subsea pipelines collaboration cluster

Advancing our knowledge of subsea pipeline technology to support the oil and gas industry

Subsea Pipelines Collaboration ClusterFinal report

wealth From oCeanSwww.csiro.au

2 Executive summary

4 Introduction to the Subsea Pipelines Cluster

6 Training the offshore pipeline engineers of the future

10 Scientific and engineering challenges

12 Scientific outcomes of the Flagship Collaborative Cluster

17 Putting the Cluster’s research into practice

21 Commissioning experimental equipment for ongoing pipeline testing in Australia

28 Publications and dissemination

34 Key papers

46 Awards

48 Keynote presentations, invited lectures and papers

49 Hosting international conference ISFOG

50 The Partners

51 Flagship Collaboration fund

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2 Subsea Pipeline Collaboration Cluster – final report

Executive summaryOffshore subsea pipelines are used to export oil and gas from the field to platform and then from the platform to the mainland. As they are the sole conduit for the hydrocarbons their stability and integrity are of critical economic and environmental importance.

More than 80 per cent of Australia’s gas resources exist in deep, remote, offshore areas and being able to realise the full potential of these remote resources relies on the development of economically viable transportation solutions. Technical solutions for Australia’s offshore pipelines must maintain structural integrity and continuous supply of products across hundreds of kilometres of seabed.

Such technology is also vital to Australia achieving the vision of “platform free fields”, a CSIRO Wealth from Oceans Flagship initiative. Platform free fields research investigates ways to replace traditional oil and gas platforms with subsea technologies for production of gas resources which may lie as far as 300 km offshore, at a depth greater than 1 km.

To address the challenges of providing technical solutions to the Australian oil and gas industry, six universities and CSIRO’s Wealth from Ocean Flagship came together in 2008 to establish the Subsea Pipelines Collaboration Cluster. Its goal was to underpin the development of these hydrocarbon resources, by providing engineering solutions for the safe and economic design and operation of subsea pipelines in Australia’s offshore frontiers. This research Cluster was enabled by a $3.6 million grant through the CSIRO Flagship Collaboration Fund and in-kind contributions from the participating universities of $7.4 million. Bringing together an integrated and multi-disciplinary team has been fundamental to the success of the Cluster.

The Cluster has resulted in significant advances in the understanding of subsea pipeline technology,

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including the development of state-of-the-art experimental equipment to test pipeline attributes.

Key achievements include establishing new numerical models and software for analysing the stability of offshore pipelines, novel methodologies for economic and safe pipeline design, and the commissioning of world-class experimental and pipeline testing facilities. These have resulted in specialist testing and consultancy services being available to the offshore pipeline industry. The increased knowledge and understanding will contribute to CSIRO’s own research in the areas of gas flow assurance and production. They are also publically available with the Cluster having published more than 160 manuscripts in international journal and conference proceedings.

Results from the Cluster’s research has already been incorporated into the next generation of subsea natural gas projects such as the A$43 billion Gorgon project in north-west Western Australia that involves the development of the Greater Gorgon gas fields and a LNG plant on Barrow Island, near Karratha. Acting for clients BP, Chevron, Inpex and Woodside, testing facilities developed have also underpinned designs for Australia’s future pipelines to the Pluto, Wheatstone, Ichthys and Browse fields (off the north-west Western Australian coast) and in international projects offshore West Africa, Egypt and in the Caspian sea. Research in the cluster also formed part of a joint industry project sponsored by the six energy majors BHP Billiton Petroleum, BP, Chevron, Petrobras, Shell and Woodside, and administered by the Minerals and Energy Research Institute of Western Australia (MERIWA Project M395).

The current boom in Australian oil and gas has caused a skills shortage in key engineering fields. It is therefore a key achievement that this cluster has also trained 41 offshore engineers and researchers for the benefit of the offshore oil and gas industry through its PhD and postdoctoral programs. This will help underpin the future success of engineering in this area of national priority.

The Cluster outcomes are helping to build future research priorities in CSIRO, the Universities and with industry partners in the areas of pipeline design and installation in Australian calcareous soil conditions and in deep water, geohazard risk assessment, use of automated underwater vehicles and in developing the vision of platform free fields in Australia. Future activities, such as interactive workshops, will build on this successful collaborative relationship.

This report summarises the achievements of the Subsea Pipeline Collaboration Cluster and its impact on the Australian and international oil and gas industries.

Past CSiro wealth of oceans Flagship Director Kate wilson (right), CSiro energy executive Bev ronalds (centre) and uwa Vice Chancellor alan robson (left) at the Cluster launch

mark Cassidy

Leader

CSIRO Flagship Collaboration Cluster on Subsea Pipelines

The University of Western Australia

ian Cresswell

Acting Director

CSIRO Wealth from Oceans Flagship


Introduction to the Subsea Pipelines ClusterBuilding a pipeline system to link an offshore oil and gas field to the mainland represents a huge capital investment. For example, in Australia the construction of the 42 inch 135 km pipeline for the Trunkline System Expansion Project (TSEP) on the North West Shelf in 2003/04 cost approximately A$800 million. Today, the cost per kilometre of current pipeline projects, including the Gorgon (water depth: 1350 m length: 65 and 140 km), Scarborough (depth: 900m length: 280km), Pluto (depth: 830m length: 180km) and Browse (depth: 600m length: 5, 24 and 400km) is estimated to exceed $4.5 million per kilometre. With over 2000km of pipelines under design in Australia, capital expenditure is expected to exceed $10 billion.

With more than 80 per cent of Australia’s gas resources exist in deep, remote, offshore areas, our ability to realise their full potential relies on the development of economically viable solutions to transport them.

Such technology is vital to Australia achieving the vision of Platform Free Fields, a CSIRO Wealth from Oceans Flagship program. This research investigates ways to replace traditional oil and gas platforms with subsea technologies for production of gas

resources which are considered stranded off our coast in deep water and at long distances to land. Under these conditions subsea pipelines are required to transport the gas over long distances to shore. Transporting hydrocarbons in extra long offshore pipelines poses many challenges that must be considered when designing pipelines. These include stability of pipeline structures over decades in strong currents, a shifting seabed and on steep seabed slopes. Assessment and mitigation of potential geohazards, such as submarine landslides, is also critical for the safe routing of pipelines.

The Subsea Pipelines Collaboration Cluster was established to meet these challenges and to deliver science-based engineering solutions for the safe and economic design and operation of subsea pipelines in Australia’s deepwater frontiers. Research has focused on ultralong pipelines from deepwater to shore, a critical goal of Platform Free Fields.

The CSIRO Flagship Collaboration Fund enables the skills of the wider Australian research community to be applied to the major national challenges targeted by CSIRO’s National Research Flagship Program. As part of the $480 million provided over seven years by the Australian Government to the National Research Flagships, $115 million was allocated specifically to enhance collaboration between

CSIRO, Australian universities and other publicly funded research agencies.

The Subsea Pipeline Collaboration Cluster was initiated by the Wealth from Oceans Flagship to bring together a diverse range of research capabilities to deliver an in-depth scientific understanding of the key parameters involved in subsea pipeline design, construction, long-term operation and monitoring.

The three year program contributed to CSIRO’s research program that aims to work with industry to develop the science and technology to unlock new opportunities in the exploration and development of Australia’s offshore hydrocarbon resources. The $7.4 million Cluster included $3.6 million from the Flagship Collaboration Fund and $3.8 million in-kind contributions from the participating universities.

The Subsea Pipeline Collaboration Cluster combined the research capabilities of The University of Western Australia, Curtin University of Technology, The University of Queensland, Monash University, The University of Sydney, Flinders University and CSIRO through the Wealth from Oceans National Research Flagship. From a start of 17 Chief Investigators the cluster grew to eventually encompass 31 academic researchers and another 27 PhD and Masters students.

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CSIRO Cluster on Subsea Pipelines Participants

SEABED CHARACTERISATIONlead researcherProfessor Mark Randolph

researchersProfessor Liang ChengProfessor David WhiteProfessor Mark CassidyDr Itai EinavDr Pierre RognonDr Noel BoylanDr Hongxia Zhu

PhD StudentsHan Eng LowZhihui YeYan YueHamed Mahmoodzadeh Poornaki

STRUCTURAL INTEGRITYlead researcherProfessor Mark Cassidy

researchersProfessor Xiao-Ling ZhaoProfessor Jayantha KodikaraDr Faris AlbermaniDr Yinghui TianProfessor Mark RandolphProfessor David WhiteDr HongBo LiuDr Zhigang Xiao (until 2009)Dr Pathmanathan Rajeev

PhD StudentsMehdi GolbaharMatthew HodderBassem YoussefSenthilkumar MuthukrishnanHossein Khalilpasha

SEABED MORPHOLOGYlead researcher Professor Liang Cheng

researchersDr Ming ZhaoDr Zhipeng Zang

PhD StudentsDi WuSiti Fatin Mohd RazaliFang Zhou (Visitor)Xiaosong Zhu (Visitor)

PIPELINE HAZARDS lead researcher Professor David White

researchers Professor Liang ChengProfessor Mark Randolph Associate Professor Yuxia HuDr Tom BaldockDr Christophe GaudinDr Nathalie BoukpetiDr Dong WangDr Noel Boylan

PhD StudentsJaya Kumar SeelamHee MinIndranil GuhaFauzan Sahdi

PIPELINE RELIABILITYlead researcherProfessor Hong Hao

researcherProfessor Mark Cassidy Dr Ying Wang

PhD StudentsXuelin PengChunxiao BaoWang Chao (Visitor)

AUV AND ROV-BASED SYSTEMS FOR PIPELINE MONITORINGlead researcherAssociate Professor Karl Sammut

researchersAssociate Professor Fangpo HeDr Jimmy LiDr Kim KlakaDr Alec DuncanMr Andrew Woods

PhD StudentsAndrew LammasMatthew KokegeiDavid RobertTae-hwan JoungLyndon WhaiteGrant Pusey


Training the offshore pipeline engineers of the futureThe Subsea Pipeline Collaboration Cluster is not only devising tomorrow’s subsea pipeline technology, it is providing significant research training for Australia’s future pipeline engineers. In all, 27 PhD students and 14 research associates undertook pipeline research within the cluster.

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Chief Investigators

Jayantha Kodikara

Xiao-Ling Zhao

Itai Einav Faris Albermani

Tom Baldock

Jimmy Li

Kim Klaka

Alec Duncan

Andrew Woods

Mark Cassidy

the university of western australia the university of Sydney

Flinders university

Curtin university of technology

monash university

the university of Queensland

Mark Randolph Liang Cheng

David White

Hong Hao

Karl Sammut

Christophe Gaudin

Fangpo He


CSIRO Cluster Postdoctoral Research AssociatesNAME INSTITUTION PROjECT WHERE THEY ARE NOW?

Hongjie Zhou University of Western Australia Seabed Characterisation Advanced Geomechanics

Pierre Rognon University of Sydney Seabed Characterisation University of Sydney

Noel Boylan University of Western Australia Seabed Characterisation Pipeline Hazards

Advanced Geomechanics

Yinghui Tian University of Western Australia Structural Integrity University of Western Australia

Zhigang Xiao Monash Structural Integrity Monash University

Pathmanathan Rajeev Monash Structural Integrity Monash University

HongBo Liu Monash Seabed Integrity Monash University

Ming Zhao University of Western Australia Seabed Morphology University of Western Sydney

Zhipeng Zang University of Western Australia Seabed Morphology

Nathalie Boukpeti University of Western Australia Pipeline Hazards University of Western Australia

Dong Wang University of Western Australia Pipeline Hazards University of Western Australia

James Schneider University of Western Australia Pipeline Hazards University of Wisconsin-Madison

Ying Wang University of Western Australia Pipeline Reliability Shanghai Jiao Tong University

Andrew Lammas Flinders Pipeline Monitoring Flinders University

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CSIRO Cluster Postgraduate Student ParticipantsNAME INST. THESIS TITLE CLUSTER STREAM

Name Inst. Thesis Title Cluster Stream

James Schneider UWA Analysis of piezocone data for displacement pile design Pipeline Hazards

Hongije Zhou UWA Numerical study of geotechnical penetration problems for offshore applications

Seabed Characterisation

Han Eng Low UWA Performance of penetrometers in deepwater soft soil characterisation Seabed Characterisation

Matthew Hodder UWA Geotechnical analysis of offshore pipelines and steel catenary risers Structural Integrity

Di Wu UWA Experimental and numerical modelling of natural backfill of navigation channels and pipeline trenches

Seabed Morphology

Grant Pusey Curtin Characterisation of long-range horizontal performance of underwater acoustic communication

Pipeline Monitoring

Siti Fatin Mohd Razali UWA Wake characteristics of yawed circular cylinders and suppression of vortex-induced vibration using helical strakes

Seabed Morphology

Xuelin Peng UWA Condition monitoring of offshore pipelines using vibration based method Pipeline Monitoring

Jaya Kumar Seelam UQ Tsunami induced bed shear stresses- project 4 Pipeline Hazards

Benham Shabani UQ Ben contributing to the modelling of Jaya's but PhD otherwise unrelated Pipeline Hazards

Andrew Lammas Flinders 6 Degree of Freedom Navigation Systems for Autonomous Underwater Vehicles

Pipeline Monitoring

Matthew Kokegei Flinders Fully Coupled 6 Degree of Freedom Control Systems for Autonomous Underwater Vehicles

Pipeline Monitoring

Yan Yue UWA Novel methods for characterising pipe-soil interaction forces in-situ in deep water

Seabed characterisation

Bassem Youssef UWA Use of probability models in the integrated analysis in offshore pipelines Structural Integrity

Zhihui Ye UWA Erosion threshold and erosion rate of seabed sediments Seabed Characterisation

Santiram Chatterjee UWA Modelling of pipeline seabed interactions Seabed Characterisation

David Roberts Flinders Pipeline Tracking Using Scanning Sonar Imaging Pipeline Monitoring

Tae-hwan Joung Flinders Computational Fluid Dynamics Modelling Techniques for Analysing the Performance of a AUV Thruster

Pipeline Monitoring

Lyndon Whaite Flinders Mesh Free Methods for Probabilistic Optimal Control and Estimation of Autonomous Underwater Vehicles

Pipeline Monitoring

Fauzan Sahdi UWA Modelling of submarine slides and their impact on pipelines Pipeline Hazards

Amin Rismanchian UWA Three dimensional modelling of pipeline buckling on soft clay Seabed Characterisation

Senthilkumar Muthukrishnan

Monash Offshore pipe clay seabed interaction in axial direction Structural Integrity

Chunxiao Bao UWA Vibration based structural health monitoring of onshore and offshore structures

Pipeline Reliability

Indranil Guha UWA Structural analysis of submarine pipelines under submarine slide and thermal loading

Pipeline Hazards

Hossein Khalilpasha UQ Propagation buckling of deep subsea pipelines Structural Integrity

Hamed Mahmoodzadeh Poornaki

UWA Interpretation of partially drained penetrometer tests with applications to the design of spudcan foundation

Seabed Characterisation

Hassan Karampour UQ Coupled upheaval/lateral and propagation buckling of ultra-deep pipelines Structural Integrity


Scientific and engineering challengesThe Subsea Pipeline Collaboration Cluster investigated and developed scientific solutions to overcome the challenges of constructing pipelines from oil and gas reserves in water depths exceeding 1000 metres.

For safe and economic developments such pipelines are required to maintain their structural integrity and continuously supply hydrocarbons across hundreds of kilometres of rugged, often shifting, seabed to bring the hydrocarbons to shore.

The Cluster brought together a diverse range of research capabilities to deliver an in-depth scientific understanding of subsea pipelines in the areas of:

◆ design

◆ construction

◆ long-term operation

◆ real-time monitoring.

The aim of the program was to provide a technical basis for the design of pipelines for any new offshore field, which contrasts with the current case-by-case approach, significantly reducing costs and uncertainties

for future pipeline design projects, with particular relevance to remote offshore locations around Australia.

There were six research streams which mimicked the life cycle of a pipeline, from characterising the design environment to monitoring any risk of failure during operation.

These streams were:

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Sea-bed amplitude map showing features of the Gorgon slide, north west Shelf

Full-life reliability This research assessed the feasibility of using vibration measurement to monitor the health of pipelines, with the aim of replacing expensive and irregular visual monitoring with continuous measurements and analysis. Both numerical simulation and experimental test results indicate that vibration measurement is very sensitive to pipeline scouring damage. Methods were developed for possible applications to monitor pipeline conditions online.

Pipeline monitoringResearch explored the use of autonomous underwater vehicles (AUVs) for continuous monitoring, assessment of pipeline integrity and evaluation of the seafloor, and the autonomous operation of an underwater communication link between acoustic modems. The scope of the AUV work included developing new navigation, control, and guidance techniques. These new techniques aimed to improve a vehicle’s capability to move more accurately over long distances while working close to objects; to detect and track pipelines; and to manoeuvre to deploy instruments into the seabed.

The technical detail and major outcomes will now be presented for each of these research streams.

Seabed characterisation This project concentrated on advanced testing of seabed sediment characteristics to understand how they may affect pipelines resting on the seabed. Current methods practised in industry are hampered by the expense of having to conduct multiple tests along a long pipe route, inaccuracies in interpreting site-characterisation tools developed for traditional deep foundation rather than the top 1 m layer of soil, and difficulties of collecting soil samples for onshore laboratory testing. Novel equipment and interpretative methods were developed to define the main engineering parameters required for pipeline design, such as seabed strength and the effects of seabed erosion. These included the piezoball, toroidal and hemispherical shallow ball penetrometers.

uwa miniature piezoball

Seabed morphologyResearch was conducted into the formation mechanisms of seabed sand waves and in developing a model to predict the evolution of sand waves with and without the presence of a pipeline. The project developed methods to predict the three-dimensional erosion of the seabed under pipelines.

Pipeline stability studies in the miniature o-tube

Structural integrity This project developed new numerical models and design frameworks for the analysis of pipeline stability and fatigue by integrating the interactions and effects of the seabed, currents and waves on the pipeline structure.

Pipeline hazards Deep-water developments require pipeline routing up the continental slope in areas of changing seabed morphology and other geohazards. One key technical challenge addressed by the Cluster was the impact of a submarine landslide sliding down the continental slope and colliding with a pipeline. Based on physical and numerical modelling, this research developed new calculation methods and analysis tools. These tools were used to model the run-out of submarine slides and to assess their consequent impact forces and potential damage to submarine pipelines, together with an assessment of tsunami-induced bed shear stresses and pressure gradients on the sea floor.


Scientific outcomes The following are the major scientific outcomes of the Subsea Pipeline Collaboration Cluster

◆ Development of novel penetrometers and techniques for interpreting soil properties, including an enhanced ball-shaped penetrometer – the piezoball – and new toroidal and hemispherical devices for deployment at the seabed. These devices are already being used in practical applications offshore, where they are deriving soil properties in the upper metre of soil, the most relevant part of the seabed for pipeline design.

◆ Development of a methodology for interpreting pipeline axial friction design values from novel toroidal and hemispherical penetrometer results.

miniature piezoball in beam centrifuge

◆ Complementary geotechnical centrifuge and field testing of the piezoball penetrometer at UWA, the Riverside site in East Perth and the Kvenild and Dragvoll sites in Norway (the latter in collaboration with the Norwegian University of Science and Technology). The tests examined the transition between intact and remoulded shear strength, as well as dissipation tests to examine the consolidation properties of the soil. Both are essential in the interpretation of seabed properties for design of deepwater pipelines.

◆ Proposed interpretative method for adjusting measured piezoball resistance to allow for the effects of partial consolidation.

◆ Established new solutions for the interactive forces between pipelines and the seabed during axial and lateral movement, on both coarse-grained and fine-grained seabeds, with these solutions being encapsulated into an efficient macroelement framework.

Distribution of excess pore pressure after a 3-diameter penetration

Piezoball testing in trondheim – (from left) noel Boylan (formerly CoFS), mike long (uCD), annika Bihs (ntnu), Jan Jønland (ntnu) and roselyn Carroll (uCD)

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Profiles of (a) u2 and umball (b) Bq and Bmball

Softening factor1.000.950.900.850.800.750.710.660.610.560.510.460.140.360.31

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◆ Established framework for incorporating macroelement pipe-seabed models into structural analysis programs, including uplift and reattachment.

◆ Extension of plasticity models describing the pipe-soil load displacement behaviour on Australia’s calcareous sands to lateral displacements of up to five diameters.

◆ Development of numerical analysis code for integrated storm loading on on-bottom pipelines.

◆ Proposed formulae to calculate the natural frequency of free spanning subsea pipelines by considering the boundary conditions, mass of hydrocarbon products, axial force and multiple spans.

◆ Development of numerical analysis using boundary element method to predict the fatigue life of subsea pipelines subject to combined actions.

◆ Development of a numerical model that simulates sand wave formation and evolution.

◆ Verification of the Regional Oceanographic Modelling System (ROMS) model for sand wave migration and sand wave-pipeline interaction model against offshore data and comparison of numerical results to other published models.

◆ Establishment of a numerical model for three-dimensional flow and scour under pipelines, and subsequent validation of the model against experiments.

◆ Analysis of initial embedment and subsequent axial displacement coupling pore pressure dissipation and soil deformation.

◆ Analysis of the influence of boundary conditions, hydrocarbon products and axial pipeline tension on the natural frequency of on-bottom pipelines.

◆ New convolution models to calculate total bed shear stresses for solitary waves and breaking tsunami wave fronts.

◆ Establishment of state-of-the-art experimental equipment for ongoing testing to support the design of Australia’s offshore pipelines, including:

– the world’s first facility for simulating submarine slides at small scale within a geotechnical drum centrifuge

– a pressurised testing vessel of 4m length and 173mm internal diameter that is rated for 20MPa and capable of simulating the propagation of pipeline buckling during deep water installation and operation (up to 2000m water depth)

(a) (b)

example of video footage images of (a) a pipeline crossing a sleeper and (b) an as-laid survey in silt

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– an experimental testing rig for studying general and field specific cyclic axial interaction behaviour between the pipe and soil behaviour for general loading under drained or undrained conditions

– a mini O-tube facility for testing of soil erosion properties and small scale modelling of seabed-infrastructure-ocean interaction, allowing observations of the flow conditions and measurement of the erosion threshold of seabed sediments

– establishment of laboratory testing apparatus to measure bed shear stress under tsunami-shaped waves

– development of capabilities for simulating whole-life loading histories on model pipes in the geotechnical centrifuge, including storm-induced hydrodynamic load sequences, and thermally-induced lateral buckling cycles

– development of miniaturised versions of new field-scale penetrometers, to allow comparative testing of reconstituted and in situ seabed sediments, in support of centrifuge model testing.

◆ Validation of vibration-based methods to reliably monitor the condition of subsea pipelines (though their practical implementation still depends on a number of issues including the ability to transmit the vibration data and power the sensors).

◆ For the application of autonomous underwater vehicles, the project developed:

– a new full-order particle filter based navigation algorithm that can estimate an autonomous underwater vehicle’s position,

attitude, velocity, and rotational rates, as well as water currents acting on the vehicle

– a fully-coupled control algorithm to achieve improved manoeuvring close to hazards and reduce battery consumption

– a pipeline tracking system that can detect and track multiple pipelines

– hardware and software modules that embed these navigation, control and guidance system in an AUV.

◆ Development of hardware and software for controlling and monitoring the performance of underwater acoustic modems, while simultaneously recording the ambient noise and modem transmissions on a wide-bandwidth recorder.

◆ Underwater acoustic modems evaluated for their capacity to transmit data along a pipeline. Long-term, 16-day trials of a five-kilometre communication link between two seabed-mounted modems in 100m allowed detailed comparisons to be made between measured modem performance and performance predicted by numerical simulators.

mini o-tube facility

Putting the Cluster’s research into practiceThe Collaboration Cluster’s work has revolutionised subsea pipeline technology and its findings have already been implemented in oil and gas projects off Australia and elsewhere in the world.

Meanwhile, four other long-distance pipelines – Gorgon, Wheatstone, Ichthys and Browse – are at an advanced stage of design, and many shorter pipelines are being designed. These new pipelines are technically very challenging: some will extend into deeper waters, well beyond the shelf break, and some – notably those to the Ichthys and Browse fields – will be located north of Broome, in different oceanographic and geotechnical conditions compared to the existing experience in the Carnarvon basin.

The new challenges of new regions, greater pipeline lengths, deeper water and new geohazards, have all been tackled within the Cluster, and the research techniques and outcomes spearheaded by the Cluster have already been applied to the design of Australia’s new pipelines.

These same technologies have also been applied to projects elsewhere in the world, such as for BP’s PSVM field off Angola, West Nile Delta offshore Egypt and Shah Deniz in the Caspian Sea. This is recognising Australia’s technical leadership in pipeline engineering and the pivotal role this Cluster has played in developing testing facilities and design practises.

The Cluster’s research programs resulted in several industry advances such as:

◆ improved site characterisation through new technologies

◆ specialised geotechnical centrifuge testing

◆ advanced numerical modelling

◆ cyclone simulation experiments in the newly established O-Tube facility.

Also, through a joint industry project involving six offshore operators (BHP Billiton Petroleum, BP, Chevron, Petrobras, Shell and Woodside), new approaches for geohazard assessment have been derived and applied in projects, including the A$43billion Gorgon project in north-west Western Australia that involves designing a pipeline to travel from 1350m water depth at the Greater Gorgon gas fields to the LNG plant on Barrow Island, near Karratha.

Key aspects of the Cluster’s innovative contributions to pipeline technology include

Industry Impact through Geotechnical Centrifuge Testing

Two critical components of pipeline design are the assessment of on-bottom stability under severe hydrodynamic loading – from storms or tides – and the overall response of the pipeline to internal temperature and pressure. Under both conditions, the pipe may be permitted to move significant distances back and forth across the seabed, but these movements must not be excessive and the pipe must not be over-strained.

A critical input to assessment of pipeline stability under these movements is the interaction forces between the pipe and the seabed. Centrifuge model testing, using offshore soil samples and accurate simulation of the pipeline weight and movements, provides observations that can be used to refine and validate

models for pipe-soil interaction, leading to reduced design uncertainty. New experimental techniques were developed at UWA during the Cluster project, and these have resulted in more realistic simulations of pipeline behaviour. Using these techniques, centrifuge testing has been performed over the past four years, using natural soil samples gathered from offshore and providing results that have had direct impact the design of offshore field pipelines. The specific projects, operators and pipe details are provided in the table on following page.

existing pipeline

Proposed pipelineIchthys

Browse

Gorgon

Wheatstone

industry collaborator Paul Brunning of acergy presenting at the 2009 CSiro Flagship Cluster on Pipelines workshop

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OPERATOR PROjECT YEAR PIPELINE LENGTH MAIN TESTING FOCUS

Woodside Pluto 2007 200km Lateral buckling

BP PSVM 2008 170km Lateral buckling

Chevron Gorgon 2008 65km & 150km As-laid embedment

Chevron Gorgon 2009 150km Storm stability

Chevron Gorgon 2009 150km Free span stability

Chevron Wheatstone 2010 225km Buckling, storm stability

BP B31SE 2010 50km Lateral buckling

Inpex Ichthys (infield) 2010 50km Lateral buckling

Woodside Browse 2011 400km Buckling, storm stability

Inpex Ichthys (export) 2011 850km Lateral buckling

BP West Nile Delta 2011 100km Lateral buckling

BP Shah Deniz 2011 25km Lateral buckling

Summary of centrifuge tests conducted for industry during the Cluster

Berms of soil along pipe in a industry test

These centrifuge studies used new modelling technology that permits arbitrary patterns of load and displacement to be imposed on a model pipeline. This allowed the effects of dynamic laying, thermal start-up and shutdown cycles and hydrodynamic storm loading to be simulated. In some cases, stochastic storm simulations to assess the pipe-soil response during 1000-year and 10000-year return period design events were devised. The underlying technology is described later in this report (also refer to centrifuge modelling technology section).

Industry impact through numerical modelling

Numerical pipe-soil models were incorporated into the industry stability analysis package ABAQUS/SimStab for use in the Gorgon Upstream Joint Venture (GUJV) project. Cluster researchers collaborated with GUJV engineers in initially running the plasticity UWAPIPE models under Gorgon storm conditions, before incorporating the models into the SimStab software for GUJV engineers to use. The new soil models are now being used in the stability analysis of the Gorgon pipeline on the North West Shelf of Australia.

New methods to predict submarine slide-pipelineinteraction

Research into the interaction between submarine slides and pipelines formed a major theme within the cluster, and also a joint industry project administered by the Minerals and Energy Research Institute of Western Australia (MERIWA Project M395) and sponsored by the six energy majors BHP Billiton Petroleum, BP, Chevron, Petrobras, Shell and Woodside. Annual workshops between the sponsoring

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Developing slide experiments at the uwa drum centrifuge

Slide run-out from centrifuge test with compression ridges highlighted

Velocity distributions on deformed softening material

companies and researchers were held in Perth and in Houston, USA.

This project aimed to develop new techniques to characterise and model the geotechnical aspects of submarine slide behaviour. The project encompassed both physical modelling and numerical modelling. A program of novel centrifuge model tests generated a library of well-characterised submarine slides, as well as a database of slide-pipe interaction force measurements. These results were used to validate numerical run-out computations that were performed

using two levels of sophistication – a new, and more refined, implementation of the industry-standard depth-averaged approach, and a continuum-based large deformation finite element method.

The techniques emerging from this research into the assessment of pipeline-slide loading have been applied to the Greater Gorgon development, offshore Australia.

A further significant part of the project was the development of a new geotechnically-based framework to characterise the strength of soft seabed deposits, based on extensive laboratory measurements using different soil types. This framework spans the solid-fluid boundary that is crossed within the slide material as it evolves into a debris flow and, ultimately, a turbidity current. In addition, extensive analytical studies were performed to support the development of new models for the interaction forces between slides and pipelines, and these were distilled into simple design recommendations.

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Commissioning experimental equipment for ongoing pipeline testing in AustraliaMajor equipment development:

Piezoball penetrometers are now used routinely by the Australian site investigation company, Benthic Geotech, in its portable remotely operated drill (PROD). Extensive data were obtained in 2010 for Woodside’s Browse project on the North-West Shelf. ROV-mounted penetrometer capabilities have been developed by companies such as Perry Slingsby in the USA (the Rovdrill) and Geomarine in the UK. Piezoball tests carried out in the project have also given an insight into the interpretation of data in silty carbonate sediments found offshore Australia.

For pipeline design, an important parameter is the axial friction between

pipe and soil. New devices have been developed during the project to target this parameter, by applying torsional loading to a toroidal penetrometer, or to an alternative hemi-spherical penetrometer. In both cases, the torsional interface response between the device and soil represents a close analogue of the axial sliding resistance of a pipeline. Test data at model scale, supported by numerical analysis, have quantified the relationships between axial friction and both the elapsed time and velocity of shearing. Analytical solutions have also been developed that capture these contributions for different soil types, thus providing a method for interpreting data from the equipment.

t-bar penetrometers test on remoulded sample of carbonate silt

Penetrometers for pipeline site investigationThe offshore industry has already made significant advances in site investigation techniques, incorporating full-flow penetrometers such as the T-bar and piezoball devices originally developed at UWA.


These include:

◆ An improved motion control system enabling the modelling of pipeline dynamic installation with complex horizontal and vertical motion interaction and the modelling of pipeline buckling (Figure b) up to 600 cycles. This is a major improvement compared to the previous modelling capability (limited to about 100 cycles), which revealed specific features of pipe soil interaction related to the development of berms and pipe embedment over a large number of cycles.

◆ The establishment of a new driving system for the tool table of the drum centrifuge and a new experimental pipe apparatus. This upgrade was triggered by the necessity to allow a buried model pipeline to be translated

at various velocities through a soil sample contained within the drum centrifuge channel, simulating a pipe engulfed within a submarine slide. By using a soil sample which was initially unconsolidated, the model pipe tests were performed after different degrees of consolidation leading to varying sample properties (density ρ and undrained shear strength su). Pipe translation tests were performed using different model pipes with varying length to diameter ratios in order to determine the optimum pipe geometry that would minimise potential end effects. Once the test technique was established the main program of testing was undertaken. This involved a total of 37 model pipe translation tests spanning a wide range of velocities and soil strengths.

◆ The establishment of optic fibre data transmission on both the beam and the drum centrifuge improving the transfer rate, increasing the quality of the experimental data and enabling high definition videos to taken during experiments.

Horizontal displacement direction

model pipeline during horizontal buckling Buried model pipeline translated through clay of various strengths

Christophe Gaudin and Yinghui tian with the beam centrifuge

UWA’s geotechnical centrifugesBoth the beam (Figure a) and the drum centrifuges at the Centre for Offshore Foundation Systems have had continuous technical upgrades to face the challenges associated with the buckling of pipelines and the impact of submarine slides on pipelines.

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The mini O-tube was formulated as part the Collaboration Cluster and highlighted the feasibility of the experimental testing approach. A larger O-tube was then subsequently funded by UWA, the Australian Research Council, and Woodside and Chevron, via the STABLEPIPE Joint Industry Project.

The facility allows a full ocean-pipeline-seabed interaction to be simulated at large scale. Cyclonic wave and current conditions can be created in the 1.5 m high test section, flowing over a 15 m long mobile sediment bed. The long-term aim is to allow seabed mobility, manifested through scour and liquefaction, to be incorporated in simulations of pipeline on-bottom stability – which currently neglect these potentially important processes.

This project is led by Liang Cheng, with Hongwei An (UWA) and David White and Mark Randolph. Support for this initiative was provided by Andrew Palmer (National University of Singapore), as well as Woodside (Nino Fogliani and Roland Fricke) and the local consultancies JP Kenny (Terry Griffiths) and Atteris (Eric Jas). Conference papers describing the O-tube activity were presented at the Offshore Pipeline Technology Conference (in Amsterdam) and the ISOPE Conference (Shanghai).

Scott Draper with the miniature o-tube

the large o-tube, assembled at the uwa Shenton Park field station

O-tubeA new O-tube facility allows storm conditions to be simulated within a large recirculating flume.


the monash advance Pipe testing System (maPS)

Among these, propagation buckling is the most critical one, particularly in deep water, and can quickly damage many kilometres of pipeline.

A local buckle, ovalisation, dent or corrosion in the pipe wall can quickly transform the pipe cross-section into a dumb-bell (or dog bone) shape that travels along the pipeline as long as the external pressure is high enough to sustain propagation. The lowest pressure that maintains propagation is the propagation pressure that is only a small fraction of the elastic collapse pressure of the intact pipe. This results in a substantial

increase in material and installation cost of the pipeline, since design is therefore governed by propagation pressure.

A hyperbaric chamber was constructed for the simulation of propagation buckling in ultra-deep subsea pipelines. The pressurised testing vessel is 4 m long with an internal diameter of 173mm and is rated for 20 MPa (2000 m water depth). A testing protocol was successfully established and numerous tests were conducted on 3m long steel and aluminium pipes. A simple testing procedure using a ring segment of the pipeline was also established as a preliminary test. A modified analytical

solution for propagation buckling was proposed and a finite element model was established and verified with the experimental results. Based on these findings, a new pipe topology is proposed. Finite element analysis of the new pipe, a faceted cylinder, shows a substantial increase in buckling capacity for the same diameter/thickness ratio.

The coupling of upheaval and lateral buckling with propagation buckling is being investigated together with exploring the possible modification of the hyperbaric chamber to simulate this form of coupled buckling.

A sophisticated 2D electrical actuator with a precision of 0.01 mm/sec (to account for the slow axial walking process) was devised to simulate the pipe motion on a laboratory-made clay seabed. A horizontal linear motor capable of driving the shaft with a drive force between 300 to 500 N for a stroke length of 200 mm is provided. The vertical motion is controlled by a motor providing 200 to 300 N drive force to an expected stroke length of 200 mm. Both load and

displacement controlled cycles can be performed at different rates depicting both undrained and drained conditions. The system is suitable for element testing of typical prototype pipe diameters.

Dummy sections at the ends of the test pipe section are provided to reduce boundary effects in simulation of a long pipe. The following steps are used in a typical experiment. First, a model seabed is prepared and characterised using a T bar.

Second, the test pipe is allowed to settle on the model seabed. Third, the test pipe is subjected to cyclic axial displacements using the horizontal actuator. On the basis of instrumentation provided, the axial on the test pipe section, pore water pressure at pre-determined locations and vertical settlement of pipe are measured. The test results produce the shear stress-displacement characteristics of the pipe-soil interface applicable to axial walking problems.

Propagation buckling A subsea pipeline can experience a number of structural instabilities, such as lateral (snaking) buckling, upheaval buckling, span formation and propagation buckling.

Axial pipeline walking A testing system to investigate axial pipeline walking under drained and undrained conditions has been established at Monash University, Australia.

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The shear cell consists of a 100 mm long, 250 mm wide and 1.21 mm thick smooth plate supported on thin tubular sway legs, with displacement measured by an eddy-current sensor which resolves plate movement to 0.001 mm. The wave flume was equipped with a computer-controlled piston wave-maker having a maximum stroke length of 1.2 m and capable of generating most types of waves including solitary waves and bores. The experimental model was set up to represent a continental slope and shelf region, with measurements made on the slope and horizontal sections. Measurements were made over both a smooth bed and a rough bed. Both non-breaking and breaking (bores) were investigated. Microsonic® ultrasonic wave gauges were used to measure the wave heights and a SONTEK® 2D Acoustic Doppler Velocimeter was used to measure the flow velocities. A photo of

a physical model test for a solitary wave is shown below. Numerical modelling of the laboratory experiments has been performed and used to calibrate and test a tsunami model for prediction of seabed shear stresses in the field.

Numerical modelling of tsunami sources along the Sunda Arc has shown the locations of principal hazard on the WA continental slope and shelf, together with hotspots of high bed shear stress, both of which can be utilised in pipeline routing studies.

a solitary wave at the shelf edge in the uQ experiments

Tsunami testing facility Novel bed shear stress measurements were performed in the UQ tsunami wave flume, which is 25 m long and 0.8 m wide.


Battery operated, and mounted in pressure proof housings, the equipment controls the operation of the modems and monitors their performance while simultaneously monitoring ambient noise and the water column temperature profile. It has been successfully used for several experiments, including a 16-day unattended trial in 100 m of water off the Western Australian coast. It can be readily modified to suit other types of underwater acoustic modems.

The development of this hardware has been complemented by the development of a modem performance simulator that can be used to investigate the effects of different environmental factors on communication link performance.

Acoustic modems The capability to perform at-sea evaluations of underwater acoustic communication links has been enhanced by the development of equipment to allow the unattended, autonomous operation and monitoring of such links for extended periods of time.

experimental setup for the long-term trial showing all equipment used in the deployment.two sets of equipment were deployed which periodically communicated with one another while recording information including ambient noise levels and a temperature profile for the bottom 50 m of the water column.

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The developed algorithms must, however, be physically validated using a real vehicle equipped with the necessary sensors and actuators.

The majority of AUVs currently available from vendors are either closed architecture which would prevent alternative algorithms from being used on the vehicle, or are too expensive, or too small to be useful. The decision was therefore taken to custom build a modular vehicle that can satisfactorily validate the developed algorithms and with enough flexibility to meet the range of survey/intervention requirements posed by the offshore oil and gas. This vehicle is currently being built in collaboration with the Australian Maritime College. The vehicle is equipped with four lateral thrusters as well as one propulsion thruster permitting it to hover and hold

position while deploying instruments into the seabed, and turn tightly while manoeuvring close to obstacles. The AUV is equipped with forward looking and bathymetry plus side scan sonar to

build 3D relief maps of the seabed and track pipelines and obstacles. It also has doppler velocity sensors and IMUs for navigation, as well other instruments for acoustic and radio communications.

CaD image of an auV

Autonomous underwater vehiclesThe algorithms developed to control, navigate and guide AUVs have all been tested numerically using realistic purpose-built simulators.

Matt HodderGeotechnical analysis of offshore pipelines and steel catenary risersMatt Hodder’s thesis investigated the interaction of cylindrical objects with soil, and its application to the analysis and design of offshore pipelines and risers.

The behaviour observed during experiments performed to assess the effect of various loading conditions on pipe-soil interaction response was used to develop analytical models appropriate to use in an integrated soil-structure interaction assessment of the pipe-soil system. The apparatus and analysis methodology developed allows comparisons of behaviour observed during experiments performed using a short ‘element’ of pipeline assuming two-dimensional plane-strain conditions and the validation of pipe-soil interaction models developed from element tests.

This thesis progresses the understanding of geotechnical aspects of offshore pipeline and riser behaviour. It also advances the predictive capabilities of pipe-soil interaction models, enabling more accurate response assessment and efficient design.

Postgraduateprofile


Publications and disseminationMembers of the Cluster have published 80 journal and 82 conference manuscripts from their research. A further five technical reports were written specifically for the cluster and three book chapters were published. 1. Alam, M. S. and L. Cheng (2009), A 2-D

model to predict time development of scour below pipelines with spoiler, 12th International Conference on Enhancement and Promotion of Computational Methods in Engineering and Science, Hong Kong – Macau.

2. Alam, M. S. and L. Cheng (2009), Blockage ratio and mesh dependency study for Lattice Boltzmann flow around cylinder, 12th International Conference on Enhancement and Promotion of Computational Methods in Engineering and Science Hong Kong – Macau.

3. Alam, M. S. and L. Cheng (2009), Modelling of flow around a square cylinder of different roughness using a lattice Boltzmann model, 28th International Conference on Ocean, Offshore and Arctic Engineering, Honolulu, Hawaii, OMAE2009-80155.

4. Alam, M. S. and L. Cheng (2010), A parallel three-dimensional scour model to predict flow and scour below a submarine pipeline, Central European Journal of Physics, 8(4): 604-619.

5. Albermani, F., H. Khalilpasha and H. Karampour (2011), Propagation buckling in deep subsea pipelines, Pipelines International Digest, January 2011: 7-8.

6. Albermani, F., H. Khalilpasha and H. Karampour (2011), Propagation buckling in deep sub-sea pipelines, Engineering Structures: 33(9): 3547-2553.

7. An, H., L. Cheng nd M. Zhao (2010). Direct numerical simulation of 3D steay streaming induced by Honji Instability. 17th Australasian Fluid Mechanics Conference, Auckland, New Zealand.

8. An, H., L. Cheng and M. Zhao (2010), Steady streaming around a circular cylinder in an oscillatory flow, Ocean Engineering, 36(14): 1089-1097.

9. An, H., Cheng, L., Zhao, M., (2010), Steady streaming around a circular cylinder near a plane boundary due to oscillatory flow. , Journal of Hydraulic Engineering: (accepted).

10. An, H., Cheng, L., Zhao, M. (2011), Direct numerical simulation of oscillatory flow around a circular cylinder at low Keulegan-Carpenter number, Journal of Fluid Mechanics, 666: 77-103.

11. Baldock, T. E., D. Cox, T. Maddux, J. Killian and L. Fayler (2009), Kinematics of breaking tsunami waves: a data set from large scale laboratory experiments, Coastal Engineering, 56: 506-516.

12. Baldock, T. E. and D. Peiris (2011). Overtopping and run-up hazards induced by solitary waves and bores. Tsunami Threat - Research and Technology, In-Tech.

13. Baldock, T. E. and J. K. Seelam (2009), Numerical and physical modelling of tsunami run-up and impact on subsea pipelines, 1st Annual Society for Underwater Technology Subsea Technical Conference (SUT), Perth, CD.

14. Bao, C. X., X.Q Zhu, H. Hao and Z.X. Li (2008), Operational modal analysis using correlation-based ARMA models, 10th International Symposium on Structural Engineering for Young Experts, CD:1459-1464.

15. Bao, C. X., X.Q Zhu, H. Hao and Z.X. Li (2008), Variable modal parameter identification using an improved HHT algorithm, 10th International Symposium on Structural Engineering for Young Experts, CD:1465-1470.

16. Bao, C. X., H. Hao, Z.X. Li and X.Q. Zhu (2009), Time-varying system identification using an improved HHT algorithm, Computers and Structures, 87(23-24): 1611-1623.

17. Barnes, M. P., T. O’Donaghue, J.M. Alsina and T.E. Baldock (2009), Direct bed shear stress measurements in bore-driven swash, Coastal Engineering, 56: 853-867.

18. Barnes, M. P. and T. E. Baldock (2010), A Lagrangian model for boundary layer growth and bed shear stress in the swash zone, Coastal Engineering,(57): 385-396.

19. Boukpeti, N., D.J. White and M.F. Randolph (2009), Characterization of the solid-liquid transition of fine-grained sediments, 28th International Conference on Offshore Mechanics and Arctic Engineering, Honolulu, Hawaii, OMAE2009-79738.

20. Boukpeti, N., D. White and M.F. Randolph (2012) Analytical modelling of the steady flow of a submarine slide and consequent loading on a pipeline, Géotechnique, 62(2) 137-146.

21. Boukpeti, N., D.J. White, M.F. Randolph and H.E. Low (2012), The strength of fine-grained soils at the solid-fluid transition, Geotechnique: in press, posted ahead of print, 10.1680/geot.9.P.069.

22. Boylan, N., C. Gaudin, D.J. White, M.F. Randolph and Schneider, J.A. (2009), Geotechnical centrifuge modelling techniques for submarine slides, 28th International Conference on Offshore Mechanics and Arctic Engineering, Honolulu, Hawaii, OMAE2009-79059.

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Grant PuseyCharacterisation of long-range horizontal performance of underwater acoustic communicationGrant’s study sought to characterise the performance of horizontal underwater acoustic data communication in various scenarios with particular application to subsea monitoring and control systems. This involved conducting field trials to simultaneously measure environmental parameters and communication performance.

An underwater acoustic communication simulator was also developed and the results compared to the experiments. This thesis investigates the environmental dependency of communication performance and the feasibility of using the technology in place of cabled telemetry.

Postgraduateprofile23. Boylan, N., C. Gaudin, D.J. White and M.F.

Randolph (2010), Modelling of submarine slides in the geotechnical centrifuge, 7th International Conference on Physical Modelling in Geotechnics (ICPMG 2010), Zurich, Switzerland CD:1095-1100.

24. Boylan, N. and M. F. Randolph (2010), Enhancement of the ball penetrometer test with pore pressure measurements, 2nd International Symposium on Frontiers in Offshore Geotechnics (ISFOG 2010), Perth, Australia, CD:259-264.

25. Boylan, N. P., C. Gaudin, D.J. White and M.F. Randolph (2012), Centrifuge modelling of submarine slides, Ocean Engineering: under review April 2011.

26. Boylan, N. P. and D. J. White (2010). Geotechnical frontiers in offshore engineering - invited keynote lecture. International Symposium on Recent Advances and Technologies in Coastal Development, Tokyo, Japan, CD: 18 pages.

27. Cassidy, M.J. and Y. Tian (2007), Technical note on pipesoil data interaction model testing, GEO:08451.

28. Cassidy, M.J. and Y. Tian (2008), Technical note on implementation of UWAPIPE into ABAQUS, GEO:07421.

29. Chatterjee, S., D.J. White, D. Wang and M.F. Randolph (2010), Large deformation finite element analysis of vertical penetration of pipelines into the seabed, 2nd International Conference in Frontiers in Offshore Geotechnics (ISFOG 2010), Perth, Australia, n/a:785-790.

30. Cheng, L., K. Yeow, Z. Zang and B. Teng (2009), Three-dimensional scour below pipelines in steady currents, Coastal Engineering, 56(5-6): 577-590.

31. Davies, M. C. R., E.T. Bowman and D.J. White (2010), Physical modelling of natural hazards - a keynote lecture, 7th International Conference on Physical Modelling in Geotechnics (ICPMG 2010) Zurich, Switzerland, CD:3-22.

32. DeJong, J., N. Yafrate, D. DeGroot, H.E. Low and M.F. Randolph (2010), Recommended practice for full flow penetrometer testing and analysis, ASTM Geotechnical Testing Journal, 33(2): 13 pages.

33. DeJong, J. and M. F. Randolph (2012), Influence of partial consolidation during cone penetration on estimated soil behaviour type and pore pressure dissipation measurements, Journal of Geotechnical & Geoenvironmental Engineering, 138(7): 777-788.

34. DeJong, J. T., N.J. Yafrate and M.F. Randolph (2008), Use of pore pressure measurements in a ball full-flow penetrometer, 3rd International Conference on Site Characterization, Taiwan, 1269-1275.

35. Gaudin, C., D.J. White, N. Boylan, J. Breen, T.A. Brown, S. De Catania and P. Hortin (2009), A wireless high speed data acquistion for geotechnical centrifuge model testing, Measurement Science and Technology, 20(9): 11 pages.

36. Guard, P. A., T.E. Baldock and P. Nielsen (2009), Bed shear stress in unsteady flow, Coasts and Ports, Wellington, NZ.

37. Hodder, M., M.J. Cassidy and D. Barrett (2008), Undrained response of pipelines subjected to combined vertical and lateral loading, 2nd International Conference on Foundations (ICOF), Bracknell, UK, CD:897-908.

38. Hodder, M. S., White, D.J., Cassidy, M.J. (2012) An effective stress framework for the variation in penetration resistance due to episodes of remoulding and reconsolidation, Géotechnique, 63(1): 30-43.

39. Hodder, M. S., D.J. White and M.J. Cassidy (2009), Effect of remoulding and reconsolidation on the touchdown stiffness of a steel catenary riser: Observations from centrifuge modelling, 41st Offshore Technology Conference, Houston, Texas, OTC-19871.

40. Hodder, M. S. and M. J. Cassidy (2010), A plasticity model for predicting the vertical and lateral behaviour of pipelines in clay soils, Geotechnique, 60(4): 247–263.

41. Hodder, M. S., D. J. White, et al. (2010), Analysis of strength degradation during episodes of cyclic loading, illustrated by the T-bar penetration test, International Journal of Geomechanics, 10(3): 117-123.

42. Jaeger, R. A., J.T. DeJong, R.W. Boulanger, H.E Low and Randolph, M.F. (2010), Variable penetration rate CPT in an intermediate soil, 2nd International Symposium on Cone Penetration Testing, CPT10, Huntington Beach, California.

43. Khalilpasha, H. (2010). Buckling propagation of subsea pipelines. EAIT Postragraduate Student Conference, Queensland, Australia.

44. Khalilpasha, H. (2011). Nonlinear numerical investigation of buckle propagation in subsea pipelines. The 1st International Postgraduate Conference on Engineering, Designing and Developing the Built Environment for Sustainable Wellbeing, Brisbane, Australia.

45. Khalilpasha, H. and F. Albermani (2011). On the propagation buckling and effects in ultra-long deep subsea pipelines. 30th International Conference on Ocean, Offshore and Arctic Engineering (OMAE 2011), Rotterdam, The Netherlands.

46. Kodikara, J. K. (2008). Study of the axial response and its coupling of the general pipe-soil interaction of seabed pipelines.

47. Kokegei, M., F. He and K. Sammut (2008), Fully-coupled 6 degress-of-freedom control of autonomous underwater vehicles, IEEE Oceans 2008, submitted July 2008.

48. Kokegei, M., F. He and K. Sammut (2009), Nonlinear fully-coupled control of AUVs, 1st Annual Society for Underwater Society Subsea Technical Conference (SUT), Perth.

49. Kokegei, M., He, F. and Sammut, K. (2011). Fully coupled 6 DoF control of an over-actuated autonomous underwater vehicle. Underwater Vehicles, InTech.

50. Lammas, A., K. Sammut and He, F. (2008), Improving navigational accuracy for AUVs using the MAPR particle filter, IEEE Oceans 2008.

51. Lammas, A., K. Sammut and He, F. (2009). 6-DoF navigation systems for autonomous underwater vehicles. Mobile Robots Navigation, In-Tech Books.

52. Lammas, A., K. Sammut and He, F. (2009), MAPR particle filter for AUV sensor fusion, 1st Annual Society for Underwater Society Subsea Technical Conference (SUT), Perth.

53. Lammas, A. S., K. and He, F. (2012), Measurement-assisted partial resampling particle filter for full-order state-estimation of an AUV’s hydrodynamic parameters, IEEE Oceanic Engineering: submitted April 2011.

54. LeBlanc, C. and M. F. Randolph (2008), Interpretation of piezocones in silt, using cavity expansion and critical state methods, 12th International Conference of International Association for Computer Methods and Advances in Geomechanics (IACMAG), Goa, India, CD:822-829.

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

56. Lehane, B., C. O’Loughlin, C. Gaudin and M.F. Randolph (2009), Rate effects on penetrometer resistance in kaolin, Geotechnique, 59(1): 41-52.

57. Li, Y. H., K.Q. Fan, X.Q. Zhu and H. Hao (2009), Operational modal identification of offshore structures using blind source separation, 1st Annual Society for Underwater Technology Subsea Technical Conference (SUT), Perth, CD: SUT09-LiYH.

58. Liu, H. B., X.L. Zhao and Z.G. Xiao (2010), Fatigue testing of subsea pipeline steel connections under combined actions, The 21st Australasian Conference on the Mechanics of Structures and Materials, Melbourne, 649-655.

59. Liu, H. B. and X. L. Zhao (2011). Predictions of fatigue life of steel connections under combined actions using boundary element method. 21st International Offshore and Polar Engineering Conference, Maui, Hawaii, 4: 276-281.

60. Liu, H. B. and X. L. Zhao (2012). Fatigue behaviours of subsea pipeline steel connections under combined actions. 7th International Conference on Advances in Steel Structures, Nanjing, China.

61. Liu, H. B. and X. L. Zhao (2012). Fracture mechanics analysis of steel connections under combined actions. 7th International Conference on Advances in Steel Structures, Nanjing, China.

62. Liu, H. B. and X. L. Zhao (2012). Repair efficiency of CFRP reinforced steel connections under combined actions. 6th International Conference on Fibre Reinforced Polymer Composites in Civil Engineering, Rome, Italy.

63. Liu, H.B, and X.L. Zhao (2012), Fatigue Behaviour of Welded Steel Connections under Combined Actions, Advances in Structural Engineering – An International Journal, 15(10): 1817-1828.

64. Liu, H.B and X.L. Zhao (2013), Prediction of fatigue life for CFRP strengthened steel connections under combined loads, International Journal of Structural Stability and Dynamics, 12(6): DOI: 10.1142/S0219455412500599

65. Low, H. E., M.F. Randolph, C.J. Rutherford, B.B. Bernard and J.M. Brooks (2008), Characterization of near seabed surface sediment, Offshore Technology Conference, OTC19149.

66. Low, H. E., M.F. Randolph, J.T. DeJong and N.J. Yafrate (2008), Variable rate full-flow penetration tests in intact and remoulded soil, 3rd International Conference on Site Characterization, Taiwan, 1087-1092.

67. Low, H. E., T. Lunne, K.H. Andersen, M.A. Sjursen, M.A., X. Li and M.F. Randolph (2010), Estimation of intact and remoulded undrained shear strengths from penetration tests in soft clays, Geotechnique, 60(11): 843-859.

68. Low, H. E., M. F. Randolph, T. Lunne, K.H. Andersen and M.A. Sjursen (2011) Effect of soil characteristics on relative values of piezocone, T-bar and ball penetration resistance, Geotechnique, 61 (8): 651-664.

69. Low, H. E., M.M. Landon, M. F. Randolph and D. DeGroot, (2011) Geotechnical characterisation and engineering properties of Burswood clay, Geotechnique, 61 (7): 575-591.

70. Low, H. E. and M. F. Randolph (2010), Strength measurement for near seabed surface soft soil, Journal of Geotechnical and Geoenvironmental Engineering, 136(11): 1565-1573.

71. Lunne, T., K.H. Andersen, H..E. Low, M. F. Randolph and M.A. Sjursen, (2011) Guidelines for offshore in situ testing and interpretation, Canadian Geotechnical Journal, 48(4): 543-556.

72. Mahmoodzadeh, H., N, Boylan, M.F. Randolph and M.J. Cassidy (2011). The effect of partial drainage on measurements by a piezoball penetrometer. 30th International Conference on Ocean Offshore and Arctic Engineering (OMAE2011), Rotterdam, The Netherlands.

73. Merifield, R. S., D.J. White and M.F. Randolph (2008), The effect of pipe-soil interface conditions on undrained breakout resistance of partially-embedded pipelines, 12th International Conference on Advances in Computer Methods and Analysis in Geomechanics (IACMAG), Goa, India, CD:4249-4256.

74. Merifield, R. S., D.J. White and M.F. Randolph (2009), The effect of surface heave on the response of partially-embedded pipelines on clay, Journal of Geotechnical and Geoenvironmental Engineering, 135(6): 819-826.

Bassem YoussefThe Integrated Stability Analysis of Offshore PipelinesThe dissertation is concerned with the stability analysis of offshore pipelines under wave and current loading. An integrated hydrodynamic-pipe-soil modeling program is developed and used in investigating the pipeline stability in conditions found on the Australian North West Shelf and the Gulf of Mexico. The developed program is a combination of three individual programs to perform an integrated pipeline simulation. A hydrodynamic modelling program that generates 3D ocean surface, estimates the wave kinematics at the pipeline level and calculates the hydrodynamic loads on the pipeline. A pipe-soil modelling program that simulates the complicated pipe-soil interaction behaviour under complex hydrodynamic loading. The pipeline is modelled using the commercial finite element program ABAQUS.

Advanced statistical methods are utilized in the thesis to investigate the reliability of the pipeline stability and the sensitivity of the design input parameter. Pipeline centrifuge modeling is conducted under complex hydrodynamic loading, with the results used to validate the integrated program. The study provides engineers with a 3D pipeline modeling program and methodologies to achieve reliable and economic pipeline designs.

Bassem received an Innovation Award Commendation from the Australian Gas Technology Conference (Perth-2012) for the development of the integrated pipeline simulation program.

Postgraduateprofile

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75. Osman, A. S. and M. F. Randolph (2010), Response of a solid infinite cylinder embedded in a poroelastic medium and subjected to a lateral load, International Journal of Solids and Structures, 47(18-19): 2414-2424.

76. Peng, X. L. and H. Hao (2008), Damage detection of underwater pipeline using vibration-based method, 3rd World Congress on Engineering Asset Management and Intelligent Maintenance System.

77. Pusey, G., A. Duncan and A. Smerdon (2009), Analysis of acoustic modem performance for long range horizontal data transmission, OCEANS 09 IEEE Bremen, Germany.

78. Pusey, G. (2011). Characterisation of long-range horizontal performance of underwater acoustic communication, Curtin University, PhD Thesis.

79. Pusey, G. and A. Duncan (2008), Characterisation of underwater acoustic modem performance for real-time horizontal data transmission, Australian Acoustical Society Annual Conference 2008, Geelong.

80. Pusey, G. and A. Duncan (2009), Development of a simplistic underwater acoustic channel simulator for analysis and prediction of horizontal data telemetry, Australian Acoustical Society National Conference, Adelaide, abstract submitted.

81. Pusey, G. and A. Duncan (2009), An investigation of oceanographic parameters affecting acoustic modem performance for horizontal data transmission, Underwater Acoustic Measurements Technologies and Results 3rd International Conference and Exhibition, Nafplion, Greece.

82. Pusey, G. and A. Duncan (2009), A preliminary study of underwater acoustic communications over horizontal ranges, 1st Annual Society for Underwater Society Subsea Technical Conference (SUT) Perth, CD.

83. Randolph, M. F., D. Wang, H. Zhou, M.S. Hossain and Y. Hu (2008), Large deformation finite element analysis for offshore applications, 12th International Conference of International Association for Computer Methods and Advances in Geomechanics (IACMAG), Goa, India, CD:3307-3318.

84. Randolph, M. F., D. Seo and D.J. White (2010), Parametric solutions for slide impact on pipelines, Journal of Geotechnical & Geoenvironmental Engineering, 136(7): 940-949.

85. Randolph, M. F., C. Gaudin, S.M. Gourvenec, D.J. White, N. Boylan and M.J. Cassidy (2011), Recent advances in offshore geotechnics for deepwater oil and gas developments, Ocean Engineering, special issue: 38(7): 818-834.

86. Randolph, M. F. and P. Quiggin (2009), Non-linear hysteretic seabed model for catenary pipeline contact, 28th International Conference on Offshore Mechanics

and Arctic Engineering (OMAE 2009), Honolulu, Hawaii, OMAE2009-79259.

87. Randolph, M. F. and D. J. White (2008), Offshore foundation design – a moving target. Keynote paper, 2nd International Conference on Foundations (ICOF), Bracknell, UK, 27-59.

88. Randolph, M. F. and D. J. White (2008), Pipeline embedment in deep water processes and quantitative assessment, Offshore Technology Conference, OTC19128.

89. Randolph M.F. and D.J. White (2012), Interaction forces between pipelines and submarine slides - a geotechnical viewpoint. Ocean Engineering, 48, 32-37.

90. Rognon, P. G., I. Einav and C. Gay (2010), Internal relaxation time in immersed particulate materials, Physical Review E, 81: 061304.

91. Rognon, P. G., I. Einav, J. Bonivin and T. Millar (2010),A scaling law for heat conductivity in sheared granular material, Europhysics Letters, 89, pp 58006.

92. Rognon, P. G. and C. Gay (2008), Soft dynamics simulation 1: normal approach of two deformable particles in a viscous fluid and optimal-approach strategy, The European Physics Journal, 27: 253-260.

93. Rognon, P. G. and C. Gay (2009), Soft dynamics simulation 2: elastic spheres undergoing T1 process in a viscous fluid, The European Physics Journal, 30: 291-301.

94. Schneider, J. A., M.F. Randolph, P.W. Mayne and N. Ramsey (2008), Analysis of factors influencing soil classification using normalized piezocone tip resistance and pore pressure parameters, Journal of Geotechnical and Geoenvironmental Engineering, 134(11): 1569-1586.

95. Schneider, J. A., M.F. Randolph, P.W. Mayne and N. Ramsey (2008), Influence of partial consolidation during penetration on normalised soil classification by piezocone, 3rd International Conference on Site Characterization, Taiwan, 1159-1165.

96. Seelam, J. K., P.A. Guard and T.E. Baldock (2011), Measurements and modelling of bed shear stress under solitary waves, Coastal Engineering, 58: 937-947.

97. Seelam, J. K. and T. E. Baldock (2009), Direct bed shear stress measurements under solitary tsunami-type waves and breaking tsunami wavefronts, International Conference on Coastal Dynamics, Tokyo, Japan.

98. Seelam, J. K. and T. E. Baldock (2009), Role of submarine canyon on tsunami amplification on south east coast of India, International Conference of Asia Oceania Geosciences Society, Singapore, poster presentation.

99. Seelam, J. K. and T. E. Baldock (2010), Measurements and modelling of direct bed shear stress under solitary waves, 9th International Conference on Hydro-Science and Engineering, Chennai, India, 421-430.

100. Seelam, J. K. and T. E. Baldock (2011). Tsunami induced bed shear strewsses on Northwest Coast of Australia. International Conference of Asia Oceania Geosciences Society (AOGS2011), Taiwan.

101. Seelam, J. K. and T. E. Baldock (2011). Tsunami induced shear stresses along submarine canyons off south-east coast of India. 6th International Conference on Asia and Pacific Coasts (APAC2011), Hong Kong.

102. Seelam, J. K. and T. E. Baldock (2012). Solitary wave friction factors from direct shear measurements on a sloping bed. 8th International Conference on Coastal and Port Engineering in Developing Countries, Madras, India.

103. Seelam, J. K. and T. E. Baldock (2011), Comparison of bed shear under non-breaking and breaking solitary waves, International Journal of Ocean and Climate Systems: 2(4): 259-278.

104. Senthilkumar, M., P. Rajeev, P. and J. Kodikara (2010). Offshore pipe clay-seabed interaction in axial direction. Cluster workshop: abstract.

105. Senthilkumar, M., J. Kodikara and P. Rajeev (2011). Numerical modelling of undrained vertical load-deformation behaviour of seabed pipelines. 13th International Confernce of the International Association for Computer Methods and Advances in Geomechanics (IACMAG 2011), Melbourne, Australia.

106. Senthilkumar, M., J. Kodikara and P. Rajeev (2011). Numerical modelling of vertical load-displacement behaviour of offshore pipeline using coupled analysis. Pan Am CGS Geotechnical Conference, Toronto, Canada.

107. Senthilkumar, P. R., M., J. Kodikara and N.I. Thusynathan (2011). Laboratory modelling of pipe-clay seabed interaction in axial direction. International Symposium of Offshore and Polar Engineering 2011, Maui, Hawaii.

108. Sleelam, J. K., Baldock, T.E. (2010), Tsunami induced currents in vicinity of Palar submarine canyon off south-east coast of India – a numerical model study, Poster presentation at International Conference of Asia Oceania Geosciences Society (AOGS 2010), India.

109. Tian, Y., M.J. Cassidy and G. Gaudin, (2008), Pipeline integrity: centrifuge modelling of pipes in sand, Geo:09475.

110. Tian, Y., M.J. Cassidy and C. Gaudin (2010), Advancing pipe-soil interaction models through geotechnical centrifuge testing in calcareous sands, Applied Ocean Research, 32(3): 284-297.

111. Tian, Y., M.J. Cassidy and B.S. Youssef (2010). Consideration for on-bottom stability of unburied pipelines using force-resultant models. 20th International Offshore and Polar Engineering Conference (ISOPE), Beijing, China, 2: 212-219.


112. Tian, Y., M.J. Cassidy and C. Gaudin (2011). Centrifuge tests of shallowly embedded pipeline on undrained and partially drained silt sand. GEO: 11560.

113. Tian, Y., D. Wang and M.J. Cassidy (2011). Large deformation finite element analysis of offshore geotechnical penetration tests. 2nd International Symposium on Computational Mechanics (ComGeo11), Cavtat-Dubrovnik, Croatia.

114. Tian, Y., M.J. Cassidy and B.S. Youssef (2011), Consideration for on-bottom stability of unburied pipelines using a dynamic fluid-structure-soil simulation program, International Journal of Offshore and Polar Engineering: 21(3): 1-8.

115. Tian, Y. and M. J. Cassidy (2008), Explicit and Implicit integration algorithms for an elastoplastic pipe-soil interaction macroelement model, 27th International Conference on Offshore Mechanics and Arctic Engineering, OMAE2008-57237.

116. Tian, Y. and M. J. Cassidy (2008), Modelling of pipe-soil interaction and its application in numerical simulation, International Journal of Geomechanics, 8(4): 213-229.

117. Tian, Y. and M. J. Cassidy (2008), A practical approach to numerical modelling of pipe-soil interaction, 18th International Offshore and Polar Engineering Conference (ISOPE), Vancouver, Canada, 2:533-538.

118. Tian, Y. and M. J. Cassidy (2009), Pipe-soil interaction analysis with a 3D macroelement model, 19th International Offshore and Polar Engineering Conference (ISOPE), Osaka, Japan, 461-468.

119. Tian, Y. and M. J. Cassidy (2010), The challenge of numerically implementing numerous force-resultant models in the stability analysis of long on-bottom pipelines, Computers and Geotechnics, 37(1-2): 216-232.

120. Tian, Y. and M. J. Cassidy (2010), A pipe-soil interaction model incorporating large lateral displacements in calcareous sand, Journal of Geotechnical & Geoenvironmental Engineering, 137(3): 279-287.

121. Tian, Y. and M. J. Cassidy, (2013), Equivalent absolute lateral static stability of on-bottom offshore pipelines, Australian Geomechanics Journal, under review November.

122. Tian, Y. and M. J. Cassidy (2011), Incorporating uplift in the analysis of shallowly embedded pipelines: Int. Journal of Structural Engineering and Mechanics, 40(1): 29-48.

123. Tran, D. S. and V. M. Tran (2010). Propagation of buckle in subsea pipelines, BE Thesis, University of Queensland.

124. Wang, D., D.J. White and M.F. Randolph (2009), Numerical simulations of dynamic embedment during pipe laying on soft clay, 28th International Conference on Offshore Mechanics and Arctic Engineering, Honolulu, Hawaii, OMAE2009-79199.

125. Wang, D., D.J. White and M.F. Randolph (2010), Large deformation finite element analysis of pipe penetration and large-amplitude lateral displacement, Canadian Geotechnical Journal, 47(8): 842-856.

126. Wang, D., M.F. Randolph and D.J. White (2012), A dynamic large deformation finite element method and element addition technique, International Journal for Geomechanics: under review April 2011.

127. Wang, Y., X.Q. Zhu, H. Hao and K.Q. Fan (2009), Development and testing of guided wave techniques for pipeline integrity monitoring, 1st Annual Society for Underwater Society Subsea Technical Conference (SUT), Perth, CD:SUT009-WangY.

128. Westgate, Z., D.J. White and M.F. Randolph (2009), Video observations of dynamic embedment during pipelaying, 28th International Conference on Offshore Mechanics and Arctic Engineering (OMAE 2009), Honolulu, Hawaii, OMAE2009-79814.

129. Westgate, Z., M.F. Randolph, M.F, D.J. White and S. Li (2010), The influence of seastate on as laid pipeline embedment: a case study, Applied Ocean Research, 32(4): 321-331.

130. Westgate, Z., D.J. White and M.F. Randolph (2010), Pipeline laying and embedment in soft fine-grained soils: field observations and numerical simulations., Offshore Technology Conference, Houston, OTC2010:Paper number 20407.

131. Westgate, Z. J., M.F. Randolph and D.J. White (2010), Theoretical, numerical and field studies of offshore pipeline sleeper crossings, 2nd International Symposium on Frontiers in Offshore Geotechnics, Perth, Australia, n/a:845-850.

132. White, D. J., C. Gaudin, N. Boylan and H. Zhou (2010), Interpretation of T-bar penetrometer tests at shallow embedment and in very soft soils, Canadian Geotechnical Journal, 47(2): 218-229.

133. White, D. J. and D. N. Cathie (2010). Geotechnics for subsea pipelines – a keynote lecture. 2nd International Symposium on Frontiers in Offshore Geotechnics, Perth, Australia, n/a: 87-123.

134. White, D. J. and M. S. Hodder (2010), A simple model for the effect on soil strength of remoulding and reconsolidation, Canadian Geotechnical Journal, 47(7): 821-826.

135. Wu, D., L. Cheng and M. Zhao (2010), Numerical and experimental study of natural backfill of pipeline in a trench under steady currents, International Conference on Ocean, Offshore and Arctic Engineering (OMAE2010), Shanghai, China, CD:OMAE2010-20325.

136. Xiao, Z. G. and X. L. Zhao (2007), Current status of research into subsea pipelines subjected to fatigue loading, International Institute of Welding Asian Pacific Congress, Stream 1 – Structures/Pipelines:Paper 1.34.

137. Xiao, Z. G. and X. L. Zhao (2007), Frequency analyses of free spanning subsea pipelines with finite element method, 5th International Conference on Advances in Steel Structures, 3:645-650.

138. Xiao, Z. G. and X. L. Zhao (2008), Stress analyses of free spanning subsea pipelines with finite element method, 10th International Symposium on Structural Engineering for Young Experts.

139. Xiao, Z. G. and X. L. Zhao (2010), Prediction of Natural Frequency of Free Spanning Subsea Pipelines, International Journal of Steel Structures, 10(1): 81-90.

140. Xiao, Z. G. and X. L. Zhao (2010), Frequency analyses of free spanning subsea pipelines, International Journal of Steel Structures 10(1): 1598-2531.

141. Yafrate, N. J., J.T. DeJong, D. DeGroot and M.F. Randolph (2009), Evaluation of remolded shear strength and sensitivity of soft clay using full flow penetrometers, Journal of Geotechnical and Geoenvironmental Engineering, 135(9): 1179-1189.

142. Yan, Y., White, D.J. and Randolph, M.F. (2010), Investigation into the toroid penetrometer on non-homogeneous clay, 2nd International Symposium on Frontiers in Offshore Geotechnics (ISFOG2010), Perth, Western Australia, CD:321-326.

143. Yan, Y., D.J. White and M.F. Randolph (2011), Penetration resistance and stiffness factors in uniform clay for hemispherical and toroidal penetrometers, International Journal for Geomechanics: 11(4): 263-275.

144. J.T. Yi, S.H. Goh, F.H. Lee and M.F. Randolph,(2012), A numerical study of cone penetration in fine-grained soils allowing for consolidation effects, Géotechnique, 62(8): 707 –719.

145. Youssef, B. S., M.J. Cassidy and Y. Tian (2010), Balanced three-dimensional modelling of the fluid-structure-soil interaction of an untrenched pipeline, 20th International Offshore and Polar Engineering Conference (ISOPE), Beijing, China, 2:123-130.

146. Youssef, B. S., Y. Tian and M.J. Cassidy (2011). Probabilistic modes application in the integrated stability analysis of offshore on-bottom pipeline. 30th International Conference on Offshore Mechanics and Arctic Engineering (OMAE2011): OMAE50047.

147. Zang, Z., L. Cheng, M. Zhao, D. Liang and B. Teng (2009), A numerical model for onset of scour below offshore pipelines, Ocean Engineering, 56: 458-466.

148. Zang, Z., L. Cheng and M. Zhao (2010), Onset of scour below pipeline under combined waves and current, International Conference on Ocean, Offshore and Arctic Engineering (OMAE2010), Shanghai, China, CD:OMAE2010-20719.

33

Yue’s thesis focused on establishing a theoretical understanding for the response of a new class of seabed penetrometers – the toroid and ball penetrometers – designed specifically for pipe-soil interactions without the difficulty of end effects. In view of the perceived need to improve the pipe design guidelines and develop more reliable procedures for estimating the axial interaction between pipe and soil, this study explored toroid and ball penetrometer performance on clays through centrifuge model tests and small strain finite element analyses. There was also an emphasis on the axial interaction in isolation at shallow embedment ratio, but some possible way of its incorporation into a more general interaction modelling scheme are examined. The aim of the research was to:

◆ Provide an improved quantitative framework to characterise the undrained surficial soft sediments which will conclude (a) suggest undrained resistance factors

Yue YanNovel methods for characterising pipe-soil interaction forces in situ in deep water

under vertical and torsional loading appropriate for toroid and ball penetrometer at shallow embedment depths (b) allow operative soil stiffness to be estimated, or for the penetrometer stiffness to be converted into pipe-soil stiffness as required.

◆ Investigating the drainage of soil during penetration and torsional loadings. The key effect is to provide robust dissipation solutions specifically for these two new penetrometers, which enables the measured pore pressure to be interpreted in terms of the consolidation characteristic of the soil.

◆ Develop a testing framework and a more reliable interpretation method for the near surface seabed soft soil.

◆ Provide recommendations on the design of in these in situ tools and associated testing procedures which will lead to more reliable and less conservative assessments of axial friction.

The ultimate aim of this research is to develop a theoretical understanding of the behaviour of a shallowly embedded spherical and toroid penetrometer subjected to vertical and torsional loading, and to prove through physical modelling the concept of this new site characterisation tool focusing on axial interaction between a pipeline and soil.

Postgraduateprofile

149. Zang, Z., L. Cheng and M. Zhao (2010). Onset of scour below pipeline under combined waves and current. 29th International Conference on Offshore Mechanics and Arctic Engineering (OMAE2010), Shanghai, China, CD: OMAE2010-20325.

150. Zang, Z. and L. Cheng (2012), Numerical simulation on sand waves behaviour and their interaction with pipelines by ROMS model, Ocean Engineering: submitted 2011.

151. Zhao, M., L.Cheng and T. Zhou (2009), Numerical simulation of three-dimensional flow past a yawed circular cylinder, Journal of Fluids and Structures, 25(5): 831-847.

152. Zhao, M., L.Cheng and Z. Zang (2010), Experimental and numerical investigation of local scour around a submerged vertical circular cylinder in steady currents, Coastal Engineering, 57: 709-721.

153. Zhao, M. and L. Cheng (2008), Numerical simulation of local scour below a vibrating pipeline in currents, 4th International Conference on Scour and Erosion, 233-239.

154. Zhao, M. and L. Cheng (2009), Experimental investigation of local scour around a submerged vertical circular cylinder in steady currents,

28th International Conference on Ocean, Offshore and Arctic Engineering (OMAE 2009), OMAE2009-79148.

155. Zhao, M. and L. Cheng (2010), Finite element analysis of flow control using porous media, Ocean Engineering, 37: 1357-1366.

156. Zhao, M. and L. Cheng (2010), Numerical investigation of local scour below a vibrating pipeline under steady currents, Coastal Engineering, 57: 397-406.

157. Zhao, M. and L. Cheng (2010), Numerical investigation of vortex-induced vibration of a circular cylinder close to a plane boundary., International Conference on Ocean, Offshore and Arctic Engineering, OMAE2010, Shanghai, China, OMAE2010-21147.

158. Zhao, M. and L. Cheng (2010). Three-dimensional numerical simulation of hydrodynamic forces on an oblique cylinder in oscillatory flow. 17th Australasian Fluid Mechanics Conference, Auckland, New Zealand, Pen Drive: Paper 042.

159. Zhou, H., D.J. White and M.F. Randolph (2008), Physical and numerical simulation of shallow penetration of a cylindrical object in soft clay, GeoCongress

Characterization, Monitoring and Modelling of Geosystems, 179: 108-117.

160. Zhou, H. and M. F. Randolph (2009), Numerical investigations into cycling of full-flow penetrometers in soft clay, Geotechnique, 59(10): 801-812.

161. Zhou, H. and M. F. Randolph (2009), Resistance of full-flow penetrometers in rate-dependent and strain-softening clay, Geotechnique, 59(2): 79-86.

162. Zhou, H. and M. F. Randolph (2011), Effect of shaft on resistance of a ball penetrometer, Geotechnique, 61 (11): 973-981.

163. Zhou, T., H. Wang, S. F. Mohd Razali, Y. Zhou and L. Cheng (2010), Three-dimensional vorticity measurements in the wake of a yawed circular cylinder, Physics of Fluids, 22(1): 015108.

164. Zhu, H. and M. F. Randolph (2011), Numerical analysis of a cylinder moving through rate-dependent undrained soil, Ocean Engineering, 38(7): 943-953.

165. Zhu, H. and M. F. Randolph (2010), Large deformation finite element analysis of submarine landslide interaction with embedded pipelines, International Journal for Geomechanics, 10(4): 145-152.


Key papers

Low, H..E., T. Lunne, K.H. Andersen, M.A. Sjursen, M.A., X. Li and M.F. Randolph. (2010). Estimation of intact and remoulded undrained shear strength from penetration tests in soft clays. Géotechnique, 60(11), 843-859.

Difficulties in obtaining high quality soil samples from deep water sites have necessitated increasing reliance on piezocone, T-bar and ball penetration tests to determine soil properties for design purposes. This paper reports the results of an international collaborative project in which a worldwide, high quality database of lightly overconsolidated clays was assembled and used to evaluate resistance factors for the estimation of intact and remoulded undrained shear strength from the penetration resistance of each device. The derived factors were then compared with existing theoretical

solutions to evaluate the influence of particular soil characteristics. The overall statistics showed similar levels of variability of the resistance factors, with low coefficients of variation, for all three types of penetrometer. However, correlations of the resistance factors with specific soil characteristics indicated that the resistance factors for the piezocone were more influenced by soil stiffness, or rigidity index, than for the T-bar and ball, while the effect of strength anisotropy was only apparent in respect of resistance factors for the T-bar and ball relative to shear strengths measured in triaxial

compression. In the correlation between the remoulded penetration resistance and remoulded strength, the resistance factors for remoulded strength were found higher than those for intact strength and with slight tendency to increase with increasing strength sensitivity but insensitive to soil index properties. Based on an assessment of the influence of various soil characteristics, resistance factors are recommended for the estimation of intact and remoulded undrained shear strength from the penetration resistances of each device for soil with strength sensitivity less than six.

0 500 1000 1500 2000

qnet (kPa)

40

35

30

25

20

15

10

5

0

Dep

th (m

)

Chinguetti

Norwegian Sea

Laminaria

Ariake

0 500 1000 1500 2000

qT-bar (kPa)

Chinguetti

Laminaria

0 500 1000 1500 2000

qball (kPa)

OnsøyBurswoodChinguettiAriakeGOG 1GOG 2GOG 3GOG 4GOG 5GOG 6LaminariaNorwegian Sea

Chinguetti

Burswood

)c( )b( )a(

(a) Profiles of qnet (b) profiles of qt-bar (c) profiles of qball

(a) Comparison between qt-bar/qt-bar,rem and strength sensitivity. (b) Comparison between qball/qball,rem and strength sensitivity.

0

2

4

6

8

10

12

( )( )( )( )

( )( )( )( )

( )

( ) ( )

( )( )

( )Yafrate and DeJong (2006)

0 2 4 6 8 10 12St

0

2

4

6

8

10

12

q T-b

ar/q

T-b

ar,r

emq ba

ll/q

ball

,rem

Yafrate and DeJong (2006)

OnsøyBurswoodNorwegian SeaChinguettiBurswood 1g model testGOG 1 1g model test

35

Key papers

Pipelines are frequently subjected to active loading from slide events, both on land and in the offshore environment. Whether the pipeline is initially buried or lying close to the surface, and whether it crosses the unstable region or lies in the path of debris originating from further away, the main principles are unchanged. The pipeline will be subjected to active loading over some defined length, related to the width of the slide, and as it deforms will be restrained by transverse and longitudinal resistance in adjacent passive zones. Ultimately, the pipeline may come to a stable deformed shape where continued active loading from

the slide is equilibrated by membrane tension in the pipeline in addition to the passive resistance. Various authors have explored this problem, and these principles are well established. However, to date, no attempt has been made to develop a standard set of parametric solutions, which is the purpose of the current paper. Both analytical and numerical solutions of the problem have been developed, initially for slides acting normal to the pipeline but later extended to general conditions with the slide impacting the pipeline at some angle. It is shown that analytical solutions based on certain idealisations maintain their

accuracy over a wide parameter range, and the net effect of the slide in terms of stresses induced in the pipe wall and maximum displacement of the pipeline may be captured in appropriate dimensionless groups. Design charts are presented for slide widths of up to 1000 times the pipeline diameter, for a practical range of other parameters such as the ratios of passive normal and frictional resistance to the active loading. Although the solutions are limited by some of the idealisations, they should provide a useful starting point in design, providing a framework for more detailed numerical analysis for the particular governing conditions.

Randolph, M. F., D. Seo and D.J. White (2010), Parametric solutions for slide impact on pipelines, Journal of Geotechnical & Geoenvironmental Engineering, 136(7): 940-949.

effect of slide loading and width on maximum pipeline strains Variation of maximum combined strain with slide loading

0.00001

0.0001

0.001

0.01

10 100 1000 10000Normalized debris flow width, B/D

Com

pute

d st

rain

, /E

Bending

Tension

CombinedqB/EA =

0.0010.0005

0.00020.00010.000050.00002

p/q = f/p = 0.50.0001

0.001

0.01

0.00001 0.0001 0.001 0.01Slide loading, qB/EA

Com

pute

d str

ain,

/E

p/q = 4, f/p =1p/q = 0.5, f/p = 1p/q = 0.5, f/p = 0.5p/q = 0.5, f/p = 0.25p/q = 0.05, f/p = 0.25

B/D = 100 B/D = 10,000

Note, order of curves is from centre outwards for the two B/D values, according to the legend


Hodder, M. S. and M. J. Cassidy (2010), A plasticity model for predicting the vertical and lateral behaviour of pipelines in clay soils, Geotechnique, 60(4): 247–263.

Key papers

uwa drum centrifuge used for pipeline testing

A complete theoretical model for predicting the undrained behaviour of a rigid pipe in clay soils when subjected to combined vertical and horizontal loading is described. Physical modelling of a pipe on soft, lightly overconsolidated kaolin clay was conducted, with the experimental test program specifically designed to establish the model parameters.

The testing was conducted within The University of Western Australia’s geotechnical drum centrifuge using an element of pipe 10mm in diameter, 50mm in length and at an acceleration 50 times the Earth’s gravity. The model presented is expressed by the force resultants on the pipe and the corresponding displacements and allows predictions of response

to be made for various vertical and horizontal load or displacement combinations. However, it is limited to monotonic loading and relatively small displacements. The model is verified in this paper by retrospectively simulating a selection of combined loading tests and comparing the output with the experimentally recorded results

37

Tian, Y. and M. J. Cassidy (2008), Modelling of pipe-soil interaction and its application in numerical simulation, International Journal of Geomechanics, 8(4): 213-229.

Key papers

Footing response of 30-m span

This paper presents three plasticity models that can be applied to numerically simulate pipe-soil interaction. They can be applied individually to evaluate the force-displacement response of a small plane-strain pipe section or in combination to simulate a long pipeline system. In the latter, numerous pipe-soil elements are attached to structural finite-elements, each simulating localised foundation restraint along the pipeline. The three models are increasing in sophistication, mainly due to the manner in which they account

for the behaviour within an allowable combined loading surface. The first is based on traditional strain-hardening plasticity theory and therefore assumes purely elastic response inside a single expandable yield-surface. The second allows some plasticity due to the use of a bounding surface, and the third accounts for kinematic hardening through the introduction of a second smaller surface. The models are detailed in this paper, allowing for simple numerical implementation. Importantly, they are incorporated within the structural analysis of a pipeline

and their potential to investigate generic pipeline system behaviour is demonstrated. The applicability of the three models is interpreted theoretically and their differences shown through application for (i) a one pipe-soil interaction element, and along (ii) a 100m segment of pipeline. The latter shows the practical application of these models to offshore pipeline engineering examples, with the influence of a free span behaviour investigated. The ability to model complex cyclic loading is also shown.


Liu, H.B. and X.L. Zhao (2011), Predictions of fatigue life of steel connections under combined actions using boundary element method, The 21st International Offshore and Polar Engineering Conference, Maui, Hawaii, USA, 19-24 June, Volume 4, pp. 276-281

Key papers

The fatigue life of girth weld is always an important issue for subsea pipelines. In this paper the method of numerical modelling was used to study the fatigue behaviours of subsea pipeline steel connections. The analytical models were established using the software of BEASY, which is developed on the basis of the

boundary element method of analysis. Combined forces were applied in these models: constant amplitude cyclic mode I load and perpendicular static load. The numerical results were compared with the corresponding experimental results and good agreements were achieved. Their fatigue behaviours

were described clearly by the stress intensity factors near crack-tip, the crack propagation rates and the fatigue lives. The effect of perpendicular static load, stress ratio and stress range on fatigue behaviours were evaluated through parametric study.

Pipeline displacement after 3 hrs hydrodynamic loads

Hand pump

Hydraulic to apply hoop force

Loading frame

F1

F1

FhFh

Footing response of 30-m span

39

Zhao, M. and L. Cheng (2010), Numerical investigation of local scour below a vibrating pipeline under steady currents, Coastal Engineering, 57: 397-406.

Key papers

Local scour below a vibrating pipeline under steady current is investigated by a finite element numerical model. The flow, sediment transport and pipeline response are coupled in the numerical model. The numerical results of scour depths and pipeline vibration amplitudes are compared with measured data available in literature. Good agreement is obtained. It is found that pipeline

vibrations cause increases of scour depth below the pipeline. The scour pit underneath a two-degree-of-freedom vibrating pipeline is deeper than that under a pipeline vibrating only in the transverse flow direction. The effects of water depth are also investigated. The present numerical result shows that water depth has weak effect on the scour depth. However it does affect the time

scale of the scour. The shallower the water depth is, the less time it requires to reaches the equilibrium state of scour. It is found that the vibration forces vortices to be shed from the bottom side of the pipeline. Then vortex shedding around a vibrating pipeline is closer to the seabed than vortex shedding around a fixed pipeline. This contributes to the increase of the scour depth.

mini –tube facility: 0.25m x 0.25m test section area

time development of scour below a pipeline


Albermani, F., H. Khalilpasha and H. Karampour (2011), Propagation buckling in subsea pipelines, Engineering Structures, 33(9): 2547-2533

Key papers

The paper investigates buckle propagation in deep subsea pipelines. Experimental results using ring squash tests and hyperbaric chamber tests are presented and compared with a modified analytical solution and with

numerical results using finite element analysis. The experimental investigation was conducted using commercial aluminium pipes with diameter-to-thickness (D/t) ratio in the range of 20-48. In contrast to conventional cylindrical

pipe, a faceted cylindrical geometry is also investigated. Preliminary analysis of a faceted pipe shows that a substantial increase in buckling capacity can be achieved for the same D/t ratio.

ring squash test rSt

(a) (b)

41

Senthilkumar, M. P. Rajeev, J. Kodikara, and N. I. Thusyanthan, (2011). Laboratory modelling of pipe-clay seabed interaction in axial direction, The 21st International Offshore and Polar Engineering Conference, Maui, Hawaii, USA, 19-24 June.

Key papers

The current trend of bottom embedding of offshore petroleum pipelines is increasingly being challenged by the expansion of the pipeline at elevated operating conditions of temperature and pressure. For simplicity, the expansion challenges could be classified into

axial walking and lateral buckling, relevant to the axial and lateral components of interaction. This paper summaries current knowledge on the axial resistance of surface laid pipes, in general, the pipe-soil interaction in axial direction. The experimental

works obtained from literature are detailed and modelling techniques are reviewed. Finally, the development of the Monash Advance Pipe testing System (MAPS) for further investigating axial response is explained and the testing methods are discussed.

monash advanced Pipe testing System (maPS)

monash advanced Pipe testing System (maPS) in action


Wang, D., D.J. White and M.F. Randolph. (2010), Large deformation finite element analysis of pipe penetration and large-amplitude lateral displacement, Canadian Geotechnical Journal, 47(8): 842-856.

Key papers

Seabed pipelines must be designed to accommodate thermal expansion – which is commonly achieved through controlled lateral buckling – and to resist damage from submarine slides. In both cases, the pipe moves laterally by a significant distance and the overall pipeline response is strongly influenced by the lateral pipe-soil resistance. This resistance is affected both by the soil conditions and also the weight of the pipe, since the longitudinal flexibility allows the pipe to move vertically while being pushed or dragged laterally. In this paper, the process of pipe penetration and lateral displacement is investigated

using a large deformation finite element (LDFE) method, with a strain-softening, rate-dependent soil model being incorporated. The calculated soil flow mechanisms, pipe resistances and trajectories from the LDFE analyses agree well with upper bound plasticity solutions and centrifuge test data. It is found that the lateral resistance is strongly influenced by soil heave during penetration and the berm formed ahead of the pipe during lateral pipe displacement. Two distinct modes of behaviour are evident, depending on the weight of the pipe relative to

the soil strength. For ‘light’ pipes, the pipe rises to the soil surface and the soil failure mechanism involves sliding at the base of the berm. In contrast, ‘heavy’ pipes dive downwards and a deep shearing zone is mobilised, expanding with continuing lateral movement. The different responses are reconciled by defining an ‘effective embedment’ that includes the effect of the soil berm or wall ahead of the pipe. The relationship between normalised lateral resistance and effective embedment is well fitted using a power law, regardless of the pipe weight.

equivalent plastic strain around pipe after vertical penetration (w/D = 0.45)

Soil flow mechanisms for a heavy pipe (r = 1.25)

x/D

z/D

-1.5 -1 -0.5 0 0.5 1 1.5

-1

-0.5

0

0.5

1

1.5

u/D=0.01

(a)

x/D

z/D

-2.5 -2 -1.5 -1 -0.5 0 0.5

-1

-0.5

0

0.5

1

1.5

u/D=0.5

(b)

x/D

z/D

-3 -2.5 -2 -1.5 -1 -0.5 0

-1.5

-1

-0.5

0

0.5

1

u/D=1.0

(c)

x/D

z/D

-4.5 -4 -3.5 -3 -2.5 -2 -1.5

-1.5

-1

-0.5

0

0.5

1

u/D=2.0

(d)

43

Boylan, N., C. Gaudin, D.J. White and M.F. Randolph (2010), Modelling of submarine slides in the geotechnical centrifuge, 7th International Conference on Physical Modelling in Geotechnics (ICPMG 2010), Zurich, Switzerland CD:1095-1100.

Key papers

The depletion of near shore hydrocarbon resources has led to a move to exploration and production in deep and ultra-deep waters. This shift into deeper waters requires increased reliance on sub-sea installations and pipelines that can extend to more than 500km from shore, often across areas of changing seabed morphology and continental shelves. The viability of these developments is increasingly

dependent on the security of the installations and tie-backs to shore, which are susceptible to geohazards such as submarine slides. The Centre for Offshore Foundation Systems (COFS) has initiated research to investigate the impact of submarine slides on offshore pipelines. As part of this project, a facility has been developed to model submarine slides in the geotechnical drum centrifuge at the University of

Western Australia. This facility uses the long, narrow channel of the drum centrifuge to model the run-out of submarine slides that are triggered from an intact block of clay, along a model seabed. This paper describes the development of the apparatus to trigger the slides in the drum centrifuge and presents some results from the first tests conducted in the facility.

Slide triggering device

Sliding door Paddle

intact block of clay Counter mass

Legend

Cross-section of drum centrifuge equipment for slide modelling

Slide box CLD gantry Slide run-out


Baldock, T. E. and J. K. Seelam (2009), Numerical and physical modelling of tsunami run-up and impact on subsea pipelines, 1st Annual Society for Underwater Technology Subsea Technical Conference (SUT), Perth.

Key papers

This paper presents initial results from experimental and numerical modelling of tsunami wave propagation over the continental slope and near shore region. The paper considers the potential impacts of tsunami waves on subsea pipelines, which may be indirect i.e. the triggering of submarine landslides or turbidity currents. The project will also consider how the complex bathymetry around pipelines may change the fluid loading, and it will also examine the potential loads induced by internal waves. The modelling encompasses both overland flow processes and the seabed pressures and shear stresses induced by tsunami waves. Likely conditions

on the continental shelf and on the continental slope are also examined.

The experimental measurements include data covering non-breaking and breaking tsunami-type waves obtained from the large-scale Tsunami Wave Basin at Oregon State University. Initial experimental measurements of sea bed pressures and bed shear stresses will be presented from the University of Queensland tsunami wave flume, which will subsequently be used to investigate the potential for tsunami-induced liquefaction of the sea bed around pipelines and the potential for tsunami to trigger submarine landslides. The paper provides an overview and initial

results of the experiments which aim to simulate conditions corresponding to the continental shelf slope and particularly the near shore zone, where tsunami breaking may generate high horizontal pressure gradients over large areas of the seabed. Novel shear cell measurements will be made to investigate the relative contribution of shear stress and pressure gradients to submarine slide initiation. Tsunami kinematics within submarine canyons may amplify the tsunami motion and flow velocities and is also of concern. The experimental results will be used to further refine numerical modelling of tsunami and to develop models.

oSu tsunami wave basin

45

Pusey, G. and A. Duncan (2009), A preliminary study of underwater acoustic communications over horizontal ranges, 1st Annual Society for Underwater Technology Subsea Technical Conference (SUT) Perth, CD.

Key papers

Difficulties in subsea data telemetry stem from issues to do with electromagnetic wave penetration and procedures involved in deploying and maintaining cabled solutions. While acoustic modems are increasingly useful in many

applications, communications over a large horizontal range are subject to many complications. This study investigates the various mechanisms affecting acoustic propagation, specifically those important for data

transmission over long ranges. This is followed by preliminary results from propagation models and trials off the coast of Western Australia.

Summary of deployment results showing modem performance over range (a) and the corresponding signal strength data detected by the ambient noise recorder (b).

(a) (b)


Awards

Postgraduate student awards:Benthic Scholarship: Han Eng Low • Hamed Mahmoodzadeh Poornaki

Sut Scholarship: Bassem Youssef

ausaid Scholarship: Siti Fatin Mohd Razali

Pipeline industry awards:

australian Gas innovation award Commendation

Bassem Youssef received the Australian Gas Innovation Award Commendation. He was recognised for his unique pipeline on-bottom stability simulation program, developed as part of his PhD study. This provides pipeline engineers with a reliable and accurate pipeline design tool capable of a 3D simulation of offshore pipelines under the action of wave and current loading. Bassem was supervised by Mark Cassidy and Yinghui Tian.

> Bassem Youssef

47

Researcher awards:whitfield Scholarship: Hongjie Zhou

australian academy of Science’s anton hales medal: David White

arC Future Fellowships: David White • Mark Cassidy

2011 e.h. Davis lecturer: Mark Cassidy

2011 wa young scientist of the year: David White

Pipeline industry awards:

industry innovation and technology prize and innovation and Development category of the 2012 wa engineering excellence awards

Cluster Chief Investigators Liang Cheng and David White, along with Scott Draper and Hongwei An won the Innovation and Development category of the 2012 WA Engineering Excellence Awards for the O-Tube Program, which simulates the effects of cyclone on subsea pipelines. The O-Tube also won the Subsea Energy Australia Industry Innovation and Technology Award. The research is crucial for Australia’s massive oil and gas industry, which plans to install an estimated 3000km of offshore pipelines worth more than $15 billion over the next 10 years.

> David white with the beam centrifuge


Keynote presentations, invited lectures and papers

Boylan, N. P. and D. J. White (2010). Geotechnical frontiers in offshore engineering – invited keynote lecture. International Symposium on Recent Advances and Technologies in Coastal Development, Tokyo, Japan, CD: 18 pages.

Cassidy, M.J. (2009). Engineering for a new generation of offshore production. ATSE Focus. Vol. 154, Australian Academy of Technological Sciences and Engineering, pp. 21-22.

Cassidy, M.J. (2009). Foundations for Australia’s offshore oil and gas installations, WA Chapter of the Australian Academy of Technological Sciences and Engineering, 10 June 2009.

Cassidy, M.J. and Y. Tian (2011). Development and application of models for the stability analysis of Australia’s offshore pipelines. Proc. 2011 Symposium on Coastal and Marine Geotechnics: Foundations for trade, 15th Annual Symposium of the Australian Geomechanics Society, Sydney, Australia.

Hao H. (2009). SHM research in UWA, Guangzhou University, China, 2009.

Randolph, M.F., C. Gaudin, S. Gourvenec, D.J. White, N. Boylan and M.J. Cassidy (2011), Recent advances in offshore geotechnics for deepwater oil and gas developments, Ocean Engineering.

Randolph, M. F. and D. J. White (2008), Offshore foundation design – a moving target. Keynote paper, 2nd International Conference on Foundations (ICOF), Bracknell, UK, 27-59.

Randolph, M. F., D. Wang, H. Zhou, M.S. Hossain and Y. Hu (2008), Large deformation finite element analysis for offshore applications, 12th International Conference of International Association for Computer Methods and Advances in Geomechanics (IACMAG), Goa, India, CD: 3307-3318.

White, D.J. (2008). Geotechnical design of seabed pipelines, European Symposium on Centrifuge Modelling, London, May 2008.

White, D.J. (2009). Recent advances in pipeline geotechnics made through centrifuge modelling at UWA, Deltares, The Netherlands, December 2009.

White, D.J. and C. Gaudin (2009). Physical modelling techniques developed within the Cluster and the resulting advances in pipeline analysis techniques, International Workshop on Geotechnical Modelling, Tongji University, China, November 2009.

White, D. J. and D. N. Cathie (2011). Geotechnics for subsea pipelines – a keynote lecture. 2nd International Symposium on Frontiers in Offshore Geotechnics, Perth, Australia, n/a: 87-123.

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Hosting the Second International Symposium on Frontiers in Offshore Geotechnics Pipeline engineering and the research of the Subsea Pipeline Collaboration Cluster was highlighted at the Second International Symposium on Frontiers in Offshore Geotechnics (ISFOG), hosted by the Centre of Foundation Systems at the University of Western Australia, Perth, between 8 and 10 November 2010.

The ISFOG symposium provided a platform for academics and practitioners to discuss and exchange ideas to address the emerging challenges in offshore geotechnical engineering and showcase state-of-the-art offshore geotechnics.

ISFOG 2010 was opened by Ann Pickard, the Country Chair of Shell in Australia and Executive Vice President of Shell Upstream Australia.

The symposium attracted 306 delegates from 24 countries representing industry and academia.

The technical themes of the symposium were selected to reflect the key stages of an offshore project. They ranged from assessing offshore geohazards with state-of-the-art geophysics and in situ geotechnical testing techniques, through to design considerations for foundation solutions and pipelines, culminating in key considerations involving design risk.

Professor David White delivered the keynote lecture, and international practitioners and academics presented 14 papers on pipeline engineering. These can be found in the proceedings.

ann Pickard, Country Chair of Shell, at the opening of iSFoG 2010 with mark Cassidy

Christophe Gaudin giving a tour of the beam centrifuge during iSFoG2010 iSFoG2010 proceedings


The Subsea Pipeline Collaboration Cluster combined the capabilities of:

◆ The University of Western Australia

◆ Curtin University of Technology

◆ The University of Queensland, Brisbane

◆ Monash University, Melbourne, Victoria

◆ The University of Sydney

◆ Flinders University, Adelaide

◆ CSIRO Wealth from Oceans Flagship.

The

part

ners

51

The Flagship Collaboration Fund enables the skills of the wider Australian research community to be applied to the major national challenges targeted by the CSIRO’s National Research Flagship Program.

As part of the $305 million provided over seven years by the Australian Government to the National Research Flagships, $97 million was allocated specifically to enhance collaboration between the CSIRO, Australian universities and other publicly funded research agencies.

The Australian Government’s budget announcement in 2007 provided additional resources for the fund. The Subsea Pipeline Collaboration Cluster contributes to the Wealth from Oceans Flagship. The program aims to work with industry to develop the science and technology to unlock new opportunities in the exploration and development of Australia’s offshore hydrocarbon resources. The cluster consisted of a $3.6 million grant through the Flagship Collaboration Fund and in-kind contributions totalling $7.4 million from the participating universities.

Flag

ship

Col

labo

rati

on F

und

For Further inFormation

Flagship Collaboration Cluster leaderWinthrop Professor Mark Cassidy Director – Centre for Offshore Foundation Systems, University of Western Australia M053 35 Stirling Highway Crawley WA 6009 t +61 8 6488 1142 f +61 8 6488 1104 e [email protected]

CSiroIan Cresswell Science Director, Wealth from Oceans National Research Flagship, CSIRO GPO Box 1538 Hobart TAS 7001 t +61 3 6232 5213 f +61 3 6232 5125 e [email protected]

ContaCt uSt 1300 363 400 +61 3 9545 2176 e [email protected] w www.csiro.au

Your CSiroAustralia is founding its future on science and innovation. Its national science agency, CSIRO, is a powerhouse of ideas, technologies and skills for building prosperity, growth, health and sustainability. It serves governments, industries, business and communities across the nation.

subsea pipelines collaboration cluster

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