period is usually needed to achieve the desired primary degree of consolidation (>95%). In these instances, the

FIGURE 1: Spring analogy of vacuum consolidation process: (a) under fill surcharge; (b) under vacuum load.

height of the surcharge can be excessive from an economic perspective and also causes stability problems. One drawback of the surcharge technique is that the preload must be applied for a sufficiently long period, which may at times become impractical due to stringent construction schedules and deadlines. When PVDs are combined with surcharge preloading, a much shorter drainage path in the radial direction is provided, which reduces the required preload period significantly. PVDs are thus cost effective and can be readily installed in moderate to highly compressible soils (up to 40 m deep) that are normally consolidated or lightly over-consolidated. PVDs are less effective if installed in heavily over-consolidated clays.

Vacuum pressure may also be used to enhance the efficiency of PVDs. Negative pore pressures (suctions) distributed along the drains and on the surface of the ground accelerate consolidation, reduce lateral displacement, and increase the effective stress. This allows the height of the


SELECTED RESEARCH PROJECTS – APPLICATION OF PREFABRICATED VERTICAL DRAINS AND VACUUM PRELOADING

76

FIGURE 2: Instrumentation layout for the test embankments at Ballina Bypass.

surcharge embankment to be reduced, thus reducing the likelihood of instability and lateral movement in the soil. This approach is designed to distribute the vacuum (suction) pressure to deep layers of the subsoil, and can be explained by a spring analogy (Figure 1). In the context of conventional surcharge preloading, the effective stress increases due to the suction (negative) pressure, while the total stress remains the same.

Although PVDs combined with vacuum preloading are widely used in practical ground improvement projects, e.g. the Ballina Bypass (Figure 2) and the Port of Brisbane (Figure 3), the predicted behaviour is often at variance with the observed behaviour.

In practice, railway tracks and airport runways are constantly subjected to relatively high cyclic loads that build up pore water pressures in the underlying subsoil unless sufficient drainage is provided. Laboratory experiments indicate that cyclic pore pressures build up rapidly under high frequency loading, and that these pressures can be dissipated effectively using PVDs. Monitoring of the Sandgate site (near Newcastle) has been performed where relatively short drains were installed to stabilise a rail track constructed on at least 30 m


SELECTED RESEARCH PROJECTS – APPLICATION OF PREFABRICATED VERTICAL DRAINS AND VACUUM PRELOADING

77

of soft estuarine clay. As the vertical load from 25 tonne axle trains is borne mainly by the shallow subgrade, relatively short PVDs were adequate to dissipate the cyclic excess pore water pressure. Moreover, the short PVDs also contributed to the control of the lateral displacements in the shallow soft estuarine clay, having effectively consolidated it within a period of a few months. In this case, no external surcharge fill was used as preloading and no vacuum application was required as only the shallow clay layer immediately beneath the ballast and sub-ballast warranted stabilisation.

It is clear that PVDs, combined with vacuum and surcharge preloading, is a highly effective approach for ground improvement. However, analytical and numerical modelling of vacuum preloading is a difficult problem, and there is often a significant discrepancy between the predicted and observed performance of embankments stabilised with vertical drains and vacuum pressure. This discrepancy can be attributed to numerous factors such as the uncertainty of soil properties, the effect of smear, inaccurate assumptions about the soil behaviour and the vacuum pressure distribution, and the usual simplification of the 3D drainage pattern to a 2D plane strain one.

FIGURE 3: Vacuum at Port of Brisbane.

CYCLIC LOADING OF TRANSPORT INFRASTRUCTURE

Key Researchers: Buddhima Indraratna, John Carter, Cholachat Rujikiatkamjorn, Geng Xueyu, Sanjay Nimbalkar, Shanyong Wang, Daichao Sheng, Richard Kelly, Scott Sloan, Andrei Lyamin

In Australia, railways form the largest worldwide network for public and freight transportation. Given the increased demand for freight transport from the mining and agriculture industries, and for greater public transport via trains due to increased fuel costs, heavier cyclic loading on existing tracks is now inevitable. This leads to progressive deterioration and densification of the ballast and, consequently, to a loss of track geometry and differential track settlement. This in turn affects the safety and efficiency of rail tracks, and often results in speed restrictions and more frequent maintenance. This problem is most severe under high impact loads with rail or wheel imperfections, as it accelerates the breakage of ballast. The current research program aims to provide a comprehensive insight into the geotechnical behaviour of ballast under cyclic and impact loading, and to assess the relative benefits of various types of synthetic grids and shock mats for enhanced track longevity.

FIGURE 2: Typical impact force responses.

Performance Improvement of Railway Ballast Using Shock MatsThe impact testing equipment consists of a free-fall hammer of 5.81 kN weight that can be dropped from a maximum height of 6 m with an equivalent maximum drop velocity of 10 m/s (Figure 1). To eliminate any surrounding ground motion, the rig rests on a strong isolated concrete foundation (5.0 m x 3.0 m x 2.5 m) that is designed to have a significantly higher fundamental frequency. The transient impact forces are recorded by a dynamic load cell (capacity of 1200 kN) mounted on the drop-weight hammer. The load cell and accelerometers are connected to a computer controlled data acquisition system.

The impact load-time history under a single impact load (1st drop of the free-fall hammer) is shown in Figure 2. Two distinct types of peak forces occur; an instantaneous sharp peak P1 with a high frequency and P2, a gradual peak of smaller magnitude with a lower frequency. These peak forces, P1 and P2, need to modelled in order to better understand the mechanics that govern track behaviour. This, in turn, will lead to improved track designs.

Field Tests on Instrumented Track at Bulli, NSWIn order to investigate vertical and lateral track deformations and the benefits of using geosynthetics, a field trial was carried out on a instrumented track. Fresh ballast (Cu = 1.5) and recycled ballast (Cu = 1.8) without geosynthetic reinforcement were used, while the two other sections were built by placing a geocomposite layer at the ballast-subballast interface (Figure 3). The geocomposite layers consisted of bi-axial geogrids placed over the non-woven polypropylene geotextile layers.


SELECTED RESEARCH PROJECTS – CYCLIC LOADING OF TRANSPORT INFRASTRUCTURE

78

FIGURE 1: Drop weight impact testing equipment.

FIGURE 3: Installationof geocomposite at time of track construction at Bulli site.

A typical plot of vertical cyclic stress transmitted to the ballast under an axle load of about 25 tons and a train speed of about 60 km/h is shown in Figure 4. While most of the maximum vertical cyclic stresses were under 230 kPa, one peak reached 415 kPa. This high magnitude of stress was associated with a wheel flat, which proved that large dynamic impact stresses can be generated in the ballast by wheel imperfections. This fact should be carefully assessed and accounted for in the design and maintenance of ballasted track beds.

Field Tests on Instrumented Track at Singleton, NSWTo investigate the performance of different types of geosynthetics and to improve the overall track stability under field conditions, an extensive study is being undertaken on instrumented track sections near Singleton, NSW. Nine fully instrumented experimental track sections were constructed on three subgrades with distinctly different values

FIGURE 5: Reinforcement of track substructure with different types of synthetic materials.

of stiffness (Figure 5). Permanent and transient strains in the ballast, together with the variation in the vertical stresses, were routinely monitored.

Strain gauges were used to study the deformations and mobilised forces along the geogrid layers (Figure 6).

An elasto-plastic finite element model of a composite multi-layer track system has been developed (Figure 7), and its predictions compared with observed behaviour (Figure 8).

The model uses a special modified flow rule that considers the energy consumption due to particle breakage during shear deformations:



79

FIGURE 4: Cyclic stresses induced by coal train with wagons. FIGURE 6: Installation of strain gauges at Singleton.

FIGURE 7: FE mesh discretisation of a rail track.

The slight deviation between the FE predictions and the field data, shown in Figure 8, is partially due to the fact that the wheel loading is approximated by an equivalent plane strain analysis in the FE studies. Nevertheless, considering the limitations of the constitutive model, this level of agreement is encouraging and will help improve practical track design.



80

FIGURE 8: Comparison of vertical displacement (Sv) with FE predictions.


ANNUAL WORKSHOP

81

ANNUAL WORKSHOP

Following an open invitation, Centre delegates gathered in Newcastle on 14 and 15 February 2011 for the first annual workshop. The workshop provided an opportunity for staff and students from each node to present current research and discuss plans for future collaborative projects. The two-day programme consisted of opening comments by Scott Sloan, twenty-eight technical presentations, closing comments by Mark Cassidy and coordinated social events including a workshop dinner and a surf session at Newcastle Beach.

Amid numerous informal discussions between Centre delegates, technical presentations by researchers and students were given over the course of the following seven sessions:

1. Soil-structure interaction.

2. Submarine landslides/numerical methods.

3. Soft soils.

4. Geomaterials modelling/renewable energy.

5. Pipelines/geomaterials modelling.

6. Centrifuge modelling/soil-structure interaction.

7. Risk, failure, fatigue and tectonics.

UoN UWA UoW IndustryResearch 7 6 3 -

ECRs 3 4 1 -

Student 3 5 - -

Technical 2 - - -

Coffey - - - 2

Douglas - - - 2

Total 15 15 4 4

Above: Jim Hambleton presenting a paper.

Proceedings of the workshop were kept in the form of a printed book of abstracts and an electronic collection of presentation slides.

The number of attendees from each node is outlined below:

Above: RHD students Omid Kardani and Xue Zhang.L-R: Dave White, Richard Merifield, Mark Cassidy, Scott Sloan, Christophe Gaudin and Mehrdad Kimiaei.

CONTRIBUTION TO THE NATIONAL BENEFIT

With a forecast investment of over 250 billion dollars in Australia’s energy and transport infrastructure over the next five years, there is an unprecedented need to design and build this infrastructure as cheaply and safely as possible. In light of the size of the investment involved, even small percentage savings resulting from scientific research will lead to large returns in absolute dollar terms. By combining the strengths of three of Australia’s leading geotechnical research groups, the CGSE will provide engineers with new science-based tools for predicting the safety of offshore and onshore geostructures such as oil and gas platforms, roads, railways, tunnels, dams, and port facilities.


WEBSIT/CONTRIBUTION TO THE NATIONAL BENEFIT

82

WEBSITE

Dom Sammut, Web Developer at The University of Newcastle, designed the CGSE logo and website http://www.newcastle.edu.au/research-centre/cgse/ which went live on 22 November 2011. Since its inception, 120 pages have been viewed a total of 11,872 times, and the site typically attracts around 300 unique visitors per day.

CENTRE PERFORMANCE 30 JUNE 2011 - 31 DECEMBER 2011


CENTRE PERFORMANCE

83


CENTRE PERFORMANCE – STANDARD PERFORMANCE INDICATORS

84

STANDARD PERFORMANCE INDICATORS

KEY RESULT AREA PERFORMANCE MEASURE 2011

TARGET 2011

ACTUAL

Research Findings

Number of research outputs: Journal papers Conference papers

80 (total)

122 84

Quality of research outputs: Ratio of journal to conference papers Percentage of papers in A/A* journals

1:1

75%

1.45:1 79%

Number of invited talks/papers/keynote lectures given at major international meetings

4 13

Number of commentaries about the Centre’s achievements: Media releases Articles

3 2

12 14

Research training and professional

education

Number of attended professional training courses for staff and postgraduate students: Presentations at national and international conferences and workshops Internal training courses

6

4

22

2

Number of Centre attendees at all professional training courses: Presentations at national and international conferences and workshops Internal training courses

15

5

83

12

Number of new postgraduate students working on core Centre research and supervised by Centre staff (including PhD, Masters by research and Masters by Coursework)

5 15


CENTRE PERFORMANCE – STANDARD PERFORMANCE INDICATORS

85

KEY RESULT AREA PERFORMANCE MEASURE 2011

TARGET 2011

ACTUAL

Research training and professional

education

Number of new postdoctoral researchers recruited by the Centre working on core Centre research.

6 9

Number of new Honours students working on core Centre research and supervised by Centre staff: Supervision of final year project students

10

54

Number of Early Career Researchers (within five years of completing PhD) working on core Centre research (cumulative)

6 8

Number of students mentored: Undergraduates Postgraduates

10 5

59 43

Number of mentoring programs: Oral Presentation skills, technical writing skills, grant writing skills

3

20

International, national and

regional links and networks

Number of international visitors and visiting fellows 10 47

Number of national and international workshops held/organised by the Centre 1 1

Number of visits to overseas laboratories and facilities 10 34

End-user links

Number of government, industry and business community briefings 3 14

Number of website hits 200 7,611

Number of public talks given by Centre staff 5 17

Organisational support

Number of new organisations collaborating with, or involved in, the Centre 1 -

Integration of Australian

geotechnical research

Multi-noded authorship of publications 5 7

Multi-noded supervision of PhD Students 1 1


FINANCIAL REPORT

86

FINANCIAL REPORT

FUNDING INCOME

ARC CGSE Grant Income $2,133,075

ARC CGSE ECR Awards $1,242,445

Institutional Cash Contribution $1,025,000

Partner Organisation Funds Coffey Geotechnics $50,000

Partner Organisation Funds Douglas Partners $50,000

Partner Organisation Funds Advanced Geomechanics $50,000

NSW Science Leveraging Fund (SLF) $500,000

Total Funding Income (a) $5,050,520

INCOME DISTRIBUTION BY UNIVERSITY

University of Newcastle $2,610,068

University of Western Australia $1,381,557

University of Wollongong $1,058,895

Total $5,050,520

EXPENDITURE

Salaries $754,307

Scholarships $169,230

Equipment $214,679

Consumables (Maintenance) $131,681

Travel $133,448

Other $91,384

Total Expenditure (b) $1,494,729 Surplus/(Deficit) (a)-(b) $3,555,791 CARRIED FORWARD TO 2012 $3,555,791


FINANCIAL REPORT

87


FINANCIAL REPORT

88

OTHER INCOME

NEWSYD In situ soil testing Bates $208,512 TU Hamburg-Harburg Investigate the tendency for pile plugging during

installation, depending on the installation method and relative sand density

Bienen $23,422

TU Hamburg-Harburg Investigate the tendency for pile displacement accumulation, when subjected to varying cyclic loading.

Bienen $10,000

The Lloyd’s Register Educational Trust (LRET)

Model the geotechnical behaviour of offshore foundations and predicting the risk of their failure

Cassidy $359,302

Institutional Cash Contribution to The LRET

Model the geotechnical behaviour of offshore foundations and predicting the risk of their failure

Cassidy $300,000

WA ERA Marine Geohazards Cassidy $158,735 CLP Power Hong Kong Instrumentation System for Suction Caissons Gaudin $31,000 Industry Component LP0989433

A novel foundation to extend the operation of mobile structures into deeper waters

Gaudin & Cassidy

$27,500

University of Maine Design of mooring systems for floating offshore wind turbines.

Gaudin & Cassidy

$31,750

Inpex Centrifuge modelling of Gas Export Pipeline-soil interaction

Gaudin & White $182,180

Subsea 7 Mudmat Design under general multi-dimensional loading

Gourvenec & Randolph

$22,880

Industry Component LP110100174

Estimation of spudcan penetration resistance in stratified soils directly from field penetrometer data and quantification of punch-through risk.

Hossain, Randolph & Cassidy

$50,480


Cyclic Behaviour of Unstable Soils Stabilised by Lignosulfonate with Special Reference to Rapid Transport Infrastructure

Indraratna $70,000


Geotechnical Properties and Compaction Characteristics of Granular Wastes as Potential Port Reclamation Fill

Indraratna $70,000


Study of Coupled Water-Gas-Sediment (three-phase) Flows through Jointed and Stratified Rock

Indraratna $25,000


Advancement of Vacuum Pressure Application via Prefabricated Vertical Drains for Stabilising Soft Ground

Indraratna $75,000

Institutional Cash Contribution Laureate Fellowship

Failure Analysis of Geotechnical Infrastructure Sloan $300,000

Atkins Boreas Axial and lateral pipe-soil interaction within the SAFEBUCK GEO JIP

White $88,985

BP Centrifuge modelling of pipe-soil interaction White & Gaudin $331,325 Woodside Centrifuge modelling of lateral pipe-soil interaction White & Gaudin $331,250

Total Other Income (d) $2,697,321

TOTAL OTHER INCOME (c)+(d) $4,860,841

TOTAL INCOME FROM ALL SOURCES (a)+(c)+(d) $9,911,361


FINANCIAL REPORT

89

IN KIND SUPPORT

In Kind Support University $1,096,623

In Kind Support Partner Organisations $128,800

n Kind Support Colorado School of Mines $18,388

In Kind Support Local Government (Ballina Bypass) $5,000

Total In Kind Support $1,248,811


FINANCIAL REPORT

90


FINANCIAL STATEMENT

91

FINANCIAL STATEMENT

1 of 2

Research Project: Centre of Excellence for Geotechnical Science and EngineeringProject ID: CE110001009Director: Laureate Professor Scott SloanAdministering Institution: University of Newcastle

University of Newcastle

University of Western Australia

University of Wollongong

Sub Total Total

INCOME:

Bal Brought Fwd - ARC CoE Income 2011 1,039,874 906,557 186,644 2,133,075 2,133,075 Bal Brought FwdARC CoE DECRA Income 2011 570,194 - 672,251 1,242,445 1,242,445 Bal Brought FwdCash Contributions 2011 500,000 425,000 100,000 1,025,000 1,025,000 Bal Brought FwdIndustry Partner Contributions 100,000 50,000 150,000 150,000 Bal Brought FwdNSW Science Leverage Fund (SLF) 400,000 - 100,000 500,000 500,000

Total Available ARC CoE GSE Available Funds: 2,610,068 1,381,557 1,058,895 5,050,520 5,050,520

EXPENDITURE:

Salaries 362,384 297,180 94,743 754,307

Scholarships - 169,230 - 169,230

Equipment 181,533 33,146 - 214,679

Consumables (Maintenance) 131,681 - - 131,681

Travel 28,747 104,588 113 133,448

Other - 91,384 - 91,384

Total of All Institution's Expenditure 2011: 704,345 695,528 94,856 1,494,729 1,494,729

Surplus/(Deficit) 1,905,723 686,029 964,039 3,555,791 3,555,791

ARC Centre of Excellence for Geotechnical Science and Engineering (GSE)

2011 Financial Statement


FINANCIAL STATEMENT

92 2 of 2

Research Project: Centre of Excellence for Geotechnical Science and EngineeringProject ID: CE110001009Director: Laureate Professor Scott SloanAdministering Institution: University of Newcastle

University of Newcastle

University of Western Australia

University of Wollongong

Sub Total Total

ARC Centre of Excellence for Geotechnical Science and Engineering (GSE)

2011 Financial Statement

SUMMARY AND RECONCILIATION:Total ARC CoE Funds Provided to GSE 2011 1,039,874 906,557 186,644 2,133,075 Less: GSE Expenditure applied to ARC funds 2011 (197,729) (695,528) (94,856) (988,114)

Net ARC CoE GSE 842,145 211,029 91,788 1,144,961 1,144,961 Total ARC CoE DECRA Funds Provided to GSE 2011 570,194 - 672,251 1,242,445 Less: GSE DECRA Expenditure applied to ARC funds 2011 (6,615) - - (6,615)

Net ARC CoE GSE DECRA 563,578 - 672,251 1,235,829 1,235,829

TOTAL ARC Funds to be Carried Forward 2,380,791

Cash Contributions 2011 500,000 425,000 100,000 1,025,000 Less: GSE Expenditure 2011 Charged to Cash Contributions (500,000) - - (500,000)

Net Cash Contributions - 425,000 100,000 525,000 525,000

Industry Contributions 2011 100,000 50,000 - 150,000 Less GSE Expenditure 2011 Charged to Industry Contributions - - - -

Net Industry Contributions 100,000 50,000 - 150,000 150,000

NSW SLF Contributions 2011 400,000 - 100,000 500,000 Less GSE Expenditure 2011 Charged to NSW SLF Contributions - - - -

Net NSW SLF Contributions 400,000 - 100,000 500,000 500,000

TOTAL NON ARC Funds to be Carried Forward 1,175,000

ARC CoE GSE NET POSITION TO CARRY FORWARD INTO 2012 3,555,791

Damien RyanSenior Research AccountantThe University of NewcastleDate: 27/03/12

This special purpose financial statement combines the financial statements for the ARC Centre of Excellence for Geotechnical Science and Engineering (GSE) from the three collaborative Universities named above. The financial statements provided by the University of Wollongong and the University of Western Australia have both been signed off by their relevant finance department representatives in addition to their collaborative chief investigator in assurance of the financial information provided.

The financial information provided by the University of Newcastle is a complete extract from the cost collectors created for GSE within the University's ledger. These transactions have been accounted for in accordance with applicable Australian Accounting Standards with the exception of capital purchases which are expensed for the purposes of acquitting ARC funds.

All collaborative GSE University partners have thier annual financial report audited by their respective State Auditor General on a calendar year basis.

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