the university of western australia · tarpaulin bellowing takes place when it is windy. it is...

THE UNIVERSITY OF WESTERN AUSTRALIA

SCHOOL OF CIVIL AND RESOURCE ENGINEERING

FINAL YEAR PROJECTS 2010 1. Attached is a list of projects that are being offered by staff members in the School, the Centre

for Offshore Foundation Systems (COFS) and the Australian Centre for Geomechanics (ACG). Students may propose other topics (for example with an external company or government agency), in consultation with any staff member. By the end of the third week of 1st Semester (by the end of the third week of 2nd Semester if a Mid Year enrolment) it is essential that each student shall have agreed on a topic with a supervisor and have submitted the title to the Head of School.

2. Each Project unit will have a 12 point weighting out of about 48 points for the year. Since this

is a unit equivalent to a quarter of the total year’s work, each student is expected to devote at least the equivalent amount of time to the project throughout the whole year. You cannot expect to get a high grade in your Project unless you put the appropriate effort (and time commitment) into this unit.

3. Each project will be broad enough to be completed at a high enough level that can justify the

award of Honours. Project reports (theses) will be graded on a continuous scale. At the end of the year, the performance in the Project, combined with the performance in the coursework component over the four years of the degree will be used to assign results on a continuous scale, from 1st Class Honours, through 2A and 2B Honours, to Pass. Students should refer to the Final Year Handbook for details.

4. Students are encouraged to choose projects that are consistent with their goals for

employment and the general thrust of their choice of other options in final year. The Head of School, or other supervisors, should be consulted about the wisdom of the choice being made, particularly with regard to appropriateness of the choice in relation to the other final year options chosen.

5. At the start of 1st semester, a Project Booklet, giving details of various aspects of the projects,

will be distributed. Briefly, the assessable components of the project are: • a progress report, submitted during 1st semester; • a short summary paper submitted prior to the “Final Year Project Symposium”, held in 2nd

semester; • an oral presentation of your project made at the above Symposium in front of fellow

students, staff, and industry representatives; and • the final Project Report (Thesis), submitted at the end of 2nd semester.

Liang Cheng Head of School 3 March 2010

List of Supervisors

Liang Cheng 1

James Doherty 3

Britta Bienen (COFS) 6

Dave White (COFS) 7

Hong Hao 8

Yuxia Hu 12

Kenneth Kavanagh 15

Arcady Dyskin 18

Susan Gourvenec (COFS) 28

Ming Zhao 31

Andy Fourie 32

Mehrdad Kimiaei (COFS) 37

Noel Boylan (COFS) 39

Hang Thu Vu 40

Richard Durham 43

Tongming Zhou 45

Daniela Ciancio 48

Jeremy Leggoe (CEED Project) 52

Barry Lehane 53

Chari Pattiaratchi (SESE and UWA Oceans Institute) 55

School of Civil & Resource Engineering 1

Supervisor: Professor Liang Cheng [email protected]

1. Onset of scour below a partially embedded pipeline

When a partially embedded pipeline is subjected to an environmental flow (induced by waves or tidal currents), the flow over the pipeline produces a large pressure difference between the upstream and downstream sides of the pipeline. The pressure difference over the pipeline then induces a seepage flow in the soil underlying the pipeline. The onset condition for scour is considered to occur when the seepage flow pressure gradient at any point on the seabed exceeds the floatation gradient of the soil.

This project aims to investigate onset of scour below a partially embedded pipeline under combined wave and current conditions. An existing numerical model that was developed at UWA will be used to carry out this work. The critical embedment depth for onset of scour under different wave and current combinations will be quantified.

2. Seabed morphology around a partially buried pipeline Subsea pipelines laid directly on erodible seabed are subjected to natural burial through a number of physical processes such as installation stresses and local scour. Burial of pipelines is beneficial for the stability of the pipelines. However pipeline burial depth may undergo significant changes during the passage of a storm event. The burial depth change during a storm affects pipeline stability. Since such changes often occur during storm period, it is very difficult to monitor such changes in-situ.

This project aims to simulate seabed morphology around a partially buried pipeline using a state of art scour package developed at UWA. The effect of initial burial depth on seabed morphology change and hydrodynamic forces will be investigated under a range of flow conditions. It is expected that improved understanding gained through this project will benefit pipeline design practice.

3. Local scour around gravity anchors In recent years, gravity anchors (GAs) have become a preferred option as secondary stabilization of large diameter pipelines installed in Australian waters. Gas are typically arch-shaped concrete blocks. They are often fabricated from pre-cast concrete. GAs are installed astride a pipeline or a pipeline bundle as shown in Figure 1. Typical dimensions of a GA are approximately 3.5 m in depth (along pipeline direction), 6 m in width (perpendicular to pipeline) and 3 m in height. They weigh around 40 to 50 tonnes in air or 25 to 35 tonnes in water. Under normal operating conditions, GAs are separated from the pipeline. GAs are engaged to provide additional resistance to pipeline movements only if the pipeline moves sideways under extreme loading. Pipelines are not designed to carry any load directly or indirectly from GAs.

The presence of a GA over a pipeline disturbs flow patterns in the immediate neighbourhood of the combined anchor-pipeline system. This leads to an increase in local sediment transport capacity of the flow and consequently scour of sediments around the GA. Scour can undermine the stability of GAs. Once a gravity anchor losses its stability, it posses significant risk to the safety of the pipeline. For example, the pipeline can be damaged by excessive loading exerted by the weight of the gravity anchor if the gravity anchor

Figure 1 A Typical GA-Pipeline

mailto:[email protected]


settled on to the pipeline. To prevent this from happening, scour protection measures around GAs are almost inevitable. The choice of a different scour protection system around the GA-pipeline system can have significant impacts on the engineering costs of the project.

The overall objectives of this project are to investigate cost-effective scour protection measures and to develop practical scour protection design guidelines, based on the understanding of scour and flow mechanisms around GA-pipeline systems. Specifically we will

1. carry out physical model tests to investigate the dependence of local scour depths, scour extents and scour rates on various flow and sediment parameters under steady currents , waves and combined waves and currents conditions;

2. Investigate the effectiveness and costs of various scour protection measures for GA-pipeline systems;

The tests will be carried out in the only O-tube facility in the world located at UWA. Two motivated students are required to carry out the project. One student will focus on local scour mechanisms and the other student will investigate cost-effective scour protection measures.

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4. Experimental investigation of tarpaulin bellowing under wind loading Tarpaulin is widely used to protect grains from being wet in grain storage bunkers. Tarpaulin bellowing takes place when it is windy. It is speculated that tarpaulin bellowing has negative impacts on the life span of a tarpaulin and positive effects on fumigants transport within the grain volume during fumigation processes. However the current understanding of tarpaulin bellowing is not adequate for good industry practices.

This project aims to carry out a number of wind tunnel tests to measure tarpaulin responses under different ambient wind conditions and its effect on fumigant distribution within grain storages. It is expected improved understanding of tarpaulin bellowing will have positive impacts on current industry practices.

5. Numerical modeling of three-dimensional flow around an embedded pipeline in a water flume

Flume tests have been the most effective way to understand flow/pipeline/seabed interaction problems. Due the limited width of most available flumes, tests are often conducted in a two dimensional manner. The common practice is to place the pipeline on a sand bed over the entire width of the flume in the perpendicular direction to the flow. Experimental measurements are often carried out along the central line of the flume. Such a practice is based on the assumption that flow remains two dimensional along the central line of the flume and will not be affected by the three dimensional flow at the junctions of pipeline ends with the flume walls. It is discovered in a number of local scour experiments that local scour is often initiated from the ends of the pipeline and propagates towards the center of the pipeline. This has been referred to as “end effects”. It is believed that the “end effects” is caused by the three dimensional flow at the ends of the pipeline. However this has not been quantified previously.

This project aims to investigate “end effects” using a state of art computational fluid dynamic (CFD) model developed at UWA. The local flow structure and seabed shear stresses at the ends of the pipeline will be quantified using the CFD model. The minimum flume width required for this type of tests will be determined under different test conditions.


Supervisor: Dr. James Doherty [email protected]

1. Earthquake Engineering: Real versus Spectral Modified Time-Histories.

(Suitable for BE) For large projects (offshore oil and gas platforms, or major onshore infrastructure), seismic hazard assessments are often carried out by seismologists, who specify the design earthquake motion in terms of magnitude, peak ground acceleration, epicentral distance, fault type and response spectra. The engineer must then convert this information into usable design loads. In recent times, it has become common practice to perform analysis (in time or frequency domain) using recordings of real earthquake motion (earthquake time-history). However, the response spectra specified by seismologists is generally much broader than real earthquake motion. Therefore, it is not possible for the engineer to satisfy design earthquake motion with a single earthquake time-history, so the analysis must be repeated with several different time-histories which in combination match or envelope the design/target response spectra. This has led to the use of spectral modified time-histories, where, as the name suggests, real earthquake motion is modified to match the boarder target response spectra. The use of spectral modified time-histories may produce unrealistic results for two reasons. Firstly, for an otherwise equivalent earthquake (magnitude, peak ground acceleration, epicentral distance) spectral modified time histories have significantly more energy. This may unrealistically penalise earth structures, such retaining walls, embankments and slopes. Secondly, structures with two or more natural periods of motion in the range of the target spectra may be more severely affected by the artificial motion. In this project, the response of various structures subject to real earthquake motion and spectral modified motion will be compared. It is expected analysis will be conducted using either or all of the following software packages (Plaxis, Abaqus, Shake) 2. Finite Element Analysis of Excavations with Adjacent Surcharge Loading (Suitable for BE) Excavations or land-backed wharves are commonly supported by sheet pile or diaphragm walls. The finite element method is now commonly used in the design, and normally there is a requirement to allow for surcharge loads applied adjacent to the walls. These loads may be caused by heavy vehicle or equipment (used during construction) or permanent structures. Due to time constraints and available computing power, the analysis is invariably carried out assuming plane strain conditions. The plane strain assumption is often reasonable for the geometry of the wall, but not for the geometry of the surcharge load. The aim of this project is to produce a method for converting actual loaded areas into equivalent loads suitable for plane strain analysis. The project will involve parametric studies of excavations using two and three-dimensional versions Plaxis finite element software.



3. Soil Parameter Selection using Numerical Optimisation (Suitable for Masters and BE) An ability to predict the soil and structural deformation is critical to the cost effective construction of almost all civil and industrial infrastructure. However, current methods are still unreliable. The finite element method provides the most versatile approach to predict soil and structure deformations. However, the accuracy of the prediction largely depends on the accuracy of the soil constitutive model (the model representing the soil behaviour). Due to the complicated way in which soil behaves, soil constitutive models must either be simplified to the point where their predicative capability is very limited, or they remain so complex that for practical engineering problems it is difficult (if not impossible) to accurately determine the constitutive model parameters. This project will explore the use of mathematical optimisation techniques to calibrate constitutive models based on the stress-strain/load-displacement response measured from both laboratory and in-situ tests, including triaxial, pressuremeter and foundation load tests. Finite element models representing each test will then be used to calculate the constitutive model’s response with a given set of parameters. Individual norms will then be calculated for each test, which measure difference between the actual and calculated load-displacement response. These individual norms are combined to form a global norm for all tests. Direct search methods are then employed to vary the constitutive model parameters, between specified upper and lower bounds, in order to minimise the global norm. Methods for forming both individual and global norms will be investigated, and the performance of different search methods will compared by considering example problems involving both uniform and layered soil profiles. The project will involve programming in MATLAB, as well as using Abaqus finite element software. 4. Development and Documentation of a MATLAB Finite Element Library (Suitable for Masters and BE) A “Library” of MATLAB functions is being developed to perform non-linear finite element analysis for geotechnical problem. Many functions have already been developed. However, a number of these functions require improvement in their performance and documentation and many additional functions are required. This project involves improving and documenting existing MATLAB functions and developing new functions. Students should have a strong interest in programming and numerical methods. 5. Effective Stress versus Total stress analysis of undrained problems in geotechnical engineering Several different options are available for modelling undrained behaviour in finite element analysis. If they are not properly understood, results may be grossly incorrect, leading to catastrophic collapse. This was highlighted by the recent collapse of a major excavation in Singapore. The aim of this project is to simulate undrained excavations in several different ways, compare the results and make recommendations regarding the suitability of each approach.


6. The Simple Shear Test – a 3-D Finite Element Study (Co-Supervisor: Professor Martin Fahey)

The type of simple shear test carried out at UWA involves a cylindrical specimen, typically 40 to 100 mm in diameter, and a height of the order of 30% of the diameter. The sample is enclosed in a membrane between top and bottom caps, within a pressurised cell, just as in a triaxial test setup. The top cap is fixed against rotation, and the bottom cap sits on roller bearings, and is driven horizontally via a motor drive. Vertical load is likewise applied via a motor drive. Specimens are consolidated by increasing the vertical load (stress) and cell pressure independently, generally with an elevated back pressure to ensure saturation. An undrained shearing test is carried out by displacing the bottom drive horizontally, while maintaining a constant height and zero volume change. With no means of generating complementary shear stresses on the vertical faces of the sample, the mode of shearing cannot be true ‘simple shear’. In fact, the stress state in the sample is quite complicated, and this leads to some uncertainty in how to interpret the test results. This project will involve a finite element study of the UWA simple shear test, carried out using the 3-D version of the program Plaxis. Soil models used include an elastic-plastic (Tresca) model, an elastic Mohr Coulomb model, and a soft-soil hardening model (a Cam Clay type model). The results will be used to show the strengths and limitations of the UWA simple shear test, and indicate how the test results should be interpreted.


Supervisor: Dr. Britta Bienen [email protected]

1. Experimental investigation of the effectiveness of winged piles in carbonate soil (suitable for BE)

(Co-supervisor: Prof. Mark Randolph) Many applications offshore transfer large horizontal loads to their pile foundations, for instance offshore wind farms or the anchorages of floating offshore facilities (FPSOs). In both applications large horizontal loads and moments are induced compared to the vertical loads acting on the pile. As the soils at shallow depth below the mudline often provide less lateral resistance compared to those at greater depths any additional lateral capacity of the anchor pile that can be mobilized has the potential to shorten the required anchor pile length, which implies direct and indirect cost savings (less risk of pile refusal during driving, ability to use a smaller pile driving hammer). The issue is particularly relevant for the carbonate soils found on Australia's North West Shelf, which generate low lateral pile resistance. The concept of “wings” welded close to the pile head to increase the pile’s lateral capacity has recently been shown to be feasible and effective in siliceous sand. This project will investigate piles with wings in carbonate soils through experiments conducted in the geotechnical centrifuge. 2. Numerical modelling of the load-displacement response of circular shallow foundations on clay (suitable for FE)

(Co-supervisor: Dr Susan Gourvenec) The load-displacement behaviour of shallow foundations continues to be a topic of interest to the offshore industry. In the context of mobile offshore jack-up drilling rigs in particular there has been a number of experimental investigations aiming at the development of a model that can predict the non-linear footing load-displacement response. However, since only a limited number of loading combinations have been able to be investigated experimentally, it would be beneficial to complement the existing experimental data set numerically with the ultimate aim of establishing the footing model in all six degrees-of-freedom in three-dimensional space. This project could further investigate any difference in the shape and size of the combined VHM yield surface between a flat and a spudcan footing. The latter footing type has a conical base and is typically used for mobile offshore drilling rigs. The commercial finite element software Abaqus will be used for this project.


Supervisor: Dr. David White [email protected]

1. The interface shear strength of soils at very low effective stresses There will be more than 2000 km of pipeline installed on the seabed offshore Australia in the next 5 years. The axial resistance between the pipeline and the seabed controls the thermal expansion of the pipeline, and its stability against external loads. This is an experimental project aimed at measuring the interface shear strength of soil relevant to low effective stress applications such as pipelines. At very low stresses the friction angle of soil is higher than at the stress levels relevant to conventional geotechnical problems. There is also a transition in behaviour as the response at the interface changes from drained to undrained conditions as the velocity of movement increases. These two simple phenomena are poorly understood, and have not been quantified for soils found offshore Australia. A modified shear box has been fabricated and the project would involve tests using this device and investigating the strength of seabed soils at very low stress levels, beyond the range of previous experience. Measurements of the low-stress strength and the undrained-drained transition will be made, and distilled into a simple model. This model will be input into a simple analysis for the expansion of a pipeline, to illustrate the impact of the observed behaviour. The outcome of this project would be a better understanding of the axial pipe-soil response for Australian offshore soils.



Supervisor: Professor Hong Hao [email protected]

1. Effect of infilled wall on stiffness and lateral loading capacity of RC frame structures

(Suitable for both undergraduate and postgraduate students)

Although infilled walls in RC frame structures significantly affect the structural vibration properties and structural lateral load-carrying capacities, in most designs and analyses of structural frame structures, the infilled walls are usually either neglected or simplified as brace members. In this project, both numerical and experimental study will be carried out to more accurately predict the effect of infilled wall on structural stiffness and capacity. Two scaled single-storey frame models with or without masonry infilled wall will be built in laboratory. Push-over tests will be carried out to obtain the load-deflection curves of the two frames with or without infill wall. By comparing the push-over curves, the influence of the infilled wall on structural stiffness and capacity will be obtained. An idealized mechanism will be developed to effectively model the infilled wall. Numerical models will be developed to predict the dynamic responses of the frame structure with or without infilled wall to earthquake and impact loads. Student taking this project will work together with the student doing project 2 in designing and constructing the scaled models, and in doing the experimental tests. 2. Vibration test and condition monitoring of the frame structure with or without

masonry wall (Suitable for both undergraduate and postgraduate students) Vibration-based structural condition monitoring methods have been intensively researched. The reliability of these methods depends on accurate measurements of structural vibration properties and a high fidelity structure model usually based on finite element method. Often in practice, the inflled walls in a frame structure are neglected in to finite element modeling because they are considered as not load-carrying structural components. However, existence of infilled walls will greatly affect the structural vibration properties. If they are not properly modeled, they might lead to erroneous structural condition monitoring. In this project, two scaled RC frame structures, one with infilled masonry wall will be constructed in the laboratory. Vibration tests of the two models will be carried out progressively at different push-over levels to extract the vibration properties. The influence of infilled wall on frame vibration properties will be examined. Student taking this project will work together with the student doing project 1. 3. Effect of staircase on stiffness and lateral loading capacity of RC frame

structures (Suitable for undergraduate students) Staircase is not a load-carrying structural component therefore it is often neglected in structural analysis and design. After the 2008 Wenchuan earthquake in China, some researchers suggested to properly design the staircase and make it stronger than the



structure so that it can be used as an emergency shelter during earthquakes and other disaster. In this project, two simple frame models with or without staircase will be built and tested in the laboratory to study the influence of staircase on structural lateral load-carrying capacity. Either shaking table or push-over tests will be performed to progressively increase the ground motion or lateral load level to test the structure model to failure. Students taking project 3 and 4 will work together to build the structure model and test the structure in the laboratory. 4. Vibration test and condition monitoring of the frame structure with or without

staircase (Suitable for both undergraduate and postgraduate students) Staircase in a frame structure will affect structural vibration properties. However, in most finite element models of frame structures, the staircase is usually neglected. This simplification may lead to erroneous structural vibration frequency prediction, and hence incorrect structure condition monitoring. In this project, two scaled RC frame structures with or without staircase will be constructed in the laboratory. Vibration tests of the two walls will be carried out progressively at different damage levels to extract the vibration properties. The influence of staircase on frame vibration properties will be examined. Student taking this project will work together with the student doing project 3. 5. Development of equivalent SDOF RC slabs (Suitable for undergraduate and postgraduate students) In blast resistant design, usually a structural component is simplified to an equivalent SDOF system with equivalent mass, stiffness and loads. These equivalent structural parameters are usually derived from static structural properties. Although this approach is commonly adopted in design, it sometimes may not yield very accurate structural response predictions because it is based on static structural properties to model dynamic responses. For example, it commonly agreed that the equivalent mass derived from this approach may not be able to truly reflect the inertia resistance of the structure under high speed loads. The force-displacement relation derived from static tests may not accurately reflect the dynamic force-displacement relation either. In this study, two scaled RC slabs will be constructed in the laboratory. One will be tested to failure by applying static load and another one by dynamic load. Data from static and dynamic tests will be compared, and they will also be compared with those from design approaches. Discussions on the accuracy of using static parameters to derive dynamic equivalent SDOF will be made. Students doing project 5 and 6 should work together. 6. Development of equivalent SDOF RC slabs with FRC strengthening

(Suitable for undergraduate and postgraduate students) FRP strengthening has been a common technique to strengthen and retrofit structures. In this project, two RC slabs with FRP strengthening will be constructed and tested. The results obtained in this project will be compared with those in project 5 without FRP strengthening. The effectiveness of FRP strengthening on RC slab resistance will be


discussed. 7. Theoretical and experimental study of the accuracy of engineering strain in

dynamic tests (Suitable for undergraduate student only) Strain is defined as the ratio of deformation in an infinitesimal length of a material. In practice it is obtained by measuring the deformation in a given length of a structure specimen. Under static loading conditions, this approach gives accurate strain measurement because deformation and stress in the specimen is uniform. Under dynamic loading condition, however, this measurement may not be able to give reliable strain measurement because strain and stress in the specimen are not uniform owing to wave propagation. In theory the true dynamic strain can only be obtained by using a strain gauge of infinitesimal length. In this project, both theoretical and experimental study will be carried out to investigate the errors that might be introduced in dynamic tests to measure the dynamic strains by using various strain gauges. The theoretical study will be based on 1D wave propagation theory. Experimental study will be performed on concrete specimens tested statically and dynamically with different loading rates, and using strain gauges of different sizes. 8. Shaking table tests of small scale frame structures to earthquake ground motions (Suitable to both undergraduate and MSc students) A few scaled models were constructed in 2009 in a FYP project. Owing to the incapability of the existing shaker to break the model, only one model was tested to failure by static push-over test. In this project, the remaining two models will be tested on a larger shake table that will be commissioned next year. The push-over results obtained in 2009 will be used in a numerical model to predict the responses of the scaled model to earthquake ground motions. Numerical simulation results will be compared with the test results. 9. Numerical study of foundation uplift in mitigating earthquake loadings (Suitable to both undergraduate and MSc students) Many passive energy dissipation devices and design techniques are available. Recently some researchers studied the possibility of letting foundation to uplift to mitigate earthquake loading effect. This project will perform numerical simulations to investigate the effectiveness of foundation uplifting on responses of bridge structures. Numerical models of bridge piers fixed, partially anchored, and completely free on foundations will be developed. The bridge responses to earthquake ground motion will be calculated and results compared to examine the effectiveness of uplifting piers on reducing the bridge responses. 10. Numerical simulation of dynamic tensile properties of concrete material using a mesoscale model

(Extended project including summer vacation period)


Concrete material behaves very differently under static and dynamic loads. It is commonly understood that the concrete strength and stiffness increase with the dynamic loading rate, and the ratios of increment under tensile and compressive force are different. Usually a dynamic increase factor (DIF) is defined to model this increase. Many researchers have conducted impact tests to determine the DIF. Intensive reviews of the concrete compressive and tensile DIF obtained by different researchers revealed that the test results varied significantly. A number of studies to explain these discrepancies can be found in the literature. Controversial results have been reported. Most of these studies investigated the compressive DIF. Study of tensile DIF is very limited. This project will perform numerical simulations to study and quantify lateral inertial confinement effect on tensile DIF of concrete materials. Mesoscale model with detailed modelling of concrete mortar matrix, aggregates and interfacial transition zone (ITZ) will be developed to perform numerical simulations.


Supervisor: Professor Yuxia Hu [email protected]

1. Numerical Investigation of Helical Anchor Capacity in Clay Helical anchors have been used for foundations to stabilise transmission towers and pipelines. They are designed to resist pullout loadings. This project is to study the parametric effects on helical anchor pullout capacity. The parameters include soil strength, soil stiffness, anchor spacing and anchor size et al.

2. Numerical Investigation of Caisson Stiffener in Clay Suction caissons have attracted more and more attention from offshore foundation design engineers, since the caissons have potential to provide large pullout capacity for offshore foundations. As the caisson aspect ratio increases, the stiffeners are designed to strengthen the caisson stability. This project is to study the soil failure mechanisms around stiffeners during caisson penetration and pullout.

3. Centrifuge testing on caisson stiffener in clay As above, two-dimensional centrifuge tests will be conducted to study the stiffener effect on caisson capacity.

4. Numerical Investigation of Spudcan Foundation on Three-Layer Soils – stiff/soft/stiff clays Spudcan foundations are used widely to support jack-up structures in offshore oil/gas explorations. When a soft soil layer appears between two stiff clay layers, the foundation capacity can’t be designed based on the top layer. This project is to investigate the soft layer effect on spudcan capacity.

5. Numerical investigation of spudcan foundation on three-layer soils – sand/soft/stiff clays As above, this project is to study the soft clay layer effect on spudcan capacity when the top soil layer is sand.

6. Numerical investigation on mitigation of foundation punch-through failure

on stiff clay over soft clay soils using skirted foundation When a spudcan foundation installed on a soil with stiff clay overlaying soft clay, a punch-through failure may occur. This means that when the spudcan reaches its maximum capacity, it will have a sudden penetration into the lower layer due to the lower capacity of the soft clay layer. Skirted foundation is seen to have the



potential to avoid the punch-through failure. This project is to investigate the potential of skirted foundation to mitigate the punch-through failure on stiff clay over soft clay.

7. Centrifuge testing on mitigation of foundation punch-through failure on stiff clay over soft clay soils using skirted foundation

As above, centrifuge test can be conducted to study the behaviours of spudcan foundation and skirted foundation on stiff clay over soft clay.

8. Soil strength measurements: Penetrometers in layered soils

T-bar and ball penetrometers are proved to be better probes to test soil strength on offshore sites, comparing to the conventional cone penetrometers. However, in layered soils, the measurement of soil strength can be erroneous since the top layer soil can be carried into the lower soil layer. This project is to investigate the effect of top soil layer on the measurement of sub-layer strength.

Pavement Design Projects

(These projects are proposed by pavement industry. Projects PD1~4 are proposed by Russell Clayton from GHD; projects PD5~9 are proposed by Colin

Leek from City of Canning)

PD1: INVESTIGATE THE INFLUENCES OF VARIATIONS IN MATERIAL PROPERTIES ON CRUSHED ROCK BASE Determine the influences on compaction of a base due to variances in grading and level of compaction Carry out static and cyclical triaxial testing on the material prepared to different levels of compaction and grading.

PD2: INVESTIGATE EMULSION STABILIZED CRUSHED ROCK BASE Carry out a literature survey and prepare a test program to determine the basic pavement engineering properties of the material using local crushed granite and local stabilizing materials

PD3: INVESTIGATE FOAMED BITUMEN STABILIZED CRUSHED ROCK BASE Carry out a literature survey and prepare a test program to determine the basic pavement engineering properties of the material using local crushed granite and local stabilizing materials

PD4: INVESTIGATE THE PERMEABILITY OF LOCAL ASPHALT MIXES Carry out a literature survey into the permeability of asphalt with a view to identifying the real permeability of asphalt and seal systems used in WA. Follow up with some laboratory testing that evaluates the permeability of the asphalt and seal systems using realistic operating hydro-static pressures.The laboratory investigation to focus on asphalt extracted from constructed projects and laboratory specimens.

PD5: AN INVESTIGATION INTO THE SUBGRADE CBR VALUE AND TEST METHODS TO DETERMINE CBR VALUES OF SAND SUBGRADES AFTER TRAFFICKING. It has been recognised after many instu investigations that the upper layers of a


sand subgrade consolidate with trafficking, and that testing with a PSP will give blow counts of typically in excess of 20 blows/150mm. This would indicate that for rehabilitation design, either some part of the subgrade may be modelled as an existing pavement layer, or as a very stiff upper subgrade layer.

This may be as a result of consolidation which would imply high insitu density, or it may be some other factor that is not immediately apparent

The investigation should consider:

− Methods of determining insitu CBR o Cone or sand penetrometer o Estimation from deflection testing o Insitu CBR testing o Static cone penetrometer o Clegg impact hammer

and compare these results to:

− Methods of laboratory determination of CBR o Undisturbed CBR on cores o Laboratory remoulded CBR Soaked At insitu MC

The relationships between CBR and modulus as determined by RLT should also be examined, and an attempt at least to remould samples to an equivalent density as that existing and determination of RLT modulus at insitu conditions. The investigation would need to consider the variation of CBR (or modulus) with depth, and consider the pavement modelling procedure, either as a layered subgrade, or a effective CBR based on combining layers eg Japan method.

PD6: AS A FOLLOW ON FROM THE ABOVE, A SECOND STUDY MAY LOOK AT THE EFFECTS OF SAND GRADING, CLAY AND ORGANIC CONTENT, AND THE EFFECTS ON IN SERVICE CBR.

PD7: A FURTHER STUDY INTO THE EFFECTS OF KEVLAR FIBRES IN ASPHALT REINFORCEMENT.

This study was undertaken previously, (Curtin) and trials undertaken in City of Canning. However the results were inconclusive, and a statistically significant number of repeats as to determine the effect on fatigue life and modulus was not undertaken.


It is considered that the results should have demonstrated a positive effect, but whilst apparent performance in a field trial appears to be providing positive effects (3 years), this is not demonstrated in laboratory testing to date.

PD8: MATHEMATICAL MODELLING TO INVESTIGATE THE EFFECTS OF THE NUMBER OF TRAILERS ON MULTI COMBINATION VEHICLES ON THE PERFORMANCE OF PAVEMENT MATERIALS.

This study should consider: − Increased tangential drive forces required to overcome rolling resistance on

level grades − Increased tangential drive forces required to overcome wind resistance − Up grade effects on drive wheels − Acceleration from standing starts The aim would be to determine if multi combinations are overall more damaging

than smaller individual units. This will not be as obvious as it may appear, as steering axles are reduced, and whilst tangential drive forces are increased with trailers, the effects of wind resistance may lead to some interesting conclusions.

PD9:….AN INVESTIGATION TO DETERMINE ENERGY INPUTS OF VARIOUS PAVEMENT

MATERIALS IN WESTERN AUSTRALIA.

Environmental issues are becoming increasingly important in life cycle costing, but many studies are related to overseas or interstate studies where differing proportions of primary energy are used. The study should consider material source, energy input required to manufacture materials, including cement, flyash, bitumen and should include clearing, loss of vegetation and habitat, loss of energy stored and recycled in vegetation, recycling, processing, pavement life etc. The relative transport distance and mode of transport should be considered, as should the onsite energy to place and compact.


Supervisor: Dr Ken Kavanagh [email protected]

1. SIPS Beams SIPS is a North American product consisting of 12mm compressed wood fibre board (sourced from Germany), which comprise the top and bottom flanges of a beam or wall panel. The central section of the beam or panel is comprised of dense polysturene, which is glued under pressure to the wooden faces. The beams or panels are used as structural members in housing construction. The central polystyrene is soft and weak, and the strength is dependent upon deflection. It is proposed to model the beams mechanically to arrive at design strengths in both bending and compression. 2. Wind Interference between Adjacent High Rise Buildings When buildings stand in isolation, they are subject to forces in the direction of the wind (along wind) and perpendicular to the wind (vortex shedding). When a second building is constructed adjacent to the first, the former is subjected to turbulence which is caused by the second. Turbulence can both diminish and increase the wind forces on the isolated structure. It is proposed to study the effect of an upstream building on an instrumented downstream model. These effects will include ‘shielding’, ‘buffeting’ due to turbulence, and increases in vortex shedding. 3. Combined Actions in AS4100 Columns under combined actions in AS4100 are covered in Section 8 of AS4100. The clause for combined compression and bending allows for a change in the effective length (kL) to (L) whenever the member successfully passes a pure compression test (Section 6 of AS4100). This clause is not universally accepted, and it is proposed to test the clause experimentally using building models constructed from thin wire. 4. Wind Effects on Bridges Bridges with concrete decks and either steel beams or box girders are subjected to lateral loads from the wind. These lateral loads often control the design of bridge piers and foundations. The lateral load is a combination of pressure loading and friction drag. It is proposed to study the variation in wind forces as a function of the number of support beams and the beam spacing.



5. Porous Signs and Hoardings The wind code (AS1170.2) gives reduced negative pressures on buildings with porous cladding, but little information on the total load on porous screens. It is proposed to study the loads on both elevated and ground level screens in the wind tunnel. The object will be to derive a formula for drag based on the porosity ratio. 6. Construction Acrow Props Acrow props are adjustable height temporary construction props used in the building industry. They consist of an inner upper pipe and an outer lower pipe, with an overlapped section between. The inner and outer pipes have similar thickness, but have different diameters. There is an air gap when one pipe is placed inside the other. Under compressive load, the gap allows for rotation between the top and bottom sections, which in turn, causes bending in addition to compression. It is proposed to model an acrow prop analytically and experimentally. 7. Elevated Road Signs Road signage is a common feature along freeways and city interchanges. These signs must be readable by passing motorists even in very high winds. Many signs are supported on a single post, and can be either eccentrically mounted or concentrically mounted. It is proposed to study the peak torsional and along wind displacements of such signs as a function of the support stiffness and eccentricity. 8. FRP Steel Beams Fibre reinforced plastics are currently being recommended for the strengthening and repair of existing steel structures. The interaction between fibre and steel is not completely understood, and a project in 2009 highlighted some of the difficulties encountered in the testing and monitoring of such beams. It is proposed to continue the 2009 project using the left over beams with the construction of several new beams. 9. FRP Concrete Beams In 2009, a project studied the use of fibre reinforced plastic to increase the shear strength of concrete beams. Both uni-directional and bi-directional composites were tested. Generally, the uni-directional composites failed in the direction perpendicular to the fibres, and the bi-directional composite was superior. Testing did not include placing fibres on the tension flange. It is proposed to continue this project to investigate the effect of tension flange reinforcement.


10. Anchor Bolts in Tension There are several types of concrete anchors commonly used in the construction industry. The mechanical types include Locksons and Dyna Bolts, and the chemical types are typically Hilti Fasteners. These bolts are frequently subjected to bending, particularly when used as tie down bolts for columns. In bending, some of the bolts go into tension, while the bolts in compression are relatively unaffected. Under wind loading, the bolts in tension are subjected to many cycles of fatigue loading. It is proposed to test various anchor bolts in static tension and tension fatigue to assess their short and long term capabilities. 11). Large Roofs and Stockpiles The Australian Wind Code (AS1170.2) assesses roof pressures using a reference height (h) at the mid-height of the eaves and ridge. The use of the mid-height assumes that the roof has little influence on the wind speed or wind profile (i.e. the roof is small). For grain silos and stockpiles, the building or pile height is large enough to affect the wind profile. This phenomenon is covered by the terrain profile provisions in the wind code, where the wind is accelerated on the upslope. It is proposed to build small and large roof models in the wind tunnel to examine the effect of roof size on the nett roof pressures.


Supervisor: Professor Arcady Dyskin [email protected]

All projects are suitable as Masters Projects

1. Structures based on interlocking blocks (a group of projects) The projects from this group form a part of a large ongoing project focused at developing novel methods in Structural Engineering. This is based on interlocking building blocks/bricks which are the blocks that due to the specifics of their geometry can form self-holding assemblies. Different smooth block shapes have been discovered that allow the interlocking without the aid of keys or connectors. Thus the blocks are produced that can hold together without adhesive, which leads to a range of possible civil engineering applications from demountable structures and pavements (e.g. for air fields) to seismic-proof foundations and can cast a light on the astonishing longevity of ancient dry stone structures.

1.1 FE simulation of heavy duty vehicle tyre loading on OB segmental paver system (with David Yong)

Based on work carried out by Deanna Bramwell in 2009, it was found that the traffic load distribution performance of conventional and interlocking concrete block pavement (ICBP) varies with underlying sub-base stiffness. This would probably explain for why certain ICBP design guidelines, particularly the UK Interpave code, indicated that segmental block paving only serves as a surfacing layer with no structural capability to improve wheel load distribution. In contrast, research carried out in South America, Australia, and Japan indicated otherwise. Deformation observations by port authorities worldwide also indicated that the way segmental block paving is being constructed is crucial to its deformation response. In terms of conventional paving technology, it is widely understood that one of the main load distribution mechanism is through the wedging effect, which effectively locks blocks together to form an interlocked matrix that readily re-distributes wheel loading. However, this mechanism requires certain degree of block rotation to mobilise; the stiffer the underlying material, the less rotation and thus wedging is less likely to occur. This project will involve numerical modelling through ABAQUS/Explicit for the following objectives: • Assess varying sub-base stiffness on conventional ICBP performances; and • Determine if sub-base stiffness affects the load distribution capabilities of vertically interlocking blocks (not limited to osteomorphic blocks). Prior experience on ABAQUS is not a required, but will greatly help.

1.2 FE simulation of eccentrically loaded OB assembly as a column structure (with David Yong) Research carried out by Shuai Li and Guo Peiran in 2009 highlighted the following numerical observations with regards to the utilisation of osteomorphic blocks for construction of load-bearing structures: • Eccentric loading of osteomorphic block assemblies achieve similar response to that of dry-stacked rectangular block assemblies whereby a certain threshold interface



friction is applied; and • Even with adequate threshold interface friction to maximise the eccentric load capacity of osteomorphic block assemblies, the introduction of slenderness effect introduces progressive delamination across the assembly, subsequently leading to much lower bending moment capacity as compared to monolithic assemblies by as much as 30%. The previous research focused on solid osteomorphic blocks. However in real life construction, such blocks are bound to have holes within to facilitate the insertion of reinforcement bars. The question now is: how will such holes affect the eccentric load capacity of OB assemblies, and also with regards to slenderness effects? This will project will follow on from the aforementioned past research procedures using ABAQUS/Explicit.

1.3 Bending stiffness of interlocking structures (Numerical, 3 projects) The ultimate load bearing capacity of interlocking structures as well at their vibration and sound properties are controlled by bending rigidity. As the blocks in the interlocking structures, as well as in fragmented structures are not connected, in the process of bending they can delaminate. The delamination affects the bending rigidity, differently for different types of interlocking blocks. On top of that, the delamination depends upon the magnitude of confining pressure. There are two projects which aim to study the change of bending rigidity and associated mechanical behaviour of fragmented structures due to delamination. The projects are continuation of the last year project on bending of the beam for different types of constraint. Project Buckling of interlocking and fragmented beams involves analysis and computer simulation of buckling and the determination the buckling loads and modes as functions of the beam length. Project Wave propagation in interlocking and fragmented beams involves studying the dynamics and flexure wave propagation in a fragmented beam. Project Bending of interlocking plates involves analysis and computer simulation of bending rigidity and static deformation of fragmented plates. The results will be compared to available experimental data. 1.4 Measuring the vibration damping and sound absorption of interlocking plates A very important property in buildings and foundations is the ability of structural members to dump vibrations and attenuate noise. This property has a number of applications, from noise reduction (both industrial and domestic) to seismic-proof construction. The principle of interlocking offers a new opportunity to design structures with very efficient vibration and noise reduction since preliminary experiments have revealed considerable vibration damping and sound absorption (up to 95% on a specific frequency). The project aims at measuring the propagation of vibrations in the plate and sound propagation through the plate. The project is a continuation of 2007 and 2009 projects. In the course of the project the measurements will have to be conducted in different frequency ranges and under different levels of the constraining force and determine the energy loss. A focus will be of achieving the stability and reproducibility of the results.


1.5 Modelling of in-plane oscillations in interlocking structures In-plane oscillations in interlocking structures are controlled by the specific property of their interface which has different stiffness in tension and compression. This produces new resonances not present in traditional structures. This affects the ability of the structure to dump vibrations and attenuate noise which is a very important property in buildings and foundations. Another feature of interlocking structures is the presence of constraining force. If the compressive force is much larger than the amplitude of the driving force the block separation will not occur and the structure will behave as a traditional linear system. There should be a threshold (or a transition zone) where the structural behaviour is a mixture of both. The project aims at investigating the transition zone, both in terms of the ability to transmit or dissipate the energy of vibrations. This project is based on numerical modelling and is a continuation of a 2009 project.

1.6 Dynamics of bilinear engineering systems (Numerical with A/Prof. Elena Pasternak)

The project deals with engineering structures that contain links or parts with different stiffness in tension and compression. Examples of such systems include: • Structures made of interlocking bricks which interfaces have no stiffness in tension or any mortar-less structures • Mooring lines • Links between train carriages Another group of examples is constituted by • Concrete, rock and rock mass as they usually have different moduli in tension and compression • Granular materials • Materials with thin cracks Characteristic features of such systems are the presence of resonance frequencies which have no correspondence in traditional linear approximation, in particular sub-harmonics, and the ability of the system to be excited by random forces. In many cases the subsequent behaviour becomes chaotic. It is believed that these features can be responsible for catastrophic failures in traditional structures (such as breakage long trains), liquefaction in sands and the extraordinary hight energy absorption and self-healing in potentially unbreakable structures made of interlocking bricks. In concretes and rocks these features could potentially be used for non-destructive control. The project aims to investigate these resonances using one-dimensional system of masses connected by bilinear springs. The numerical analysis will be based on standard procedures of solving systems of differential equations that can be found in any package (e.g. Matlab, Mathcad, Mathematica) with subsequent spectral analysis. Two parallel programs for Matlab and Mathcad have already been produced and tested for the cases of 1 and 2 masses. One of these programs will have to be upgraded to a general case of arbitrary number of masses.


1.7 Mortarless construction throughout history – Classification, analysis and perspective –TAKEN

Mortarless construction is historically first building method. In ancient times before mortar was invented, or readily available, structural stability and integrity was provided by either friction between the structural units (if their weight was sufficient) or by special shape of the units or by machining keys or connectors (usually in wooden structures). These methods required considerable manual labour associated with either lifting of heavy blocks or selection stones of special shape and arranging them in the correct order or machining the connectors. With the advent of mortar, the brick and mortar method superseded the mortarless ones as it ensured faster and more reliable construction. In the last century with the development of advanced manufacturing the interest to mortarless (interlocking) structures resurfaced as it provided the reduction of manual labour on the construction site shifting the weight of manufacturing to factories. Recently the concept of topological interlocking emerged whereby the stability of the structure is provided by special overall shape of the blocks without the need for local connectors. As the building methods seem to make the full circle by returning to the mortarless construction it becomes necessary to look at the history of the technology in an attempt to learn lessons from the centuries of prior experience, in particular in the reasons for the amazing longevity (especially in earthquake-prone regions) of the ancient structures. The project is of historical-conceptual nature. The student is supposed to collect all available descriptions of the mortarless structures, propose a classification based on the current understanding of interlocking and categorise these construction methods in terms of the stability and longevity achieved. Depending on personal inclination the student could dwell into the theoretical foundations of topological interlocking and use this concept to enrich the classification of mortarless construction methods. 2. Ultrasonic testing of models of concrete-like structural materials

(Measurements and Signal Processing with A/Prof. Elena Pasternak) Ultrasonic methods have been used in recent years for non-destructive testing of materials. One of the methods is to use stress waves and measure the velocity of their propagation to determine the material elastic properties, which are affected by both pre-existing defects and accumulated damage. However, the process is complicated by the fact that the wave velocities are also affected by the aggregates. On top of that the acoustic signal gets attenuated due to absorption of the sound energy by the medium and scattering by both damage and the aggregates. In order to overcome these difficulties, firstly the influence of the aggregates should be determined by testing on modelling material with known concentration of particles and, secondly, the waves of different lengths shall be used. This project is a continuation of a 2008 project. It aims at investigation of the dependence of the wave velocities and attenuation upon the wave length (frequency) in heterogeneous materials. The project consists of investigating wave propagation in samples made of steel rods, conducting the spectral analysis and the determination of the velocity of wave propagation and attenuation upon the frequency.


3. Size effect in concrete (Computer Modelling) Numerous experiments demonstrate that strength (tensile, compressive, flexural) of large concrete members can be considerably lower than the strength of laboratory size samples. Testing of large pieces of concrete is expensive, so the laboratory testing is usually the only source of strength data. This implies that the strength reduction with size increase - so-called size effect - must be quantified and taken into account in design of large structural members. One of the reasons for size effect is the presence of defects and cracks in the material. These defects are either introduced during casting or accumulated under the action of load, temperature and environment. Under high loads they can start growing leading to the ultimate failure of the concrete structures. The larger the structure, the more defects it contains, the stronger the influence of the defects/cracks on each other. Modelling this mechanism is the aim of the project. The project will simulate the collective effects of the defects/cracks by considering large populations, computing their interaction and determining the defect/crack which is first to grow. The project will involve setting a Matlab (or any other programming language) model and running simulations. 4. Risk assessment of excavation instability and borehole breakouts in homogeneous rocks Instability of excavations and borehole breakouts caused by failure of rocks leads to the breakage of equipment with considerable financial loss and, in the worst case scenario, loss of life. At large scale instability of excavation can trigger natural disasters like earthquakes. There are therefore serious social and economic needs to improve the stability of excavations and boreholes. In order to achieve this, computer models capable of predicting rock failure for different cases are required. Two issues need to be resolved for such models to be adequate for the needs of mining and petroleum industries are: (1) each element of the model representing the rock should accurately model the realistic rock behaviour. These can be achieved using the information from high quality laboratory tests; (2) the choice of the element size is crucial for the model to be successful. This second issue can be resolved based on the new concept of scalability developed at the School. The aim of the project is to develop the simplest realistic model of rock failure at the openings in rock mass that resolves the above issues. The model will be used to determine the failure extent and provide the means for risk assessment. The project will consist of a number of computer simulations using ABAQUS with realistic rock behaviour specified for the finite element. 5. Modelling of crack growth in compression (computer modelling) Catastrophic collapse of underground excavations and rock masses as well as heavy loaded concrete structures is often caused by sudden crack propagation under the action of high compressive load. Proper understanding of crack growth in compression is therefore of paramount importance for the prediction of failure and the development of the methods of preserving the structures. Extensive experimental studies of this failure mechanism have cast some light on its basics but failed to provide comprehensive understanding because of significant difficulties in conducting precise fracture tests in such heterogeneous materials as rocks and concrete. With the advance of computer technologies, computer simulation and modelling is become a viable and cheap


alternative to experimentation. The research aims at computer simulation of crack growth in compression using a Finite Element model. This project is a continuation of a 2008 project 6. Mechanism of post-peak softening in concrete and rock (computer simulation) Post-peak softening – stress reduction with increasing strain after the peak load (strength) is passed – is a very important characteristic of brittle materials such as concrete, masonry and many types of rock and cemented soil which controls the long term survival of the structures. While being routinely measured in the lab and refereed to, the mechanism of post-peck softening is still far from being understood. Furthermore, there is evidence that the post-peak softening depends upon subtle details of the loading frame, in particular its ability to prevent or otherwise the rotation of the loading platens. The project is aimed at investigating the mechanism of post peak softening and the effect of axial and rotational stiffnesses of the loading frame. The analysis will be based on the fibre model whereby the sample is represented as a set of many parallel elastic fibres with randomly assigned strength, while the loading frame is modelled as two rigid blocks connected by a link with given axial and rotational stiffnesses. The project involves computer simulation of subsequent breakage of the fibres as the blocks are pulled apart with a constant rate. 7. Risk assessment of excavation collapse due to catastrophic pillar failure (with Prof. Phil Dight) The project, being a continuation of 2007 and 2009 final year projects deals with stability of large slot-like opening whose roof is supported by many pillars (parts of rock mass left unmined) – so-called room and pillar mining method. Typically the height of the opening is 5 m, the area - hundreds of metres. When a pillar is broken its load is transferred to the neighbouring pillars increasing the probability of their failure. The strengths of separate pillars can vary a lot, so initially failure of few weakest pillars does not yet pose a problem. However, when a certain number of pillars are broken, the breakage of the next one can trigger an avalanche-type failure of the rest of pillars and, eventually, the collapse of the excavation. The situation is further complicated when the pillars are deliberately removed to utilise the resources left in them. The project will use computer simulation to model the catastrophic pillar collapse. With the aid of this simulation the design for determining the stability of the excavation and the failure risk chart will be refined. An @Risk model will be created to simulate the variability of pillar strength from the known variability of rock strength and pillar width. The information on the distributions of rock strengths and pillar widths will be found in the literature. 8. Methods of stress determination in rocks (2 projects, with Prof. Phil Dight) Rocks at depth are subjected to high in-situ stress produced by the weight of overburden and tectonic movement. This stress is the main cause of rock falls in mining industry and borehole breakouts in petroleum industry. Stress also effects petroleum production and flooding of excavations. Currently there are a number of methods used in stress measurements. The following projects will look into some of from.


8.1 Hollow inclusion cell method The stress determination using this method is based on the interpretation of strain measurements utilising a model of rock deformation. Conventionally, the method assumes that the rock is isotropic, i.e. its response to loading is the same in all directions. However, rocks are rarely isotropic. Moreover, in some cases the elastic module can vary more than 10 times when the loading direction changes. The aim of this project is to conduct computer simulation to analyse the effect of rock anisotropy on the accuracy of stress determination with the Hollow inclusion cell method and, if necessary, modify the method.

8.2 Rock memory methods

The information of the stress distribution in rock man is often limited due to the restricted access to the places of stress measurement and due to high cost of the existing methods of in situ stress determination. Recently, a new approach to stress measurements emerged based on the rock stress memory effect. The man advantage of the method is that it can use the abundance of the rock cores left form the exploration boreholes and potentially having the memory of the stresses they were subjected at the time of extraction. Currently, there exist two methods of stress Measurements based on rock memory: the acoustic emission method (Kaiser effect method) and the Deformation Rate Analysis (DRA). The aim of the project is to calibrate these methods using samples of rock or rock-type materials subjected to known stress and develop recommendations for the stress measurements based on the combined use of these methods. In the course of the project the student will master the techniques of rock testing, acoustic emission measurements and wave velocity determination. 9. Scale effect in determination of rock deformability (Numerical, with Prof. Phil Dight) In situ rock deformability is currently measured by testing rock samples. Rock in the rock mass can be anisotropic with difference in deformability in different directions reaching 2-3 times. In this case one needs to test a lot of samples cut out in a number of different directions. The only economically viable technology currently available is sub-sampling of a core. This method however produces samples of relatively small sizes, which leads to very high variability of the deformability measurements and, subsequently, the necessity to test large numbers of samples. This translates into high cost associated with this stage of the rock mass characterisation. The aim of the project is to investigate a mechanism of variability in deformation measurements in anisotropic foliated rock and quantify it. The project will consist of finite element modelling of layered and foliated rocks and simulating subsampling in different directions. It is anticipated that a new sequential method of subsampling will be designed whereby the location and orientation of the next sub sample is determined on the basis of the results of the testing of previous subsamples.


10. Utilisation of pressure sensitive mixtures in remote stress measurements (Experimental) It has recently been found that liquids and jellies filled with hollow plastic microspheres can considerably alter the velocities of wave propagation even for minute concentrations of spheres. As the wave velocities can be measured remotely, this effect calls for applications in distant stress measurements, especially in Mining and Petroleum Industries. The aim of the project is to study the effect further and investigate a potential for utilising it for stress measurements. The project consists of experimental and conceptual parts. The experimental part involves making mixtures of different concentrations of spheres, putting them in the testing tubes and measuring wave velocities under different pressures. The techniques and the equipment for the tests have been established and verified. As a result of the testing, the concentrations of spheres ensuring the maximum effect on wave velocities should be established. Based on this The conceptual part will review the existing methods of in-situ stress and wave velocity measurements, investigate the ways the mixtures can be injected in the ground and develop recommendations for the use of the proposed techniques for the stress determination. 11. Wedge Failure in Open Pits (Supervisors, Prof. A. Dyskin, Prof. P. Dight) Sliding of wedges in open pits can be assisted or in some cases triggered by external vibrations. The vibrations are regularly produced by production blasting and by seismic events (e.g. earthquakes, rock bursts in adjacent excavations) when they occur. It is hypothesised that the mechanism of this form of slope instability is in temporary friction reduction caused by high amplitude vibrations, mostly when the system wedge-rock mass is in resonance. The aim of this computer modelling project is to check this hypothesis. To this end a simple model of the contact vibration under applied pressure will be developed using Matlab or any suitable computer language. This will be used to gain initial insight before a move complex Finial Element Model of a rock slope with wedges is set up. The stability of the wedges will be checked under applied vibrations of different frequencies. Different types of wedge/slope interfaces will have to be tried. A computer package ABAQUS will be used for the final element modelling. 12. Photogrammetric method of distant strain measurements (Experimental with A/Prof. Elena Pasternak and Dr. Igor Shufrin) Strain and displacement measurement is one of the main methods of stress determination and structural health monitoring. In some cases attaching the strain gauges to the surface is not possible or desirable. The advance of digital photography present a method of displacement (and strain) measurements is based on attaching light luminescent targets and making large numbers of photographs of their movements in the process of deformation. The photographs are then processed using specialised software. The main difficulty with using this method is to eliminate possible errors related to the camera resolution and vibration. This experimental project aims at refining the measuring technique and determining the possible attainable resolution. In particular, the optimal shutter speed, flash duration and distance to the object will be determined. Also, the methods of reducing the camera and


sample vibrations will be research. The measurements will be conducted on loaded samples of different stiffnesses and comparison of the results of the measurements with the ones obtained by conventional strain gauges. 13. Smart ultrasonic dust for monitoring of underground water flow (Two projects. Computer modelling. Jointly with A/Prof. Elena Pasternak and Prof. Rachel Cardell-Oliver) A wide range of geotechnical applications ranging from extraction of geothermal energy to tracing the pollution transport require understanding of water flow which happens at various depths underground. Our ability of monitoring of water flow is currently limited to relatively shallow depths. It is therefore important to develop novel monitoring methods applicable to high depths (up to 10 km in the case of extraction of geothermal energy). A new monitoring system has recently been proposed based on tracing the stress waves induced to the rock by large groups of miniature floating ultrasonic actuators. As the actuators are small the bulk of the energy they emit concentrate in very high frequency (short) waves, which get attenuated by rock heterogeneity to the level undetectable from the ground. We however showed that if the actuators (we call them ‘screamers’) are synchronised to emit pulses (‘scream’) in a tight succession, they interfere in such a way that a considerable portion of their energy pumps into the low frequency spectrum producing waves which can be detected. The development of this idea requires two projects: The first project will develop a simulator to test the algorithms of synchronisation of the screamers and the investigation of the robustness of the algorisms to the adverse environmental factors leading to various delays in the pulse emitting and loss of the screamers. This project would involve considerable amount of programming using Matlab. Objective of the second project is to create a computational model that adequately represents the interference of screamers in the influence of their special locations as well as the locations of the wave detectors. The project will involve modelling of wave propagation in the Earth’s crust and would require the understanding of the corresponding mathematical theories and numerical methods. 14. Modelling crack growth in concrete (Numerical, Matlab, 2 projects) Crack propagation is a major cause of failure of brittle materials such as concrete and rock. Increase of the life time of structures and failure prediction require accurate modelling of crack growth. Concrete and rock are highly heterogeneous materials, which imposes specific conditions of crack growth. A main feature is the development of so-called process zone at the crack tip – a narrow zone where the non-linear processes of deformation and fracture are concentrated. The aim of the projects is to simulate the process zone based on so-called fibre-bundle model whereby material in the process zone is replaced with a layer of parallel elastic fibres with random strengths. When the load exceeds the strength of a fibre it breaks. The load increase continues until sufficient number of fibres breaks enabling a step of crack propagation. There are two ways this model can be implemented. Both ways will be tried and the results compared. The first way is a direct Monte-Carlo simulation of breakage of the fibres situated in the process zone. This is the scope of project Simulation of crack growth in concrete. The


project will be heavily based on statistical simulation and analysis. The second way is to apply homogenisation technique whereby the stress-strain relationship of a uniformly loaded fibre bundle is obtained first and then it is incorporated in the process zone when the crack is modelled. This is the scope of project Homogenised modelling of crack growth in concrete. The project will involve solving the crack equation using the method of collocation. The method will involve the use of complex numbers. 15. Computer simulation of frictional sliding in granular materials (Numerical, Matlab) Granular materials such as sand, some soils and rock debris are often used as construction material. They also form foundations and fault gouge. Plastic deformation of granular material is usually localised over slip lines where sliding is characterised by friction. In order to ensure efficient performance of this type of structural materials as well as to be able to predict failure accurate models are required. Currently, the modelling is based on the assumption that the grains are spherical. The real grains are not. Furthermore, it has been recently discovered that a non-spherical grain produces a specific shape effect that is akin to negative friction. The aim of the project is to study a collective behaviour of the effect of non-spherical shape of grains on frictional sliding. The project involves Monte-Carlo style computer modelling using Matlab or a similar computer language. 16. Modelling of domino effect in instability of shear ruptures and faults (with Prof. Boris Tarasov and A/Prof. Elena Pasternak) Catastrophic propagation of shear fractures and sliding over a fault are major dynamic effects causing excavation collapse. The correct understanding of the physical processes taking place at this phase is extremely important for failure prediction. A recently identified mechanism of this type of instability suggests that during shear crack propagation slender rock blocks are formed and then rotate. The block rotation causes domino effect which is accompanied by high velocity of propagation of the front of rotating blocks and sudden release of large amount of elastic energy. The project aims at investigating this mechanism by considering a simplified models consisting of a set of levers on hinges connected by springs. This system is modelled by a system of differential equations which is to be solved numerically (using Matlab). The numerical results will be compared with results of experiments with a physical model.


Supervisor: Dr Susan Gourvenec [email protected]

The projects offered here concern the bearing response of surface and shallowly embedded foundations and plates. All projects are numerical (rather than experimental) and analyses will be carried out with the finite element software ABAQUS. Previous experience with numerical modelling is not required. The projects are entirely independent of each other. The projects are suitable for undergraduate or masters level students with a grounding in geotechnics. The projects are suitable for visiting students with a geotechnical background who are able to commit to the project for at least 4 months full-time. 1. Effect of embedment ratio on the undrained failure mechanisms of shallowly skirted foundations under vertical loading (Numerical) Historically, offshore platforms have been founded on deep piled foundations, but this is costly and there is increasing interest from the offshore oil and gas industry to optimise design procedures such that shallow foundations are an alternative foundation solution. Skirted foundations are a particular type of shallow foundation that are used offshore and comprise a flat plate with a circumferential skirt that penetrates the seabed confining a soil plug. The skirts aid penetration of the foundation into the seabed and allow tensile resistance to be mobilised due to negative excess pore pressures (suctions) developed within the plug of soil confined by the skirt. This project will investigate the effect of skirt depth on the undrained bearing response of shallowly skirted foundations. Three dimensional finite element analyses will be used to investigate the kinematic mechanisms accompanying undrained failure of shallowly embedded skirted foundations, under general loading. Embedment ratios (foundation embedment to foundation diameter, d/D) between 0 and 1.0 will be considered. The shear strength profile will replicate that achieved in a recent series of drum centrifuge tests. Initial finite element analyses will be verified against the existing experimental data from the drum centrifuge tests. 2. Three-dimensional effects on the bearing capacity of shallow skirted foundations under general loading (Numerical) Much numerical analysis of shallow foundations idealises conditions to plane strain, even when in reality geometry is three-dimensional. This is particularly relevant for offshore shallow foundations which are typically circular, quasi-circular, square or rectangular in plan. Shape effects have a potentially significant effect on foundation response and a better understanding of the three-dimensional kinematic mechanisms governing failure would be a valuable addition to the existing knowledge base. This project will involve three-dimensional finite element analyses to investigate the undrained bearing capacity of shallow skirted circular foundations under general loading. The project will consider varying embedment ratio and soil strength heterogeneity. Results will be expressed in terms of bearing capacity factors and three-dimensional failure envelopes. The results from this study will be compared with those from a previous numerical project in which geometry was idealised to plane strain conditions.



3. Effect of consolidation on capacity of shallow foundations under general loading (Numerical) Existing failure envelopes describe ultimate limit states under either undrained or drained conditions. In reality, the foundation response will vary over the range of response over time (how much time will depend on the coefficient of consolidation of the soil and the length of the drainage path). For foundations loaded in compression, consolidation will have a beneficial effect on capacity. For foundations loaded in tension (e.g. mooring floating facilities), consolidation leads to a reduction in capacity. Therefore an understanding of the effect of drainage is important in determining foundation capacity. This project will use finite element analysis to predict failure envelopes for a shallow foundation under general loading as a function of foundation load and time. 4. Torsional loading of subsea foundations (Numerical) Shallow foundations for subsea installations, such as pipeline end manifolds (PLETs), are subject to considerable torsional loading and relatively low overturning moment. This is in contrast to shallow foundation systems for offshore structures that extend throughout the water column, which are subjected to considerable overturning moments and relatively low torsion. Various studies have considered the combined load capacity of offshore shallow foundations under vertical, horizontal and moment loading (VHM), relevant to foundation systems for offshore facilities that extend throughout the water column. However, relatively little is understood about the effect of torsion on the general load capacity of shallow foundations. This project will develop failure envelopes in VHT load space i.e. for undrained failure under combined vertical, horizontal and torsional load. The project will consider square and rectangular foundations as these are most commonly used for sub-sea installations. The project will compare the results with those from conventional methods of incorporating torsion into bearing capacity calculations to assess the appropriateness of the existing method and the potential efficiencies available by considering torsion explicitly. 4. Capacity of shallow foundations under biaxial moment (Numerical) The loading regime on a foundation is often idealised as occurring ‘in-plane’, i.e. vertical, horizontal and moment loading act in a single plane of symmetry of the foundation. In, reality foundation loading is more complex. For example, a shallow foundation with a permanent moment, due to eccentricity of the superstructure on the foundation, may subjected to a live moment, due to the environmental forces, in an alternative plane. This project will use three-dimensional finite element analysis to identify the effect of bi-axial moment on the undrained capacity of shallow foundations. The results will be used to investigate methods of appropriately representing bi-axial moment in design calculations. Rectangular foundations of varying aspect ratio and embedment ratio will be considered. 5. Effect of embedment ratio on the drained bearing capacity of shallow foundations under general loading (Numerical) The drained response of shallow foundations under general loading is often considered in terms of a work-hardening plasticity approach that has been developed based on the results of small-scale model tests at 1g. The applicability of these results to prototype conditions is questionable due to scale effects. Scale effects can be investigated


experimentally in a geotechnical centrifuge, but this is time-consuming and costly. Finite element analysis provides a convenient and economical tool to investigate the drained bearing response of shallow foundations at prototype scale. For this project, a parametric finite element study will be carried out to investigate the effect of embedment ratio (foundation embedment to foundation diameter, d/D) on the bearing capacity of shallow foundations under general loading. Initial finite element analyses will back-analyse drum centrifuge tests on surface footings and footings with an embedment ratio d/D = 0.5. Once the initial finite element analyses have been verified against the experimental data, additional embedment ratios will be investigated numerically. The parametric study will aim to identify the change of size and shape of the failure surface under general loading as a function of embedment.

6. Behaviour of keying flaps on plate anchors (co-supervised with Dr Gaudin)

Offshore floating platforms are sometimes moored by cables that are attached to plate anchors, embedded within the seabed. Following installation, the plate is ‘keyed in’, i.e. it is loaded via the anchor line leading to rotation to present the full cross-section of the plate to the line of action of the mooring load. Keying leads to loss of embedment and remoulding of the local soil, reducing the capacity of the anchor. It has been hypothesised that the keying behaviour of plate anchors can be improved using ‘keying flaps’ – these are additional portions of plate that are attached to the top of the anchor via a hinge. The concept is that the flap forces the anchor to rotate more rapidly when load is applied, causing keying to be completed whilst the anchor is still at a deeper location. This project will investigate the performance of keying flaps for an idealised plate anchor. Predicted kinematic mechanisms accompanying failure will be used to optimise the arrangement of the keying flap. Results will be presented as failure mechanisms and failure enveloped in general load space for a rigid plate and for a plate with a hinged flap. Results of the numerical analyses will be compared with existing optical measurements from centrifuge tests.


Supervisor: Dr. Ming Zhao [email protected]

1. Numerical study of oscillatory flow induced vibration of a circular cylinder (co-supervisor Prof. Liang Cheng) The offshore cylindrical structures, such as sub-sea pipelines, risers etc., are subjected to wave action. The wave motion is usually modeled by oscillatory flow when the flow structure interaction is studied. The study of wave-induced vibration has been rare compared to the flow-induced vibration. Vortex-induced vibration of a circular cylinder in oscillatory flow will be investigated numerically in this project. The effects of the KC number on the vibration will be identified. 2. Numerical investigation of passive flow control of vortex-induced-vibration (VIV) (co-supervisor Prof. Liang Cheng) If the natural frequency of a sub-sea structure is close to the frequency of vortex shedding, resonance will happen and the structure may be damaged. Vortex-induced vibration is a hazard for sub-sea structures. Measures should be taken to reduce vortex-induced vibrations of structures in engineering practice. In this project passive control of VIV will be investigated numerically. The passive control will be realized by attaching a device such a spoiler or another small control cylinder to the cylinder. The aim of the project will be to study the effectiveness of passive control devices.



Supervisor: Professor Andy Fourie [email protected]

1. Electrokinetic strengthening of soft clays It is now well established that the undrained shear strength of soft clays can be increased through the process of electrokinetic dewatering. The process through which the strength increases is not well understood, as the strength gain is greater than that due to a reduction in water content alone. Some form of particle alteration appears to be taking place. This project will investigate the effect of electrokinetic dewatering on the development of an apparent preconsolidation pressure, an effect that renders the soft clay extremely stiff, even though it has not undergone a preconsolidation process. Based on the conclusions from a study completed in 2009, the laboratory test will be modified to utilise a switching system based on maintaining a constant current, rather than on water level. The project will also require some scanning electron microscopy work to establish the nature of the changes to the particle structure that explain the observed pseudo-preconsolidation pressure. 2. Achieving optimal backfilling of mining voids using blended waste streams In the mineral sands industry, mined-out pits are usually backfilled with tailings, which consists of two distinct materials; an ultrafine clay material, and a fine to medium sand. If not correctly blended and placed, these materials segregate, resulting in poor shear strength and consolidation characteristics of the backfill. If properly blended and placed, a homogeneous backfill results, which can be relatively easily placed into the void. Attention is now focussing on the final settlement of the backfill, so that the desired landform shape can be ensured for the use of final landowners (e.g. farmers). This project will investigate the effect of the relative proportions of the two materials (the ultrafine clay and the sand) on the consolidation behaviour of the blended mix. In particular it will identify the void ratio at which the compression behaviour changes from being dominated by the properties of the clay to one which is dominated by the sand particles – the transition void ratio. 3. The bearing capacity of soft clays beneath a sand layer and the relationship to access time on a mineral sands mine (Suitable for Vacation Work Project) In many mineral sands mining operations in Western Australia, the mined void is filled with a low strength mixture of sand and fine clay material, as soon as possible after mining has been completed. As part of the re-instatement process, the objective is to cover this backfilled material as soon as possible with topsoil and then to begin revegetation procedures. Problems are frequently encountered with earthmoving machinery becoming bogged, or worse still, completely submerged in the soft backfill. This project will develop guidelines on safe access to the backfill surface, with the objective of minimising risk to machinery operators, but improving access time. The project will require modelling of a two-layer system – the soft backfill overlain by a thin layer of sand – with earthmoving equipment working on the sand surface. The modelling



will involve use of a finite element package, plus other analytical techniques such as the method of characteristics. Finally, the project will develop a detailed plan for an experiment in the geotechnical centrifuge which, time permitting, will also be carried out as part of the project. 4. Optimising the use of Biocovers to reduce fugitive methane emissions from temporary slopes The Red Hill Waste Management Facility (RHWMF) is operated by the Eastern Metropolitan Regional Council (EMRC) and provides waste services for its six member councils. The RHWMF takes in excess of 300 000 tonnes of waste per year. Landfills produce large quantities of methane, a significant portion of which is emitted to the atmosphere. Under the proposed Carbon Pollution Reduction Scheme (CPRS) legislation, organisations such as the EMRC will be required to purchase credits for these methane emissions. It is in the interest of the EMRC to reduce its emissions to the atmosphere and hence reduce its CPRS liability. The RHWMF has a large gas capture network in place where methane is converted into a power source. However it has also been identified that fugitive methane emissions may be entering the atmosphere through a number of temporary slopes on site. Research suggests that this methane can be oxidised to carbon dioxide and water by methanotrophic microorganisms. Methane oxidation can be optimised through the implementation of “biocovers” which are designed for maximum oxidation rates. The EMRC is in the process of trialling a number of biocovers on these temporary slopes. The aim of this research project will be to: test the effectiveness of the biocovers in accordance with the UK Environment Agency, Guidance on Monitoring Landfill Surface Gas Emissions; undertake a literature review into the application of biocovers for the purpose of reducing fugitive methane emissions and from this review and initial testing results suggest modifications or initiate new trials that are likely to optimise the performance of the biocovers at Red Hill whilst being sensitive to costs. 5. Converting a portion of a landfill into an aerobic landfill The landfill stages on Lot 11 of the Red Hill Waste Management Facility (RHWMF) were the earliest filled on site. The waste is now between 20 and 30 years old. Landfill gas production has likely peaked. Aerating the landfill is being considered: to stabilise the waste, reduce methane emissions and improve leachate quality. Lot 11 has existing landfill gas extraction infrastructure, which may be able to be used to aerate the landfill with little modification. Ownership of the infrastructure would have to be negotiated as it is currently managed by Landfill Gas and Power on EMRC land. Future contract negotiations may need to make provision for this – perhaps the EMRC would receive use of the infrastructure for aeration in return for a small decrease in gas royalty from other portions of site. The lining system on Lot 11 is believed to be 500mm of varyingly compacted clay. The lining system is known to have failed, as groundwater contamination has been detected in this area. Aerating the landfill may help decrease the impact of any future contamination from this source, by stabilising the waste and improving leachate quality. However,


making a change such as this cannot be done without introducing a number of risks, such as initiating a fire deep within the landfill, causing leachate springs to emerge on the landfill slopes or increased groundwater contamination as a result of larger leachate volumes. A comprehensive study must therefore be carried out, including a detailed literature review and evaluation of aerated landfills done elsewhere. This project will be to evaluate the characteristics of aerated landfill programmes internationally, specifically considering: techniques to retrofit existing gas collection infrastructure; what benchmarks are appropriate for measuring success?; what monitoring is required, and how long must the landfill be kept aerobic before stabilisation is achieved? 6. Stability of residual soil slopes in open pit mines More and more large open pit mines around the world are being developed in areas where chemical weathering has produced deep zones of residual soils. These soils do not have the same engineering characteristics as conventional soils, but are also very different from hard rock, in which most open pit mines are developed. Designers of open pit mines in these residual soils have difficulty in determining appropriate design parameters for the slopes of the pits, as current techniques were developed for hard rock conditions. This project will develop testing techniques to accurately measure properties for use in finite element modelling of open pit mines, and will also require laboratory testwork using shear wave velocity measurements in triaxial specimens and a range of stress-path tests to define the yield surface of specific residual soils. To provide material for the laboratory tests, block samples of intact, undisturbed residual soil material will have to be excavated from one or two sites near Perth, and this will form part of the project. 7. Mine closure: use of closed facilities for construction of wind farm Recent reviews of financial provision for mine closure have shown that most mining companies have not made adequate financial provision; there has generally been a gross underestimation of the true cost of closure. A large component of closure costs is often the requirement for ongoing maintenance, particularly treatment of acid water. Ideally, companies would like to have a (post-closure) income stream to cover these on-going costs. One idea is to turn the tailings storage facility (TSF) and waste rock dumps into assets, through constructing and operating large wind turbines on top of these facilities. The advantages of this concept include: taking advantage of existing infrastructure such as roads, airfields, offices, workshops and electrical cabling, the fact that government approvals should be relatively easy to obtain (given the existing state of the site), and the contribution to regional economies that could accrue by having a power generation facility at the site. This project will evaluate the financial viability of such a scheme, including construction and operational costs, modification of infrastructure to accept inputs to the electricity grid, foundation requirements for the turbines, regulatory and legislative impediments, and social acceptability. It is expected to largely be a desktop study, with some interaction with mining companies required.


8. Developing a mandatory system for reporting Mine Closure financial provisioning and activities The Australasian Joint Ore Reserves Committee (JORC) code was established to set minimum standards for public reporting (in Australia and New Zealand) of exploration results, mineral resources and ore reserves. It ensures that disclosures on the stock exchange are as accurate as possible, providing potential investors with the security of knowing the information is correct. This project will investigate the establishment of a similar code for reporting financial provisions a mining company has made for future Mine Closure, and what activities (if any) have been taken to ensure closure is carried out responsibly. With the increasing penetration of many mining companies from countries with relatively little regulation of mining activities into Australia (and into many developing countries that have no regulatory framework in place), there is the risk of both environmental devastation occurring, plus Australian mining companies being unfairly penalised when working abroad because they adhere to Australian standards whereas others may adhere to no standards whatsoever. If successful, the proposed Mine Closure code will be presented to the Australian Institute of Mining for consideration for future adoption. 9. Developing a facility for testing technologies used for treatment of acid drainage One of the biggest costs faced by many mining companies is the collection and treatment of acid water that is generated by the interaction of oxygen and water with sulphidic minerals in the waste rock and tailings. This project will design and commission a large testing cylinder, into which samples of waste rock from operational mines can be placed and compacted. This waste rock will then be subjected to various treatments, including the addition of lime. Aside from testing the treatment technologies, a number of experiments will be carried out to determine the mechanism of flow that occurs in this material; the experiments will use various tracers, and back analysis of the results will require numerical modelling of unsaturated flow conditions. 10. Risk of liquefaction of cemented paste backfill during curing process Cemented paste backfill is increasingly being used in many Australian mines, as it provides a procedure that improves overall ore recovery rates. The cost of cement is, however, a significant component of the costs of backfill preparation (usually more than 50% of the cost) and there is a financial imperative to reduce these costs. However, safety considerations dictate that the strength of the backfilled stope must be sufficient to ensure the safety of underground workers, both during the filling process itself, and when the backfilled stope is eventually exposed. Liquefaction of the fill soon after placement is a concern in some operations, and crude approaches currently exist for determining the risk of liquefaction. This project will investigate the link between cement content in the fill, the initial density of the fill, and the time after curing, to establish criteria for re-entry times and for exposure risk. Samples will be prepared in curing cylinders and then transferred to the seismic loading apparatus after specified curing times. A primary goal of the project will be to develop guidelines relating cement content and type of tailings to the curing time required to ensure working conditions underground are safe.


11. Wall steepening at KCGM There are plans for both a significant cutback at the KCGM superpit, and some degree of wall steepening, with a view to reducing unit mining costs. There are a number of problematic geological features within the pit, and this project will investigate the potential for future instabilities due to these features if the proposed expansions proceed. Use will need to be made of programs such as Map3D and FLAC, and it will be necessary to work with geotechnical engineers from the site to develop appropriate geological and mining models.


Supervisor: Dr Mehrdad Kimiaei [email protected]

1. Numerical modelling of Jacket launch analysis Fixed offshore platforms are the most reasonable alternative in shallow to moderate water depths. Usually two sets of different in-service and pre-service analyses are needed to confirm the integrity of fixed offshore platforms during their operation life and installation phase respectively. In installation phase of the jackets, when the jacket weight and dimensions become large, or even in case of restrictions in crane lifting capacities, a launching technique can be used. In jacket launching operation, in summary, the cargo barge will be ballasted in a trimmed manner and after applying an initial push-pull force on the jacket, it will start moving on the barge and then finally it will dive into seawater at the end of the cargo barge. This operation is the most critical operation in the entire installation procedure. The failure could result in damage to local members, defects to the barge, overturning of the unit and even total loss of the structure. Main objective of this research is to develop a proper model for launching the jackets (using Orcaflex software) and to study the effects of main operational parameters, including environmental conditions, launch barge specification, ballast, trim angle, friction coefficient, etc on overall response and stability of the jacket and the barge during launch operation. The effects of input parameters will be closely examined by numerical modellings in a series of sensitivity analyses. For postgraduate students, this study can be extended into implementation of this model in the first step of deployment of subsea platforms using pendulous installation method (already conducted in COFS). This project will suit Bachelor and Master students with interests in offshore installation engineering concepts and backgrounds in civil or mechanical engineering. Knowledge of fluid mechanics and hydrodynamic loading is a bonus, but not essential. 2. Structural configuration effects on reliability of fixed offshore platforms More than 6000 fixed steel jacket platforms in continental shelves have been set up all around the world for over the past 50 years. Almost a third of these platforms need to be reassessed for various reasons such as damaged members, installation of new equipment on decks, or the possibility that some of the installations’ or members’ design life are due. To assess the conditions of existing platforms or in design of new platforms, reliability of the structures must be studied. Reserve Strength Ratio (RSR) is a parameter which will be used in determination of reliability of offshore platforms. In structural reliability analysis, Target RSR (showing the relationship between annual probability of failure and the environmental loads) will be compared with Configured RSR (showing the maximum strength which can be achieved



by a platform). Target RSR and Configured RSR are both dependent on structural configuration of the platforms (ie geometry, bracing configuration, member sizes, foundation modelling, etc). Main objective of this research is to investigate the main parameters affecting Target and Configured RSRs of fixed platforms. In a series of numerical analysis, using USFOS software, effects of platform configuration on overall reliability of fixed platforms will be studied. Traditional quasi static and new dynamic methods will be used for pushover analysis in determination of structural reserve strength ratios. Collapse modes of different platforms will also be studied in this research. For postgraduate studies, this study can be extended into comparing the results of different approaches for reliability analysis of fixed platforms, looking at wave on deck effects, and implementation of modal and incremental techniques for dynamic pushover analysis. This project will suit Bachelor and Master students with interests in offshore structural engineering concepts and backgrounds in analysis of structural systems. Knowledge of non-linear behaviour of structural systems is a bonus, but not essential. 3. Fatigue analysis of SCRs considering nonlinear pipe-soil-interaction effects

(Co-supervisor: Prof. Mark Randolph)

As the offshore industry continues to progress developments in deep waters, the preferred riser solutions are still SCRs (Steel Catenary Risers). SCRs can offer the cheapest riser solution depending on specific field, environmental and load constraints. In riser engineering, nonlinear behaviour of SCRs at the vessel hang-off and in the touch down area (TDA) have always been among the major design challenges. The riser-seabed interaction in the TDA is highly nonlinear because of the nonlinear behaviour of the soil and the random nature of the cyclic loading. Current design approaches are based on linear solutions to these nonlinear problems, partly due to lack of appropriate nonlinear models for the interaction involved and partly because linear solutions simplify the fatigue study. These approaches appear to lead to very conservative fatigue design of SCRs for typical values of linear soil stiffness assumed. This research will be in continuation of the studies already started at COFS on fatigue design of SCRs . Main objective of this numerical research is to get a better understanding of fatigue design of SCRs at TDA using a robust nonlinear soil-interaction model recently developed in UWA and implemented in Orcaflex software. In a series of analyses using Orcaflex software, sensitivity of the fatigue life of the risers to linear or nonlinear soil models, static or dynamic analyses, soil parameters and dynamic motions of the vessel will be studied in this dissertation. This project will suit Bachelor students with interests in offshore engineering concepts and backgrounds in analysis of structural systems. Knowledge of fatigue analysis is a bonus, but not essential.


Supervisor: Noel Boylan

[email protected] 1. Influence of water entrainment on pipeline-seabed interaction processes

(Co-supervisor: Dr. David White) Entrainment of water into seabed soil during pipeline-seabed interaction processes (i.e. laying of pipeline, lateral buckling etc) alters the strength properties of the soil and the resulting forces on pipelines. At present, the mechanisms which control this process are poorly understood and are not accounted for directly in design guidelines. This experimental project will examine the influence of water entrainment using novel experimental techniques. Pipeline-seabed process such as lateral sweeping of pipelines and the touchdown of steel catenary risers (SCRs) will be examined to assess the influence of water entrainment.



Supervisor: Asst. Professor Hang Thu Vu

[email protected]

1. A hp adaptive procedure for the scaled boundary finite element method

(Suitability Undergraduate, Master Degree) Abstract: The scaled boundary finite element method involves solution of a quadratic eigenproblem, the computational expense of which increases rapidly as the number of degrees of freedom increases. It is desirable to obtain solutions at a specified level of accuracy while using the minimum number of degrees of freedom necessary. In previous work, h adaptivity and p adaptivity have been considered. This stimulates the investigation to advance the individual adaptive schemes to develop hp- hierarchical adaptivity approach based on a conventional energy norm. This project is suitable for either undergraduate or master student. 2. p adaptive procedure in 3D for the scaled boundary finite element method

(Suitability Undergraduate, Master Degree) Abstract: The scaled boundary finite element method is a novel semi-analytical technique, whose versatility, accuracy and efficiency are not only equal to, but potentially better than the finite element method and the boundary element method for certain problems. In previous works, it was shown that higher rates of convergence can be obtained using p-refinement instead of h-refinement. This stimulated the development of various p-hierarchical adaptive strategies. Numerical studies were performed on various bounded domain and unbounded domain 2D problems. The results indicate these strategies works efficiently. This project extends the past study to examine performance of one proposed p-adaptive technique towards 3D problems. The p- hierarchical adaptivity approach based on a conventional energy norm will be considered. This project is suitable for either undergraduate or master student.

3. Verification of a new technique for design of deep reinforced concrete beams (Suitability Undergraduate - 2 students)

Abstract: A new technique for the design of deep reinforced concrete beams based on linear finite element analysis has been developed. The method has been demonstrated to lead to savings in concrete (compared to the strut-tie approach). However, the designs have not been tested experimentally. In this project reduced scale deep reinforced concrete beams will be designed, constructed and tested in order to verify that the proposed technique leads to safe designs. The project is suitable for undergraduate students. Two students could work together on the project, with one concentrating on two span beams in the later stages and the other looking at penetrated single span beams.



4. Using fundamental solutions with the scaled boundary finite element method to solve 3D problems with side face concentrated loads

(Suitability Undergraduate, Master Degree) A new technique for solving side face concentrated load problems in the scaled boundary finite element method is extended to problems in 3D. In the technique, by employing fundamental solutions for the displacements and the stresses, the solution is computed as summation of a fundamental solution part and a regular part. The singularity of the solution is modelled exactly by the fundamental solution, and only the regular part, which enforces the boundary conditions of the domain onto the fundamental solution, needs to be approximated in the solution space of the basic scaled boundary finite element method. Numerical studies are performed to illustrate the accuracy and highly efficiency of the proposed technique. 5. Develop point-wise error estimator for the scaled boundary finite element

method (Suitability Undergraduate, Master Degree)

This study attempts to formulate a point-wise posteriori error estimator for the scaled boundary finite element method. A framework is developed to show that the error in the quantity of interest equates to an inner product of the error in the solution of the primal problem and the error in the solution of the dual problem. An energy norm error upper bound based on the Cauchy-Schwarz inequality is derived. Numerical studies are performed to establish the accuracy of the proposed procedure and to demonstrate the effectiveness of the scaled boundary finite-element method. This project is suitable for either undergraduate or master student. 6. Develop design tool for steel flat plate structure in compliance with guidance in

API Bull 2V (Suitability Undergraduate, Master Degree -2 students)

Abstract: Steel flat plate structures include thin plates, stiffened panels and deep plate girders. They constitute main components of offshore structures, oil and gas steel platform, ship hull. This project is about development of design tool for steel flat plate structure in compliance with guidance in API Bull 2V. Numerical studies will be performed to confirm the accuracy of design code and to verify the proposed design tool. For design purpose, the material is assumed perfect plasticity. Push-over analysis is performed in Abaqus. Two students could work together on the project. This project is suitable for either undergraduate or master student. 7. Reduction on fatigue life of tubular joints due to inclusion of crossed gussets.

(Suitability Undergraduate, Master Degree) Fatigue life of submerged tubular joints subjected to cyclic wave load is critical to design of oil and gas jacket and appurtenances. It is popular to use crossed gussets to strengthen the joints for static load. However, the induced crossed plates generate extra high local stress concentrations with its sharp corners. These may act as hot spots which


initiate fatigue crack and may lead to joint failure under stress fluctuation. This project studies the effect of crossed gussets on fatigue life of tubular joints. A safe margin based on the gusset dimensions is investigated. When the gusset dimensions are within this safe margin, the effect of the gusset plates should be minimised without the need of employing any improvement of fatigue life by fabrication. The fatigue analysis is in compliance with the guidance in recommended practice DNV-RP-C203. This project is suitable for either undergraduate or master student. Vacation Work for UG 1. Verification of a new technique for design of deep reinforced concrete beams A new technique for the design of deep reinforced concrete beams based on linear finite element analysis has been developed. The method has been demonstrated to lead to savings in concrete (compared to the strut-tie approach). However, the designs have not been tested experimentally. In this project reduced scale deep reinforced concrete beams will be designed, constructed and tested in order to verify that the proposed technique leads to safe designs. The project is suitable for undergraduate students. **Note**: Two students could work together on the project, with one concentrating on two span beams in the later stages and the other looking at penetrated single span beams. If it is going to be shared work, the casual payment rate of $400/wk offered by the school will be subdivided equally among number of participants.


Supervisor: Professor Richard Durham [email protected]

Please note that usually at least 50% of Mining Engineering students get their thesis topics from industry whilst on vacation work over

summer

1. Effectiveness of surface miners Continuous surface miners have been used effectively for many years in road making, tunnelling and mining of “soft” rocks (e.g. coal). Their application in harder rock mining is being investigated by several parties in the iron ore industry. The challenge is to find a theoretical and/or empirical model of predicting how productive they will be in any given rock environment.

2. Carbon footprint estimation (potentially several projects) With the likelihood of a carbon trading scheme in the near to medium future, the focus will be on optimising the carbon footprint of a mining operation. Carbon emissions of various typical mining processes (e.g. trucks, drills, surface miners, in-pit crushers, blasting etc) need to be analysed and modeled, and guidance given for work practices and techniques that reduce them effectively and economically. For an underground mine there is scope to treat the exhaust air before it is released into the general environment. On a more macro level, alternatives to practices such as mine-site power stations (specifically built for the mine and driven by diesel), need to be reviewed and evaluated.

3. Shotcrete markers One of the critical issues with the application of shotcrete is the quality control and in particular ensuring the specified thickness has been applied. This thesis would continue work done in the previous two years into simple markers that let the operator see the thickness of the shotcrete as it is being applied.

4. Haulage simulation The simulation of mining operations is becoming more and more important in understanding potential bottlenecks or inefficiencies. This project involves developing a generalised haulage simulation model using commercial simulation software called Arena. It needs to be able to easily analyse a road network and assign loading and haulage equipment to simulate the network to determine the interactions between the hauls. A similar project may be possible evaluating, for a given fleet, the effect of different maintenance philosophies. For instance is it more cost effective to preemptively service machines or wait until they break down?

5. Modelling caving using discrete particle analysis Modelling the drawdown behaviour of a caving operation as a particulate process, using EDEM software.



Supervisor: Dr. Tongming Zhou [email protected]

1. Dynamic force reduction on a circular cylinder using an upstream rod When a flow passes a bluff body, load (drag) to the structure will be formed due to the pressure difference around it. When Reynolds number exceeds about 49, vortex will be shed from the structure. This will cause extra dynamic forces to the structure. Extensive investigations have been conducted to reduce the forces. In the present project, a commercial CFD software (FLUENT) will be employed to study the drag reduction effect of a small rod installed upstream of a circular cylinder. The objectives of the project include:

• To validate the aerodynamic characteristics for: a single cylinder at Reynolds number of 100 and 1000, a single cylinder with an upstream control rod staggered from the

cylinder at Reynolds number of 100. • To optimize the diameter ratio and location of the control rod for drag reduction.

2. Dynamic forces on an inclined bluff body and its dependence on Reynolds

numbers (2 students) Vortex shedding is a well known phenomenon that occurs when a flow passes a bluff body. The vortices shed from the bluff body can induce vibration, which, at resonance, will result in excessive motion and possible structural failure. There are extensive studies on vortex shedding from single cylinders in a cross-flow (i.e. the incoming flow is perpendicular to the axis of the structure). In many engineering applications, the structures are not necessarily perpendicular to the incoming flow, and yet the flow structures and vortex shedding characteristics of the inclined cylinder wakes are not studied extensively. In the present project, experiments will be conducted in a wind tunnel to study the wake flows of bluff structure (either a circular cylinder or a square cylinder) at different inclination angles between the cylinder axis and the flow. Dependents of the drag coefficients, vortex shedding frequency and Strouhal number on Reynolds number and inclination angles will be studied and compared with that obtained in wakes of cross-flows. The experiments will be conducted in the wind tunnel of School of Civil and Resource Engineering of UWA. 3. Comparison on the effect for suppressing vortex-induced vibration using

helical strakes of different geometries (3 students) Vortex shedding is a phenomenon which occurs when a flow passes a bluff body (e.g. a single or a group of tall chimneys, tall buildings, marine risers for oil production, mooring lines, deepwater structures such as the pipelines). It is well known in the offshore community that the cylindrical bluff structures suffer from vortex induced vibration (VIV) in strong current conditions. The marine risers, for example, also induce the flow around them to separate and initiate vortex shedding. These vortices cause extra dynamic forces and vibration to the risers. VIV should be avoided in engineering applications. This is because: (1) VIV will increase the fluid dynamic loading to the structures, (2) it will also influence the stability of the structures, (3) the vibration of the structures will accelerate



the fatigue failure etc. The above factors will influence both the capital investment of the structures and the expenses for maintenance. Therefore, great effort has been devoted to the control of vortex shedding from a bluff body, both using active methods and passive methods. In the present project, vortex shedding will be suppressed using the helical strakes, which are attached to the surface of the cylinder. The objective of the project is to compare the effectiveness of the helical strakes of different dimensions on VIV suppression. The experiments will be conducted in the wind tunnel of School of Civil and Resource Engineering of UWA. 4. Measurements of forces on two particles of various arrangements in terms of

particle separations and inclination angles (2 students)

(Co-supervisor Professor Liang Cheng) When particles are put in a moving fluid, forces will be formed on them. The force in the streamwise direction is called drag and in the cross-flow direction is called lift. In the present project, you are required to measure the drag and lift forces on the two particles. The two particles can be arranged at various relative locations in terms of their separation and inclination angles. The experiments will be conducted in the wind tunnel of School of Civil and Resource Engineering of UWA. 5. Measurements of forces on the roof of a granary for grain storage (2 students)

(Co-supervisor Professor Liang Cheng) In Australia, there are many granaries for grain storage. In windy season, the cover of the granaries may be damaged due to the strong wind or the large force exerted on it. In this project, you are required to build a model of granary and test in the wind tunnel under certain wind conditions the forces on the cover by measuring the pressure distributions of the roof of the granary model. The experiments will be conducted in the wind tunnel of School of Civil and Resource Engineering of UWA. Vacation Research Project

Title: Flow characteristics and forces of a piggyback pipeline Pipelines in offshore engineering are sometimes arranged in piggyback format with the bigger one for production and the smaller one for accommodating cables and water injection etc. When fluid flows over a bluff body, vortex will be shed if Reynolds number Re exceeds about 49. The Re is defined as ν/Re UD= , where U is the velocity in the free stream, D is the diameter of the cylinder and ν is the kinematic viscosity of the fluid. In this project, the fluid is air with ν = 1.5×10-5 m2/s and density of 1.23 kg/m3. The diameters of the cylinders are D = 8 cm and d = 4 cm, respectively. The gap η/D between the two pipes is varied, namely 0, 0.1, 0.2 0.3, 0.4 and 0.5. The air has a velocity U = 5.5 m/s. There are five arrangements for the pipes with α = 0°, 45°, 90°, 135° and 180°, i.e. there are totally 30 cases of arrangement in this project. You are required to use FLUENT to calculate the forces on the structures for all the cases


and compare them with the experimental results provided.

U incomingflow velocity D

Pipe 1

αd

η/D

α = 45°

α = 90°

α = 135°

α = 180°α = 0°

Pipe 2

U incomingflow velocity D

Pipe 1

αd

η/D

α = 45°

α = 90°

α = 135°

α = 180°α = 0°

Pipe 2


Supervisor: Dr. Daniela Ciancio

[email protected]

1. Non-destructive technique for the characterization of fibrecrete strength in

mining sites using Rayleigh waves (Suitable for Bachelor) (Co-supervisor: Dr. Matthew Helinski1)

Fibre Reinforced Shotcrete has found in recent years many applications, in the mining industry, in tunnel developments and barricades. Shotcrete, as standard concrete, is mainly made of aggregates, sand, water, cement and chemical admixtures, sprayed at high pneumatic pressure. Logistical difficulties in the mining environment can often lead to significant variability in fibre reinforced shotcrete quality. Recently, a new non-destructive technique has been developed at UWA, believed to have the potentiality to provide a very useful method for managing the risk associated with inadequate quality fibrecrete. This technique exploits the relationship between the velocity of propagation of Rayleigh waves (VR) and the unconfined compressive strength (UCS) of the material, to characterize the in-situ performances of fibrecrete. This project aims to investigate:

1) the validity of this technique when varying fibre type an content, chemical admixture content and curing humidity conditions;

2) the very early-age (less than 5 hours) behaviour of shotcrete. 1 Centre for Geotechnical and Material Modeling, University of Newcastle, NSW 2308, Australia, [email protected] 2. Investigation of the Scaled Centrally Loaded Round Panel Test (ASTM C1550)

(Suitable for Bachelor) (Co-supervisor: Prof. Phil Dight2)

The Centrally Loaded Round Panel Test (ASTM C1550) was originally developed for fibre reinforced shotcrete. It is a test that measure the energy absorption up to a certain deflection. The dissipated energy is then used as a parameter to characterize the material and to control its performances. The test is carried out on a round panel of Φ800X75 mm. The main drawback of this test is the transportation of the samples from the site where it is cast to the laboratory where it is tested. Not only during the transportation the sample can be damaged, but also the different temperature and humidity conditions between the source site and the lab might affects the final results. This project aims to investigate the suitability of the same test on a reduce-scaled panel, with the final goal to implement a testing machine that can be used in the mining site. 2 Australian Centre for Geomechanics, UWA, [email protected]





3. Cost effective analysis of the use of Rammed earth in Australian remote areas (Suitable for Bachelor)

In the light of an increasing call for more environmental-friendly materials to be used in residential constructions, rammed earth is considered an engineering material that can offer alternative scenarios to the standard reinforced concrete, brick or timber structures. The potential use of this material in remote areas and the strong Australian contribution in the world in terms of new and innovative designs of rammed earth houses are the motivations behind this project. The research aims to find out if rammed earth can be an alternative cost-effective construction material in remote areas. The suitable candidate for this project is a student studying a double degree in Commerce and Civil Engineering. 4. Rammed earth: study of an alternative engineering material (Suitable for

Bachelor and Master) Currently, despite the increasing numbers of rammed earth constructions in metropolitan areas, the potential use of this material in remote areas and the strong Australian contribution in the world in terms of new and innovative designs of rammed earth houses, an Australian code that regulates the design procedure for this material doesn’t exist. Most of the time, the dimension of structural members are based on “common rules” widely accepted and used by engineers and builders, but never scientifically demonstrated. Moreover, the lack of a scientific approach in these design procedures includes the use of safety factors extremely high that might lead to the over-dimensioning of the structural members and consequentially to a higher economic cost of the structure. Western Australia leads the world in modern rammed earth construction and outside contractors are willing to assist students to move the "state of the art" forward in the field of rammed earth Several topics are proposed:

- investigation of anchorage length of reinforcing steel bars in rammed earth (Co-supervisor: Stephen Dobson3);

- application of rammed earth in floors and footings (Co-supervisor: Stephen Dobson3);

- possible use of rammed earth in interlocking blocks (Co-supervisor: Prof. Arcady Dyskin);

This project will suit someone with interest in structure design and who enjoyed CIVL3112 (structural concrete design) since some main concrete concepts (strut-and-tie modelling, use of reinforcement in brittle materials, etc…) will be applied to rammed earth design. 3 Ramtec Pty Ltd, [email protected]



5. Stress concentration along non-planar bi-material interfaces between aggregate and mortar matrix in concrete (Suitable for Bachelor and Master)

Stress concentration at a sharp V-notch is a topic in fracture mechanics that had been exhaustively investigated in past years. The same cannot be stated for the case of a sharp V-notch between two materials, representing a non-planar bi-material interface. An application of this problem can be found in the meso-scale analysis of concrete fracture, in which concrete is not treated as a homogeneous material, but as a 2 phase-material consisting of aggregates and mortar matrix. Recent results obtained by a finite element have shown that the stress concentration analysis close to the bi-material wedge tip is affected by: i) the angle of the geometry of the aggregate (i.e. the angle of the wedge); ii) the ratio between the Young moduli of the two materials. This project aims to produce some advances in this topic. The ideal candidate is able to use or keen to learn to use final element packages (as Abaqus or other softwares) and other softwares as Matlab and/or Mathematica. 6. Comparison of different Stress Recovery Methods existing in literature (Suitable

for Bachelor) Stress calculations are of interest because in structural analysis and design, stresses are often more important than displacements to the engineer. In the displacement-based FE method, stresses are obtained from the computed displacements, and are thus derived quantities. The accuracy of the derived quantities is generally lower than that of primary quantities. Once the nodal displacements are obtained, the stresses are computed at the integration points of each element and then extrapolate to the element nodes. It is important to highlight that the stresses computed at the same node from adjacent elements will not generally be the same. This drawback requires the use of stress averaging to recover a single stress value at the mesh node. Taking into account that knowledge of statically admissible forces or stresses forms the basis of safe designs of structures, and that the proposed 2007 revisions to AS3600 permit the design of reinforced concrete members using linear finite element analysis, it becomes clear why it is of interest the study of techniques that enhance the accuracy of the stresses obtained by computed displacements. These techniques have the generic name of stress recovery methods (SRM). Recently a new SRM has been proposed (D. Ciancio, I. Carol, M. Cuomo. On inter-element forces in the FEM-displacement formulation, and implications for stress recovery, International Journal for Numerical Methods in Engineering; Volume 66, Issue 3, Pages: 502-528, 2006) that ensures suitably accurate results without imposing high computational costs. In literature different other procedures exist that try to find a reasonable equilibrium between the efforts needed in the calculation of the recovered stresses and the accuracy of the obtained solution. Usually it holds the higher the accuracy the higher the computational cost, and vice versa. This project will examine the benefits in terms of computational cost and accuracy in the results of this new SRM, comparing it with other SRM implemented in commercial FE software.


7. FE simulation of failure modes of masonry prisms (Suitable for Bachelor) (Co-supervisor: Prof. Manicka Dhanasekar4)

This project aims to study: 1) the effect of height of unit to thickness of mortar joint ratio; 2) the effect of changes in thickness of mortar joint; 3) the effect of bond between bricks/ blocks with mortar (cementitious/ glue) layer of masonry structures via FE analysis. The ideal candidate is able to use or keen to learn to use final element packages, as Abaqus or other commercial and non-commercial FE softwares. 4 Faculty of Built Environment & Engineering, Queensland University of Technology (QUT), [email protected] 8. Experimental study of Mode I and Mode II failure of masonry prisms (Suitable

for Bachelor) (Co-supervisor: Prof. Manicka Dhanasekar4)

Although masonry failure is associated with early cracking and crack propagation under compression/ shear/ tension, no systematic evaluation of the energy release rate due to these single or mixed mode cracks has been attempted. Limited information on energy release rate due to interface crack propagation under tension/ shear in unreinforced clay brick masonry is available. There is a need for consideration to cracking in masonry units, mortar and grout in addition to the interfaces. The energy release rate determined allowing for size effects will then be used to formulate characteristic length as a material parameter for inclusion in the constitutive modelling of masonry. Four-point bending tests will be carried out on masonry beams and notched beams, under prescribed displacement and under very slow rate of loading to capture the complete (including post peak) load deformation response. A method to calculate the area under the curve (accuracy important) will be then implemented. 4 Faculty of Built Environment & Engineering, Queensland University of Technology (QUT), [email protected]




Co-Supervisor: Dr. Jeremy Leggoe [email protected]

Proposed Project by CEED Organisation: JP Kenny Pty Ltd

Project title: CFD Investigation of Seabed Shear Stresses Around Subsea

Pipelines Suggested Discipline: Civil Engineering

Project Type: (Final year/Honours, Masters, PhD, etc): Final Year/Honours

If Final Year Engineering Project, is project "Full", "3/4", or "Either"?: Full Site Work Location: JP Kenny, St Georges Terrace, Perth

No of Students 1 at Final year level at feelstu1 of $ 7,200 Total fee: $ 16,000

Brief Project Description: Objective: To use CFD to investigate the variation in seabed shear stresses surrounding subsea pipelines as a parametric function of pipeline spanning/embedment, trench configuration, wave or current attack angle and wave/current properties.

Motivation: On the NWS of Australia, major oil and gas projects typically expend many millions of dollars in stabilising subsea pipelines in order for them to withstand the intense tropical cyclones which frequently affect the area, The integrity of the oil and gas pipelines is of paramount important to both domestic and international energy consumers. While the subsea industry has undertaken considerable numerical and physical experimental effort over at least the past 3 decades to better define the hydrodynamic loads on a pipeline, relatively little research effort has been put into characterising the loads which these conditions apply to the seabed surrounding a subsea pipeline. The aim of this project is to focus on this area.



Supervisor: Professor Barry Lehane [email protected]

1. The influence of particle shape on the mechanical characteristics of granular soils (assisted by Prof. Budhu, Univ. of Arizona) This project represents a fundamental investigation into the effects of particle shape on the mechanical characteristics of granular soils. Initial investigations will involve experimentation using three idealised soils each comprising identical particles with (i) tetrahedral, (ii) spherical and (iii) cubical shapes; these particles will be sourced from the glass bead Industry. The experimentation will include simple classification tests in addition to triaxial and direct shear tests, and will be supported using PFC3D discrete element method analyses performed at the Univ. of Arizona. 2. Piled raft design (in association with Arup) Piled rafts are now recognised as being one of the most cost-effective foundation solutions for a wide range of applications. Piled rafts have not, however, been used extensively primarily because their analysis is usually assumed to require time consuming and complex 3D Finite Element analyses. This project will examine the potential of a new Arup computer program (which is an extension to GSA) by comparing its predictions with case history data and with other software currently used by Industry. The project will also assist in the development of recommendations for parameter selection. 3. Investigation of a new foundation type for wind turbines (assisted by Prof. Powrie, Univ. of Southampton) Monopiles (or single piles) remain the most popular foundation option for wind turbines. This project will explore the benefits of employing a footing in conjunction with the pile to improve the rotational stiffness of the foundation and enable reduced pile diameters to be employed. Experiments will be conducted in the beam centrifuge using sand as the foundation soil; these follow on from a 2009 investigation involving overconsolidated sand. Parallel numerical work assisted by colleagues at the University of Southampton will assist the generalisation of the findings from the centrifuge tests. 4. Steel interface-sand characteristics Experimentation in the siliceous sand at Shenton Park and the calcareous sand at Ledge Point has revealed that chemical processes operating at a steel pile shaft-sand interface can lead to significant gains in pile shaft capacity with time. This project, which is an extension of work undertaken in 2009, will examine the change in interface characteristics using laboratory interface shear tests performed under a variety of conditions. 5. Stiffness efficiency of Pile groups (with Prof. Mark Randolph) Recent research has shown that the interaction between the displacement fields of piles in a pile group is controlled largely by the small strain stiffness (G0) of the soil. This finding will be implemented by Prof. Randolph in a new non-linear version of the PIGLET (excel based) program. The project will initially entail testing of the new version (or versions) of the program. A new series of design charts for pile groups will then be developed, which



will replace the charts used extensively in practice. The student working on this project will also compare PIGLET predictions with existing case history data for pile groups. 6. Soil-structure interaction for offshore pipelines

(with Prof. David White) This project will involve extension of experimental laboratory work undertaken in 2009 to determine the static and cyclic shear strength at the very low effective stresses operating at soil-pipeline interfaces. These results will then be incorporated in a numerical model for soil-pipeline interaction which can be used to assist design for lateral buckling and “walking” of pipelines. 7. Uplift capacity of under-reamed piles A Perth piling contractor installs piles with enlarged bases to enhance both the compressive and uplift capacity. This project will involve a numerical (Plaxis or equivalent) analysis of the uplift performance of piles with a variety of geometries and in varying soil conditions. These predictions will be compared with uplift capacities measured in static load tests. 8. Settlement of piled footings on sand This project will involve experimentation with instrumented piled footings at the UWA sand test bed site at Shenton Park. This experimentation, combined with findings from previous load tests on shallow footings and piles at Shenton Park and with numerical analyses, will be used to formulate a design approach for piled footings on sand. 9. Effects of pre-loading on capacities of shallow foundations The re-use of foundations is a key issue in sustainable urban development. There is, however, little information available regarding the effects of pre-loading on the performance of shallow foundations in clay. This project will extend previous UWA research in this area and involve a series of centrifuge tests on footings in clay as well as parallel FE (Plaxis) analyses. 10. The bearing capacity of soft clays beneath a sand layer and the relationship to access time on a mineral sands mine. (with Prof. Andy Fourie) In many mineral sands mining operations in Western Australia, the mined void is filled with a low strength mixture of sand and fine clay, directly after mining has been completed. As part of the re-instatement process, the objective is to cover this backfilled material as soon as possible with topsoil and then to begin re-vegetation. Problems are frequently encountered with earthmoving machinery becoming bogged, or worse still, completely submerged in the soft backfill. This project will develop guidelines on safe access to the backfill surface, with the objective of minimising risk to machinery operators, but improving access time. The project will require modelling of the two-layer system (soft backfill overlain by a thin layer of sand) with earthmoving equipment working on the sand surface. The modelling will involve use of a finite element package, plus other analytical techniques such as the method of characteristics. Finally, the project will develop a detailed plan for an experiment in the geotechnical centrifuge which, time permitting, will also be carried out as part of the project.


Supervisor: Professor Chari Pattiaratchi mailto:[email protected]

There are a few environmental projects available as shown below: 1 Synthesis of the wave climate between Jurien Bay and Fremantle

(supervisors: Chari Pattiaratchi and Ivan Haigh) As part of the Integrated Marine Observation System (IMOS) several HF radar installations between Lancelin and Fremantle will provide high resolution direction wave data at hourly intervals to a distance 200km of the coast. This is a unique opportunity for a student to examine the variability in the wave adjacent to the WA coast at unprecedented spatial and temporal scales. The radars are already deployed so the data will be available for analysis immediately. 2. Tsunami risk for north west Australia

(supervisors: Chari Pattiaratchi) In this project we will examine the tsunami behavior along the WA coast (Scott Reef, Kimberley, Geraldton, Jurien Bay, Fremantle etc) using a high resolution numerical model already developed. The availability of high resolution data sets along the south-west provide a unique opportunity to examine these effects. Another feature of interest is the role of tsunamis inside ports and harbours. There are many harbours being built in the north-west but even small tsunamis can have a significant effects through the generation of currents, particularly at the port entrances. Another topic could be the effect if tsunamis in regions of oil&gas regions where they may have a influence on offshore installations (such as submarine pipelines, particularly in shallow water). 3. Effects of coastal sea level rise on beaches

(supervisors: Chari Pattiaratchi and Ivan Haigh) Lidar is a technique for obtaining bathymetry and topographic data using a laser technique yielding high spatial resolution data. This type of data has not been available in WA previously. Lidar data from the coastline of southwest Australia, from Two Rocks to Cape Naturaliste is now available. This data provide a unique data set which can be used to identify regions which may be at risk due to climate change (eg coastal erosion, coastal flooding).



4. Modelling of wave dynamics in the vicinity of reef structures

(supervisors: Chari Pattiaratchi and Ivan Haigh)

Offshore reef systems play a significant role in the wave attenuation along the WA coast. This project will apply a wave refraction/diffraction model to investigate the shoreline configurations and bottom habitat distribution to the wave shoaling coefficients. 5. Coastal Flooding in the Swan river/Peel Harvey Estuary

(supervisors: Chari Pattiaratchi and Ivan Haigh)

Increasing sea levels, due to global warming, will increase the number of coastal flood events (note coastal flooding is flooding due to combinations of storm surges and tides rather than river flood events). The student will undertake a numerical model study of the study regions to predict changes to the coastal flood frequency.

the university of western australia · tarpaulin bellowing takes place when it is windy. it is...

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