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By T Brown

Australia is now committed to the most significant period of infrastructure investment since the 1960s and the current climate of project finance and public private partnership (PPP) model uncertainty means it is imperative that the affordability and certainty in delivery of infrastructure projects is maximised.In light of the current and forecast levels of infrastructure investment it is worth drawing comparison with a similar period of Australian expansion when the nation’s first railways were constructed. Similarly to over a century ago, we are following a trend in rapid development and are already reaping the inefficiencies that could be avoided with broader technical planning and improved client coordination.The original rail networks were developed by the individual states before they combined to form a Federation of states in 1901. As a result of the adoption of different gauges by 1917 a passenger wanting to travel by train from Brisbane to Perth had to change trains six times.Similarly in 2011, there is little parity between Australian states on the quality requirements (performance specifications) for road tunnels. Differences between states start most significantly with the size of the specified traffic envelopes, thus the size of tunnel required. Where ambiguity and differences exist in project documentation, performance specifi cations (PS) and broad technical requirements for road tunnel projects, any associated risk in interpretation ultimately ends up being incorporated in the bidder’s (constructor’s) final sell price.Whilst not nearly as inconvenient as having to change train at each state border, and largely unnoticed by the general tax paying motorist, this paper examines examples of apparent minor differences in Australia’s recently constructed road tunnels to highlight the differences in road tunnel specifications.The paper identifies how these small differences manifest themselves in major price penalties between projects and further, highlights the need for further specification review, refinement and standardisation across road tunnel jurisdictions to increase road tunnel affordability.

Mar 8, 2011

By Kyle T. Chomyn

Multi-disciplinary engineering analysis and advanced modeling techniques were used to identify and develop low cost design modifications to improve a blast furnace hot blast air distribution main that experienced frequent refractory failures. Piping flexibility analysis helped identify the root causes of refractory damage and determine the need for new expansion joints. Finite element analysis was used to optimize a custom-designed elbow-to-elbow tie-rod system, which ensures thermal expansion loads are not placed on connecting piping. Heat transfer coefficients through the elbows were estimated using computational fluid dynamics (CFD) flow modeling. The cast refractory design was changed to a more reliable brick refractory design. Excessive draft was occurring during furnace back-drafting, so the system was assessed using CFD, and a passive flow-reduction spool was designed. This firstprinciples engineering design approach allowed for optimization and verification, ensuring that the new design addressed the root cause of the previous deficiencies.

Aug 17, 2017

By Pedro Pablo Vasquez Coronado, Victor Octavio Tenorio

"Productivity in openpit mines depends on the observation and adjustment of critical phases of operation. As one of the most expensive activities in openpit production, optimization of the load-haul-dump cycle becomes a critical aspect to address. Using simulation techniques and an ad hoc methodology for analyzing the key performance indicators (KPIs) involved in the production cycle, it is possible to compare actual performance and ideal operating conditions and develop an alert system when operating conditions are subpar with the expected production standards.Study objectivesThe purpose of this work is to implement a methodology for optimizing the haulage cycle by identifying and adjusting the factors that affect the cycle time performance. The methodology includes the implementation of an alert system emitting warning messages when one or several trucks are idle, or when the time of completing production tasks is falling outside a predefined value. This alert is compared with predefined KPIs and is used to determine corrective actions.The alert will:• Demonstrate the benefits of time analysis and how this affects the productivity results in the mining process.• Demonstrate the utility of KPIs in the extraction of ore and waste and how they help to identify equipment performance.• Develop software interfaces to visualize the alert system in order to increase awareness in the operations supervisor.• Make recommendations for future applications that can help improve the productive process of an openpit mine.Problem statementTransporting material in openpit mines may require the utilization of high capacity equipment, which also represents an elevated cost per hour. A supervisory system that controls the adequate distribution of trucks and shovels by providing the operational status of each unit shall contribute to increase productivity while subsequently reducing operational costs. Nevertheless, there is an issue with certain dead times such as queue trucks for loading, trucks waiting to be loaded and other delays. This creates inefficiencies in fuel consumption and energy utilization.For the identification of delays, a contextbased system could be required in order to help optimize the haulage cycle time by controlling delays in loading, haulage and dumping. After applying this methodology, efforts were focused in correcting out-of-standard performance values."

Jan 1, 2015

By S. Khallouk, J. Zollinger, J. R. Kennedy, E. Bouzy, B. Rouat, D. Daloz

Titanium aluminides recently replaced Ni-based superalloys as turbine blades in the last LP stage of aircraft engines. To extend their range of use at higher temperature their properties need to be improved, either by alloying or processing. An efficient solution is to reduce the grain size during the solidification process. In the first part of the paper, an overview is given on the possibilities for grain refinement of such alloys, based on literature data and new results. The most efficient grain refinement is obtained with boron addition which leads to boride formations that are detrimental for in-use properties of turbine blades. In this work, the use of the high grain refinement potency of inoculation with non-brittle particles has been used by developing new refractory-based inoculants. The effect of one of these inoculants on grain refinement of an as-cast structure in a Ti-46Al is presented; resulting in a reduction of the grain size by a factor of 3.While less efficient compared to the potency of boron containing alloys, the grain refinement is effective and does not introduce any embrittling particles.

Jan 1, 2015

By D. Milne, G. Snell

"A new method to predict stope hangingwall failure in underground excavations is proposed. This method compares movement rate for stope hangingwalls, determined from changes in strain or deformation, with changing opening geometry. This geometry is represented by the effective radius factor (ERF), a measure of relative distance to supporting abutments from an opening surface point. This strain-ERF (SERF) approach is applied to an instrumentation program for Brunswick mine near Bathurst, New Brunswick. The SERF method for this case study predicted failure at an ERF of 13.9 m and hangingwall failure actually occurred at an approximate ERF of 12.4 m.RÉSUMÉ Cet article propose une nouvelle méthode permettant de prévoir la rupture de l’éponte supérieure des chambres d’abattage dans les excavations souterraines. Cette méthode compare la vitesse de mouvement des épontes supérieures des chambres d’abattage, déterminée à partir des changements aux niveaux des contraintes ou de la déformation, à la géométrie variable de l’ouverture au jour. Cette géométrie est représentée par le facteur du rayon effectif (ERF, de l’anglais Effective Radius Factor), une mesure de la distance relative jusqu’aux appuis latéraux de soutènement à partir d’un point de la surface d’ouverture au jour. Cette approche contraintes-ERF (SERF, de l’anglais strain-ERF) est appliquée à un programme d’instrumentation pour la mine Brunswick située près de Bathurst, dans le Nouveau-Brunswick. Pour cette étude de cas, la méthode SERF prévoyait une rupture à un ERF de 13,9 mètres (m); la rupture de l’éponte supérieure s’est effectivement produite à un ERF d’environ 12,4 m.INTRODUCTIONUnderground stope design can be improved with the installation of field instrumentation. The most commonly used instrumentation for monitoring rock mass behaviour around open stopes is extensometers. The y-axis of Figure 1 represents how the changing rate of movement, measured using either displacement- or stress-type instruments, can be observed over time. The magnitude of movement measured by extensometers can give an approximation of the load on installed support (Milne, Pakalnis, & Lunder, 1996) and a changing rate of movement can indicate approaching instability."

Jan 1, 2018

By S. T. Johansen, B. T. Løvfall, T. Rodriguez Duran

In this paper we develop a physics-based model for lining erosion in steel ladles. The model predicts the temperature evolution in the liquid slag, steel, refractory bricks, and outer steel shell of the ladle. The flow of slag and steel is due to forced convection induced by inert gas injection, vacuum treatment (extreme bubble expansion), natural convection, and waves caused by the gas stirring. The lining erosion takes place by dissolution of refractory elements into the steel or slag. The mass and heat transfer coefficients inside the ladle during gas stirring are modelled based on wall functions which take the distribution of wall shear velocities as a critical input. The wall shear velocities are obtained from computational fluid dynamics (CFD) simulations for a sample of scenarios, spanning out the operational space, and a model is developed using curve fitting. The model is capable of reproducing both thermal and erosion evolution well. Deviations between model predictions and industrial data are discussed. The model is fast and has been tested successfully in a ‘semi-online’ application. The model source code is available to the public at [https://github.com/SINTEF/refractorywear].

Apr 16, 2024

By J. A. Herbst

Fine coal cleaning by froth flotation has become common practice in the U.S. with more than 80,000 tons treated in this way per day. In spite of this large tonnage, developments in the automatic control of coal flotation circuits have lagged significantly behind those for mineral systems. One reason such developments have been limited is that instruments have not been available for the on-line measurement of carbon or ash and another critical variables in coal slurries. A second reason is that the influence of the operating variables on coal flotation has not been completely understood. During the last few years some of the required instrumentation has been developed and an improved knowledge of the flotation process itself has occurred through mathematical modeling; as a result certain control strategies for coal flotation are beginning to emerge. This paper attempts to evaluate several control strategies using a detailed flotation dynamic simulator, DYNAFLOAT. After constructing a process matrix for the system of interest, promising alternatives for linking manipulated and controlled variables have been analyzed. In order to develop combined grade and recovery control strategies, the authors found it necessary to construct a grade/recovery map with the aid of the simulator to drive the system to known final, feasible grade/recovery operating conditions. Finally, an advanced strategy which uses an on-line model to identify disturbances and take control actions is proposed.

Jan 1, 1983

By V 7. 0 / 300 dpi

THE cams at present universally used in stamp mills lift the tappets with an involute form of curve, to which the surface of the tappet is always tangent; moreover, the line of contact between tappet and cam, if produced, would pass through the center of the stem. This is no doubt a desirable feature, but the writer has long believed that it would be much more desirable if the cam were to pick up the stamp without shock, and gradually increase the upward velocity of the stamp throughout its upward movement. The involute form of cam attempts to impart instantly a considerable upward velocity to the stamp, starting it from a state of rest, and the result is a destructive blow, a great deal of noise, and much wear and vibration. The writer has developed a form of cam which will lift the stamp with a motion similar to that of the piston of an engine between the end and middle of its stroke; in other words, harmonic motion, from the point. of zero to maximum velocity. The curve will give this ideal motion only when the stamp is set for the exact drop for which the cam was designed, but the improved cam will not be as bad as the involute cam until the drop is reduced one-half. In other words, if a cam is designed for a 6-in. drop, it will be some improvement over the usual form of cam until the drop is only 3 in. Any cam, whatever its form, must of course lift the stamp in the same number of degrees of revolution; therefore, with this new form, since the stamp starts more slowly on its upward course, it must end up by going faster, the average speed being the same as with the involute cam. The stamp, after it is no longer in contact with the cam, keeps on going up a certain distance, which is easily calculated. It is therefore possible to hang up a stamp without a cam stick, if the fingers are not more than 1/8 in. longer than necessary to hold the tappet above the cam.

Jan 12, 1914

By Junya Tokita

In Japan, packaged explosives have traditionally been used as the most common explosive for tunneling. Recently, some blasting systems such as ANFO with a kettle loader and emulsion explosives with a pump loader have been trialed in order to improve safety and efficiency of the charging process. There are issues with these systems relative to the Japanese market. ANFO dissolves in water easily, and generates ammonia gas when it contacts with concrete. Emulsion explosives need costly pump ing unit s, and there is a need to control residuals in the pump unit. Additionally, there are obstacles by Japanese law to site mixing of emulsion explosives.

Jan 1, 2005

By Robert L. Stephens

"It can be argued that one of the most important property of any material is cost, since this property detennines the applications for which a material can be considered. Despite growing demand and production for commodity metals such as copper, nickel, zinc, lead, and tin, the cost of these metals has been steadily decreasing in real terms. The only way that metal miners and producers can remain financially viable in the long term is by continuing to lower their cost curve through the implementation of new metals production technologies. This paper reviews technological developments in the production of copper, nickel, zinc, lead, and tin that have or threaten to redefine the cost curves for these metals.DisclaimerThe opinions expressed in this paper the author's, and are not necessarily those held by the author's employer, Cominco Ltd.IntroductionThis meeting will discuss many novel technologies and processes for producing metals and materials with specific properties that will enhance the applications ranges for the material or will allow entirely new applications to be developed. However, in every real-world case, the cost of the new material or process is an important property that determines which applications the material or process can be used in. Other properties that are important depend on the applications.A recent press report (1) discussing the potential replacement of aluminum radiators with copper radiators in pickup trucks and sport utility vehicles provides an interesting example to reinforce the importance of cost in materials selection. In this case, the displacement of aluminum by copper is being considered because of the more favorable heat dissipation characteristics of copper. Heat dissipation has become more important due to the development of hotter-burning V-8 and V-6 engines. For this application, engineers also consider cost, weight, size, durability, and manufacturing process. The report stated that the development by the International Copper Association (ICA) of the ""CuproBraze"" manufacturing process for heat transfer products was an important development. This technology produces 845 radiators that weigh less, are more uniform in quality, and are potentially more compact. They are also expected to cost less in high production quantities than copper units produced in the past, last three to four times longer than soldered copper radiators, and the process also eliminates the use of lead solder from the manufacturing process."

Jan 1, 2000

By Abid Adekunte

"Whilst safety is considered to be of high priority in every aspect of engineering projects, it is equally important for designers and contractors to be continually aware of their obligations to the immediate environment and the society as a whole. These include responsibilities to minimise the amount of nonrenewable natural resources and energy used on projects, to reduce carbon foot prints on projects, to minimise the quantity of wastes produced on projects, to minimise the level of pollution on construction sites and to reuse materials and waste products whenever and wherever possible.In other words, professional engineering practice needs to be accompanied by an underlying fundamental objective to improve, restore and sustain the environment. However, achieving this objective requires continuous collaborative interaction and effective communication between the different specialists involved on every project from the early stages. In addition, developing a well-thought-out economical solution is key to achieving the sustainability aspect of the above objective.This paper focuses on the design, construction and management of a recently completed large multi-level basement scheme in Central London, with greater emphasis on collaborative approaches taken by the design engineers, commercial managers, construction managers and site operatives to deliver the most reasonably economical and sustainable solutions to the client. Solutions were based on combinations of general and specialist engineering knowledge, with due considerations for health & safety, sustainability, cost, practicality, time and community requirements.INTRODUCTIONUnderground structures have become vital components of urban life worldwide e.g. tunnels serve many water, wastewater, highway and railway schemes, basements have been incorporated into many urban commercial, institutional and residential developments, while many public underground car parks have been built to deal with the incessant problem of insufficient surface parking spaces in busy urban centres.The safe design, construction and maintenance of underground structures have been well-mastered by the deep foundation industry over the years. However, just like many other areas of engineering, aside the need to satisfy safety requirements, underground construction practice is now faced with a new set of requirements; the demand for more sustainable and cost-effective solutions, with reduced environmental and societal impacts. Designers and managers of underground construction schemes are now compelled to minimise the use of natural resources and energy, to minimise the amount of waste produced, to minimise the level of environmental pollution, noise and disruption to traffic and normal societal life at ground level around underground construction sites. In addition, the recycling of site wastes and reuse of materials have now become important aspects of underground space development. Considerable effort is being put into promoting sustainable development across the industry."

Jan 1, 2017

By Scott G. Britton

Planning is a management tool used to solve problems and provide data and decision alternatives for company growth, profitability, and direction. Strategic planning is defined as the efforts needed to accurately measure the risks of obtaining a result from future actions given a finite number of outcomes. The techniques of strategic planning are being applied more and more to underground mine design as a result of the fierce market conditions underwhich the industry is facing today, and the conditions they will likely face in the future. The objectives of strategic planning are centered on the ability of the operator or company to manuever its limited resources to the best position available under the given future scenarios. This paper briefly examines the most popular techniques for accomplishing these objectives, how these techniques fit into the current mine management decision-making, and what results to expect from these techniques in planning efficient underground mines.

Jan 1, 1985

By M. Buxton

"Advanced data acquisition and process modelling technology provides online data and decision support about different aspects of the resource extraction process. Real-time approaches have recently been applied to utilize the value of this information for improved production control in mineral resource extraction in different operational set ups including coal, polymetallic ore and gold deposits. The key concept of these approaches promotes the change in paradigm from discontinuous intermittent process monitoring to a continuous process and quality management system in the resource extraction process. The framework includes a real-time feedback control loop that rapidly links online material characteristics data acquired during extraction at the mining face, during material handling and processing with a sequentially up-datable resource model. This will allow near real-time optimization of decisions related to long-term planning, short-term sequencing and production control. The contribution reviews recent developments in the three main constituents sensor based material characterisation, rapid updating of grade control models and simulation based optimization for improved production control. Technological readiness is assessed and critical gaps for further technology development are identified. The value added is illustrated by means of selected case studies. INTRODUCTION With the depletion of known and established mineral reserves, the decrease in head grades and the continuing demand of mineral raw materials by the modern society, future exploitation will move towards extraction of deposits under geologically more complex conditions. Complex deposits are characterized by a low continuity in grade, presence of deleterious elements such as arsenic and high irregularity in the geometry of the ore boundaries. The profitable exploitation of such deposits becomes significantly more challenging. To be able to better utilize such unconventional mineral resources of the future, smart autonomous mining systems are needed, which integrate local exploration of spatially varying material characteristics in–situ and have the ability to follow and extract the pay zones in the ore body while minimizing dilution (Buxton and Benndorf, 2013). The main barriers to overcome for the successful economic exploitation are: • effective grade control which will maximize resource potential along the whole value chain, • minimization of handling zero-value material introduced by dilution, thus • reducing unnecessary expenditure of energy and financial resources and • management and control of the geological uncertainty due to limited information available,"

Jan 1, 2017

By C Cavern, G Jacobs, F Durufle, L Ameglio

Airborne geophysics and geomatics is at a crossroads as to whether it remains a viable mapping tool, both technically and commercially, and broadens its potential for new applications (eg environmental monitoring, civil engineering and precision farming). The use of small and stable multisensor aerial platforms to conduct highly flexible surveys flown at a low/reasonable cost of operation is a recurrent wish of many stakeholders in the natural resources exploration and mining industry. Through its Fly Light Airborne Geophysics research program, EXIGE and partners have pushed the development and testing of two new airborne carriers with unique capabilities for geo-surveys: GyroLAG’s gyrocopter and Infotron’s unmanned aerial vehicle (UAV). These carriers are the next generation of versatile and innovative aerial vehicles for remote sensing and monitoring. They are rotary, smart tailored, ultra-high resolution manned (gyrocopter) or autonomous (UAV) airborne platforms that combine the merits of dense data sampling, accurate position location, very low clearance above ground or sea level, slow speed, interchangeable and combined multiple geo-sensors, automatic data quality control and real-time quality assurance. They also have the benefits of being highly efficient, cost-effective, commercially attractive, safe, reliable and easy to deploy and operate. Their technical specifications and multiple advantages compared to traditional aircraft and/or ground crews are presented in this paper. An overview of various geo-sensors (magnetic, gamma-spectrometry, visual, near-infrared and LiDAR) carried on-board is also provided.CITATION:Ameglio, L, Durufle, F, Jacobs, G and Cavern, C, 2015. Light airborne platforms for monitoring mines and minerals, in Proceedings Third International Future Mining Conference, pp 11–20 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By R L. Langak, R A. Heins

The use of differences in specific gravity between minerals to separate them has long been utilized in the extractive industries. The environmental and cost benefits of the commercialized forms of these processes are well understood and widely used. Gravity concentration is used inter alia in the primary beneficiation of gold, diamonds, coal, tin, ferrous metal ores and andalusite. The potential for economic loss due to poor performance of these gravity processes is significant, but diverse in manifestation and regular process monitoring can prevent or at least reduce these losses. The measurement of performance of gravity processes has always presented a challenge, due primarily to the masses of material involved and the physical nature of the processes, generally typified by long reporting time, and hazardous materials (such as Tetrabromoethane) for float and sink type tests. The development of density tracers has improved this situation, however recovery of these tracers from the process streams created the next set of challenges, requiring significant manpower to physically remove tracers from product dewatering screens. Additions to these tracers (magnetic or x-ray fluorescent) eased the recovery mechanism issues but made them much more expensive to produce, hence operators became concerned about losses during process testing. In addition, magnetic recovery of smaller size tracers by a magnet suspended above a loaded screen panel is still problematic. The development of new low cost magnetic tracers has improved statistical significance of tracer tests, as the tracers themselves can be bought and used in much larger quantities, whilst still remaining economically viable. Coupled with the development of effective magnetic recovery technology, such as the Gekko MagScreen, for even fine sized tracers, on-line, continuous tracer testing is now becoming a reality. Whilst the development of high technology radio frequency detection tracer systems continues, enabling the real time measurement of the process and interpretation of results, miniaturization and recovery of these tracers, which is critical given their costs at present, remains an issue. Keywords: Gravity, process measurement, tracers, magnetic recovery

Jan 1, 2006

By J. Bednar, R. R. Rogers, W. Dingley

"Zinc is by far the most important metal used for protecting steel from the ravages of corrosion, and cadmium is also used extensively for this purpose. These metals are applied by electrodeposition in cyanide baths when a particularly good appearance and high throwing power are required. One great disadvantage in using these baths has been the decrease in cyanide concentration and the increase in carbonate concentration that takes place during the plating. Another disadvantage has been the development of serious embrittlement in high-strength steels. The present authors have developed new cyanide baths for electroplating both zinc and cadmium on steel. These baths are stable in composition during plating, they have not produced appreciable embrittlement in the high-strength steels that have been investigated up to the present time, and they permit the use of considerably higher plating current densities. In addition, they produce extremely fine grained coatings that are attractive and have excellent adherence and covering properties. Brighteners can be used in the plating baths if bright finishes are required."

Jan 1, 1967

By D. Groenveld, M. Rozou

"Recent trends move towards automation, smart sensors, internet of things, powerful DCS, and more data. Are those trends already utilized in a real time production environment? Today operators still have to monitor several complex processes at the same time and predict their behavior based on an overwhelming amount of data available.The fact of the operator being overloaded and humans being unable to process multivariable problems shows the need of a tool merging essential data and providing consistent, sound decisions for long-term profitability.This paper shows a successful execution of ABB’s process improvement services in Aitik (Boliden SA), a copper mine located in Sweden. Soft sensors, fuzzy rule blocks and model predictive control were seamlessly integrated in the control system of the grinding area, resulting in proper control of mill loads and particle size without violation of any constraints.INTRODUCTIONDepending on the ore characteristics and the targeted plant capacity, the design of the grinding circuit may vary significantly. Typically, the circuit consists of several mills (rod, ball, SAG, AG) in series and/or parallel with a number of classifiers and sumps at appropriate locations. The goal of the grinding section is to reduce the ore particle size to a level that enables efficient separation between gangue and precious metals in the subsiding processing step. The trade-off between quality and quantity has to be made. It is also crucial to execute this process step at the lowest possible energy and grinding media consumption.An optimal grinding process controller must manage to maintain a given fresh feed level while keeping the product size within a given range without violating any constraints such as power, torque or load limits. To accomplish the aforementioned, it is necessary to manipulate the ore feed rate, water feed rate and the mill speed. The most significant disturbances adding another degree of complexity to this control problem are ore hardness and the amount of circulating load."

Jan 1, 2016

By John R. Lotz

DEVELOPMENTS in Iran currently arousing interest in a considerable portion of the world, particularly on the part. of that country's immediate neighbor on the North and in our own country, an inseparably related to and largely dependent upon the government's attempts to strengthen its economy and improve the standard of living of its people. These efforts are encompassed by provisions of the Seven-Year Development Plan recently enacted and not, in the process of implementation. It is a fine example of what one financially sound but extremely backward and poorly equipped country has undertaken to do on its own account and with its own resources. This Seven-Year Plnil was formally authoriztld by an act of the Iranian Parliament in February 1948. Its stated objects are to carry out such plans for the development of the country and its economy as ail1 raise the standard of livinc: and standard of education of the people, and re- duce the cost of living. A seven-yrar program for carrying out the work within the limits of appropriations was assigned under the law. The total amount to be expended during the seven- year period was fixed at the equivalent of $670 millioil at current rates of exchange.

Jan 1, 1950

By M Stewart, J Petrie, L Basson

This paper explores tools which have the potential to promote and assess the formation of partnerships between the minerals and energy industries to enhance the economic, environmentally responsible and socially acceptable use of energy. There is a need to look at energy provision and energy services in an integrated manner with key drivers for economic development û both locally and regionally. The minerals sector will remain highly significant to regional economic development in a number of globally significant regions in the medium term. Furthermore, mining, minerals and metalsÆ projects are both consumers and, in some cases (potential), generators of large amounts of energy (electricity included). It is therefore appropriate to focus on the promotion of partnerships between energy providers and the minerals sector which seek to improve resource efficiency within the combined minerals/energy envelope, guided by the tenets of Sustainability.Whilst there has been considerable development of systems analysis tools in recent years to address this sort of æcomplex systemsÆ analysis (Life Cycle Management, Cleaner Production and Industrial Ecology arguments for example), there is no effective roadmap available to decision makers to guide the selection and exploitation of these tools in different contexts. Our previous work developed a Decision Support Framework (DSF) which provides some guidance here, but only within the context of coal-based power generation. The DSF employs the tools of Multi Criteria Decision Analysis (MCDA), within which trade-offs between competing objectives are explored in such a way that alternatives can be compared without necessarily reducing all the different cost and benefits to a common basis (eg a monetary basis). Even if the existing DSF is extended to include all aspects of supply-side management, it is still lacking the necessary tools to analyse energy providers as dynamic network partners within minerals projects (or indeed any resource or manufacturing sector). New models are required for this, which firstly, seek to characterise such network structures, and secondly, enable the application of the necessary analytic tools to exploit these partnerships and networks for optimal performance.This paper explores the development of such an integrated set of network analysis tools, and their relation to the DSF. Due consideration is given to the choice of the attributes needed to characterise partnership linkages and network integrity (eg security of supply of electricity), and the efficiency of material transformations within any node of the network (as a function of energy consumption), and the impact that this has on the viability of other linkages (eg due to reduced availability of raw materials). We discuss how these perspectives help shape the form of objectives to be considered by MCDA.

Jan 1, 2004

By Vojtech Gall

Pre-support measures for urban tunneling have seen a substantial development in the recent past. Ground improvement techniques, pipe-arch and spiling methods now allow for non-disruptive tunneling at very shallow depths under sensitive structures, rail tracks and roadways. The paper presents experience gained on national and international projects built over the past decade that represent case histories and therefore may be used as guidance for the development of similar solutions for future tunneling projects at shallow depths. Reference projects include tunnels for the Washington, DC Metro, London Underground, Dulles Inter-national Airport, Busway tunnels in Boston and the Ft. Canning Tunnel in Singapore.

Jan 1, 2008