PhD & Postdoctoral Research Opportunities
We have a number of onging or recent research projects. For more information, please get in touch with the academic(s) concerned. Please note that there is no guarantee of funding being available for any particular project.
Current or recent projects in the following research areas:
PhD Opportunities in Concrete and Construction
Time-Resolved Investigation of Alkali-Silica Reaction
Contact: Dr Tom Dyer
Alkali-silica reaction (ASR) is a reaction which occurs between aggregate particles and cement. It leads to the formation of an expansive gel which leads to cracking of concrete. The reaction is normally monitored by measuring the expansion of concrete. However, this does not provide a clear insight into the mechanism by which gel is formed. A number of models have been proposed to both explain the ASR mechanism and predict expansion resulting from the reaction. However, there have been a number of criticisms of these approaches, particularly because they do not take into account the apparent formation of gel within cracks in the aggregates themselves. This project aims to devise a method which will allow the development of gel in concrete specimens to be monitored using optical microscopy during the reaction process, rather than after the reaction has occurred. It is then intended that an ASR model is devised that takes into account the observed mechanistic features. This model will be validated against existing ASR expansion data.
Obtaining Biomimetic Microstructures in Cement
Contact: Dr Tom Dyer
Many of the mineral products formed by living organisms have microstructures which are highly efficient in providing their required function, such as structural support and protection. In recent years a large amount of research has been carried out to investigate ways in which similar artificial microstructures can be created in various engineering and medical applications. A variety of methods for achieving such "biomimetic" microstructures have been developed. This project aims to utilise bi-continuous microemulsions as a means of directing the formation of cement microstructure as it sets and hardens. Such applications would have benefits for construction materials such as concrete. Mortar and cement pastes made using a range of microemulsion formulations will be characterised in terms of their microstructural characteristics (using scanning electron microscopy and BET nitrogen absorption measurements) surface permeability characteristics and compressive strength. The influence of the microemulsions on cement hydration will also be investigated.
Influence of Phenolic Brownfield Contaminants on the Setting and Hardening of Concrete
Contact: Dr Tom Dyer
Phenolic compounds are contaminants often encountered on brownfield sites. They are capable of retarding the normal reactions of cement, creating problems in situations where fresh concrete is placed in contact with soil. However, predicting the effect of contaminated soil on concrete is complicated by the fact that phenolic contamination is likely to take the form of a number of different compounds which all have different degrees of influence on cement reactions. This lab-based project aims to overcome this problem by studying the extent to which mixtures of these compounds are capable of penetrating through columns of hardening cement. Techniques which will be employed during the project will include x-ray diffraction, Fourier transform infra-red spectroscopy, scanning electron microscopy and isothermal conduction calorimetry. From the results, an empirical model will be devised to assist engineers in devising appropriate measures to prevent harmful damage from phenolic contaminants.
Development of Foamed Concrete
Contact: Dr Rod Jones
Foamed concrete is an increasingly popular material for diverse construction applications, from thermal and acoustic insulation and building elements to mine reinstatement and ground stabilisation. Much of the technical development of the material has taken place in Dundee has led to the successful development structural grade foamed concrete, foamed concrete for use in thermally insulating housing foundations and ground slabs, nuclear decommissioning and the specification for highway applications. It is a blend of pre-formed foam, Portland cement, filler (either sand or waste PFA), high range water reducing and set controlling admixtures and water. Foamed concrete can be produced to have any required compressive strength from 10 to 30 N/mm2 at densities from 800 to 1,400 kg/m3. Around 30 to 60% of its volume is made up of closed cell bubbles arising from the pre-formed foam, which provides the insulation properties of the material. Recently completed projects have also shown that foamed concrete is an ideal material through which, the consumption of primary aggregates can be reduced. This is due to the high volume of air (20%-70%) and that coarse aggregates are not required in the foamed concrete matrix. It has also been shown that foamed concrete can utilise a wide range of fine recycled and secondary aggregates (RSA), which are otherwise difficult to use in any other application, as partial or full replacement for primary sand, and, therefore, are largely going to landfill. This project will be carried in collaboration with ProPump Ltd and will study a variety of following areas, which can be selected on the basis of skill set being offered.
Developing Chloride Resistance Classes for Concrete
Contact: Dr Rod Jones
With much of the test methodologies being resolved for accelerated carbonation, the European Standard Committee for Concrete Durability has requested that a similar exercise is undertaken for accelerated chloride resistance tests. Dundee is leading this work, together with colleagues from Spain and 2 similar test methodologies have been developed. The work will be carried out in collaboration with the Quarry Products Association.
Development of Carbonation Resistance Classes for Concrete
Contact: Dr Rod Jones
For the last four years the Quarry Products Association with the British Cement Association have funded a large project that is aimed at benchmarking the carbonation resistance of UK concretes. One hundred and sixteen concrete mixes have been produced, which represent a unique and comprehensive data set for the UK concrete industry. In Phase 1 of the Project these have been tested for: accelerated carbonation resistance; carbonation in the CEN TS method (this takes 18 to 24 months); electrical resistivity and calcium oxide content. Specimens have been placed on exposure sites in Dundee, Ringwood and in Denmark. For technical and practical reasons the specimens were made in two sets with a gap between the sets so that we could look at initial data and decide whether we were measuring the right things. This led to some modifications to the degree for the second set of specimens. Phase 1 concluded that resistivity is not a good measure of diffusion resistance and, therefore, the attempt to use a combination of an indirect measure of diffusion resistance (resistivity) with a binding factor, based on calcium oxide content, did not provide a robust alternative way of specifying carbonation resistance. In Phase 1, the accelerated carbonation test data were compared with the limiting value approach used in BS 8500 and this analysis shows the benefit of specifying more than one parameter. In this Phase 2 project it is planned to compare the CEN TS carbonation data and the exposure site carbonation data with the limiting value approach used in BS 8500. Complete the testing degree on the specimens already cast and to measure the carbonation depths of the specimens placed on the exposure sites. Use the data to check if the approach used in BS 8500 is both safe and economic and to provide sufficient data to enable informed decisions regarding the updating of EN206 in 2010. Use the data to check and develop the equivalent concrete performance concept with respect to the XC exposure classes.
PhD Opportunities in Fluid Mechanics
Modelling Marine Sediments Using the Discrete Particle Method
Contact: Prof Ping Dong
The Discrete Particle Method (DPM) is a technique to simulate granular flows by tracking the motion of individual particles. Unlike the continuum theory approach where the discrete particles are treated as a solids phase continuum with averaged properties DPM treats particles individually by accounting for all the forces on each particle and the resulting momentum changes when they move and collide. In the sedimentation and liquefaction scenarios, the forces on each particle are mainly due to gravitational force, inter-particle collisions and the drag imposed by the flows around the particles. This project aims to build a 2D model based on the discrete particle method to simulate the sedimentation and liquefaction of marine sediments under wave actions. The research focus will be on the representation of inter-phase coupling and the improvement of numerical efficiency.
Simulation Techniques for Landslides and Debris Flows
Contact: Prof Ping Dong
Flow-like landslides or debris flows can be found both on land and in water. They occur in various recognised types such as falls, slides, spreads, and flows. In the last type, liquefaction can play a major role in generating rapid flow velocity and long run-out distance as the result of the build-up of an excess pore-fluid pressure and the subsequent loss of effective normal stress and shear resistance. This project aims to build a model based on a meshless method to simulate such flow, especially to capture the interaction process between the fast landslide flow layer and the slow deformation of the lower layer.
Numerical Simulation of Turbulent Wave Breaking
Contact: Prof Ping Dong
Wave breaking generates turbulence and complex fluid motion. In shallow water it has considerable effect on sediment suspension and transport. Most existing numerical models can simulate the mean velocity field in the surf zone but are unable to calculate the time-dependent turbulence production, transport and dissipation processes. This project aims to apply a three-dimensional DNS model together with a sediment pickup/advection module to the study of spatial and temporal variation of sediment concentration due to three-dimensional fluid motion under breaking waves on a sloping beach.
Wave-Induced Transport and Transformation of Pollutants in Coastal Sediments
Contacts: Prof Dong-Sheng Jeng & Dr Andrew Brennan
The sediments in many bays and estuaries, and in the nearby seabed in UK are contaminated by pollutants such as nutrients, hydrophobic organic compounds and heavy metals due to discharge of waste from the river, groundwater or/and ocean outfall. The chemicals are accumulated in the sediments largely due to sorption. These materials are however mobile and may return to the receiving water body through mass transfer processes near the sediment-water interface. As the contingent environmental regulations are reducing direct waste discharge to estuarine and coastal waters, the release of pollutants from contaminated sediments is becoming a primary concern for coastal water quality. On the other hand, the mobility of these pollutants may lessen the toxic impact on marine fauna. Water wave driven seepage flow has been considered as an important mechanism for the mass exchange between the sediment and the overlying water body. Most existing models of contaminant release/transfer from the sediment to coastal water incorporate the wave effects through enhanced diffusion, assuming zero net advective transport over the wave cycle. However, it has been demonstrated that the wave interaction with the bed form (sand ripples) can lead to net advective transport. Our recent study indicates that the poro-elastic seabed behaviour under wave loading further enhances the wave-driven seepage flux and the net advective transport. The aim of this study is to advance the much-needed general understanding of the fate of pollutants in contaminated sediments in coastal waters subject to wave actions using single-domain numerical models and laboratory experiments. This project consists of three phases:
- Hydrodynamic model;
- Chemical reaction models;
- Integration of hydrodynamic and chemical models; and
- Physical modelling (centrifugal tests) in the laboratory.
In this project, we are seeking for two PhD students. One will work on Phase 1 & 4, and the other one will work on Phases 2 & 3.
Nonlinear Dynamical Simulation of Water Towers
Contact: Dr Jonathan Kobine
Elevated water towers are common features in many towns and cities. Their purpose is to maintain positive water pressure in the supply system regardless of any changes in the upstream source conditions. However, in regions of seismic or storm activity the proximity of a water tower to population and infrastructure poses an obvious threat. A conventional approach to agitated solid structures is the 'rocking block' model. We seek to extend that approach by modelling a water tower as a solid block with a partially-filled liquid cavity inside. The motions of the block and the liquid are thus coupled in a highly nontrivial and nonlinear manner. The project will offer ample scope to pursue theoretical modelling, computational simulation and/or experimental investigation, with the ultimate aim being to establish the mechanisms and limiting factors associated with catastrophic collapse of the compound rocking system.
Modelling Tuned Liquid-Column Dampers
Contact: Dr Jonathan Kobine
A tuned liquid-column damper (TLCD) is a device that is becoming increasingly popular for the control and dissipation of oscillatory motion in skyscrapers. The standard design involves two identical liquid columns connected together to form a U-tube oscillator. The natural frequency is a function of the liquid fill level, but this is often impractical to alter in situ. An alternative approach is to vary the relative widths of the two liquid columns, in which case the natural frequency depends also on the degree of lateral asymmetry. Research to date has focussed on the fundamental resonant properties of the asymmetric device in isolation from its structural damping role. The project will extend the work into a full consideration of the active damping characteristics by coupling the TLCD to an oscillating structure. The research is open to any combination of analytical, computational and experimental investigations.
Three-dimensional Taylor-Couette flows
Contact: Dr Jonathan Kobine
Taylor-Couette flow between differentially-rotating concentric circular cylinders is a classical problem in fluid mechanics. Its treatment both analytically and computationally is simplified by the azimuthal symmetry of the configuration, which means that only axial and radial velocity components need be considered. In this project the flow is made fully three-dimensional by considering a rotating circular cylinder at the centre of a stationary square cylinder. Finite-element methods will be used to compute the steady flow subject to physically-realistic axial boundary conditions. Of particular interest will be the computation of sequences of nonlinear bifurcations between different cellular flow modes with variation of the aspect ratio and the Reynolds number of the flow domain. It is not known as yet to what extent the equivalent bifurcation schemes from the two-dimensional Taylor-Couette problem remain structurally stable to breaking the azimuthal symmetry of the system.
PhD Opportunities in Geotechnical Engineering
Enhanced Gravity Foundations on Rock for Marine Energy Generators (EGFoRMEG)
Contact: Dr Michael Brown
The objective of the project is to develop a greater understanding of the material controls on the foundation interface behaviour of gravity based foundations on rock. The outcome of the research will be to develop a database of rock/foundation interface properties and improved design procedures that will lead to less conservative design for marine energy generators. It is hoped that through the research modifications to gravity based foundations on rock will also be developed that will enhance their capacity. Greater understanding of the rock/foundation interface behaviour will lead to the development of existing gravity foundation systems that can be deployed in more onerous situations. The use of gravity based systems will allow the movement of generators with low associated costs and will negate the need for costly permanent seabed anchoring systems. By understanding the current limitations of gravity structures to a greater degree it will allow the development of cost effective foundation modifications that will extend the safe working window of the system and allow deployment in more onerous stream conditions without risk to the generator and associated infrastructure. This project currently has funding available for UK and EU students.
Liquefaction Settlements in Stratified Soils
Contact: Dr Andrew Brennan
During earthquakes and other dynamic events, loose sandy soils in a saturated condition can experience a sharp rise in excess pore pressures and consequent strength loss as their structure attempts to compact, a phenomenon known as liquefaction. During and following liquefaction, soil pore fluid redistributes, affecting the settlement of overlying structures. This project will aim to examine the settlement behaviour of structures on liquefiable soils in the particular case when impermeable layers exist in the soil to change this fluid redistribution pattern. The project will involve testing on the university's brand new £500,000 centrifuge-mounted earthquake shaker.
Pipeline Uplift Resistance In Blocky Backfill
Contact: Dr Andrew Brennan
In offshore geotechnics, it is important to ensure that buried pipelines remain buried, and that there is sufficient soil cover to resist any forces that may occur to un-bury the pipeline. Some installation techniques applied to stiffer clays leave this cover in a “blocky” state. That is, the in-situ clay is extracted in large lumps to create the trench, and these then resettle over the pipeline following installation to cover it. Recent research carried out at Dundee has shown that the size of these lumps has an effect on the pullout resistance of the pipeline, as does the presence of sandy soils in the inter-lump voids. This project therefore aims to go perform parametric testing both with the centrifuge and soil element tests to reveal an appropriate model for practical use in such soils.
Numerical Study of the Performance of Pipeline Ploughs
Contact: Dr Michael Brown
Offshore pipelines are generally installed about 1 to 2 m below the seabed surface, which protects them from external loads and the effect of thermal expansion. One of the most common methods of installation is by dragging a plough which excavates a trench in which the pipeline is placed. The material pushed out of the trench is then replaced to form a backfill in a separate operation. The dragging force and velocity of the plough is very important to the offshore industry as the cost of a job is very dependent on the time taken (a boat may be charged out at £200,000 per day). Because of partial drainage conditions, difficult soil condition will require much slower ploughing, more time to be taken on the job and thus more expense. Consequently, an offshore engineer must have an accurate prediction of how their pipeline plough will behave in given soil conditions before fixing their price with the oil company. As a geomechanical (or continuum mechanics) problem, ploughing is very complicated. It involves large soil strains, partial soil drainage and an unusual and complex geometry (the plough) which is pulled through the soil near the surface. As such, there are no rigorous solutions for the expected drag forces at different velocity, but a few empirical relationships have been developed. Furthermore a project is currently underway in Dundee sponsored by an offshore contractor to investigate plough performance through a series of small-scale model tests. The aim of this PhD project would be to add more rigour to the theoretical solutions for the link between soil type, ploughing speed and drag force by conducting series of numerical analysis. It is likely that additional support for the work could be obtained from industry and so real ploughing performance could also be used to calibrate the theoretical model.
An Integrated Approach for Offshore Wind Energy System
Contact: Prof Dong-Sheng Jeng
More Information: Project Home Page
Wind energy has attracted considerable attention from governments, industry and academics worldwide since the oil crisis of the 1970's. It has considerable potential as a source of relatively clean and mostly local energy. With the recent concerns over the use of fossil fuels contributing to global warming, the implementation of renewable energy supplies has been growing strongly; e.g., the annual growth for wind energy has been around 30% (WEO, 2006), albeit from a very low base. In the last decade, on-shore wind energy technology has been intensively studied resulting in a considerable reduction in costs, and is now competitive with fossil and nuclear fuels for electric power generation in many areas worldwide. However, due to the limitations of land-use for onshore wind farms, offshore wind energy (OWE) promises to become an important source of energy in the near future: it is expected that by the end of this decade, wind parks with a total capacity of thousands of megawatts will be installed in European seas. The innovation of this project lies in development of integrated models for OWES. All models available are limited to either fluid-soil or fluid-structure or soil-structure interaction. In this project, we are looking for several PhD students who are keen to work on either one individual components or integration of several models. The whole project consists of the following components:
- Wind model;
- Hydrodynamic model;
- Coastal process model;
- Structural dynamic model;
- Geotechnical models;
- Integration of models; and
- Physical laboratory.
Each sub-project is particularly designed for one PhD project.
Integrated Prediction of 3D Wave-Induced Liquefaction around Breakwater Heads
Contacts: Prof Dong-Sheng Jeng & Prof Ping Dong
More Information: Project Home Page
Breakwaters are vulnerable to the liquefaction of the seabed foundation, a process that can often lead to significant degradation of the foundation in as little as a few years after construction and sometimes even result in total collapse. The inappropriate design or maintenance of breakwaters can lead to catastrophic coastal disaster. For example, the failure of Sines Breakwater in Portugal caused damage equivalent to almost US$1 billion in reconstruction alone, excluding the huge economic and social impacts on the region. A recent example of coastal tragedy due to failure of breakwaters is that of New Orleans during Hurricane Katrina, putting 80% of the city under as much as 6 m of water and causing deaths and personal and economic chaos. The economic loss from the disaster was more than US$15 billion. The phenomenon of wave-seabed-structure interaction (WSSI) has a major bearing on this issue and is central to the design of coastal structures such as breakwaters, pipelines and platforms. Numerous studies of wave-induced seabed response have been conducted since the 1970s, involving the investigations of pore pressure, effective stresses, and displacement. Nearly all of these models have restricted to 1D or 2D cases, which, crucially, represent only part of the problem; little research has attempted to account for real-world, 3D conditions and, as a consequence, the understanding of the dynamics of breakwaters is limited to the individual components of WSSI in isolation, such as the types of wave and the soil characteristics. However, WSSI is a complex, highly-integrated process: to develop new designs and methods of construction and renovation that overcome the problem of seabed liquefaction, analysis and interpretation of WSSI as a whole, unified system in 3D is required. The lack of knowledge of the whole WSSI problem has led to significant uncertainties in breakwater design and management. With respect to seabed stability, most design guidelines compensate for this uncertainty by recommending a conservative approach to design and maintenance for legal and safety reasons; this approach increases costs. The aim of the project is to understand the mechanisms of WSSI in 3D, and to use this as a basis for developing an accurate predictive model for seabed instability around caisson-type breakwaters enabling the better design, construction and maintenance of breakwaters. The project consists of four pahes:
- 3D wave modelling;
- 3D geotechnical modelling;
- Physical laboratory-centrifugal and wave flumes tests; and
- Integration of wave and soil models.
We are looking for three PhD students for Phases 1-3 (one for each).
Seismic Soil-Pile Interaction During Soil Liquefaction
Contact: Dr Jonathan Knappett
Seismic shaking and soil liquefaction have led to the failure of a number of high-profile structures over the past 60 years, including the catastrophic collapses of the Showa Bridge (1964 Niigata earthquake) and the Nishinomiya Bridge (1995 Kobe earthquake). In both of these cases, failure of the piled foundations due to liquefaction effects in the surrounding soil was responsible for collapse. In addition to the potential economic and human costs, the collapse of such vital 'lifelines' can impede the movement of emergency services. The piles themselves are subject to highly complex dynamic loading during earthquake shaking. This includes inertial loading from the superstructure acting at the pile head and kinematic forces from the surrounding ground acting along the length of the pile which lead to horizontal bending within the pile. Additionally, the pile is required to support the dead load of the structure and any additional dynamic axial dynamic loads. These forces have recently been observed to lead to damaging settlement of piled foundations. The aim of this project is to develop interface models which accurately represent the coupled lateral and axial response of a pile in liquefied cohesionless soil (e.g. sand). This may be done by conducting scale model tests of instrumented piles within a geotechnical centrifuge using the Group's earthquake simulator. These model tests will enable the identification of the controlling mechanisms within the soil and inform the development of analytical soil-pile interaction models. The resulting interaction models may then be incorporated as interface elements in numerical simulations for use in seismic design.
PhD Opportunities in Structural Engineering
Object Oriented Programming and Numerical Methods in Engineering
Contact: Dr Ian Mackie
The proposed research focuses on the application of object oriented programming to distributed finite element analysis. The goal is to use the data modeling capabilities of object-oriented programming to develop methods that easily allow PC networks, running standard software, to work in parallel. The projects will focus on the application to numerical intensive finite element problems such as non-linear and dynamic analysis. The work will involve research into numerical analysis and software engineering, particularly object-oriented methods and distributed computing, to develop efficient distributed programs. Therefore, the research will focus mainly on the following aspects:
- The development of distributed computing to finite element analysis on networks of personal computers, both on intranet and internet;
- The study of the most efficient numerical algorithms for distributed computing, including the problems of non-linear statistic analysis, dynamic analysis and eigenvalue problems; and
- The interaction between the numerical algorithms and overall usability of software.
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