Flow Behaviour of Pond Ash Slurry and Shrinkage of Pond Ash Stowed Mine Area

Backfilling enables complete or around ninety percent extraction of coal from the seam and then filling the mine voids with mill tailings; sand or excavated stones etc. which provides additional ground support by constraining lateral deformation of surrounding coal pillars and roof. However the overall feasibility of the backfill operation with different materials has to be studied in detail. The objective of this project is to evaluate the suitability of using pond-ash as backfill material over fly ash and sand in respect to shrinkage of the stowed area. The shrinkage study is done with the help of numerical modeling in FLAC of a mine KTK-5 where pond-ash stowing is going to be implemented. The physical properties like bulk modulus, shear modulus, cohesion, friction angle etc. were also found out through experiments which are required during the numerical modeling. Moreover an effort has also been made to develop comprehensive flow model using CFD and then use the model for predicting pressure drop, volume fraction etc. A 20m pipe with diameter of 20cm is modeled, through which flow is conducted where modeling and meshing is done using ANSYS Fluent. High viscosity fly and pond ash slurry with different concentrations up to 70% by weight of pond ash is passed and for each concentration different velocities are used and pressure drops is calculated. MDD ranges from 1.07gm/cc to 1.27gm/cc. With increase in compaction energy MDD increases due to the closer packing of pond ash particles and OMC decreases from 38% to 28% approx. which might be due to the increase in moisture content leading to less friction between the particles and promoting compact packing with increase in compaction which in turn decreases voids and increase saturation limit. The settling rate for the sample is found to be around 30% with water-liquid (phase1) and pond-ash (phase2). Velocity of 3.5m/s of the paste are optimum with respect to pressure drop. The FLAC simulation yields factor of safety (FOS) after excavation of one pillar with no fill to be 1.5 whereas with pond ash fill it is 2.7. Similarly FOS after stowing with pond ash in the voids of two pillars was found to be 2.5 whereas without fill it was 1.2. After excavation of two and half pillars FOS was calculated to be 1.9 with pond ash fill and 1.0 without fill

The Mechanical Behavior of Salt X

Rock salt formations have long been recognized as a valuable resource - not only for salt mining but for construction of oil and gas storage caverns and for isolation of radioactive and other hazardous wastes. Current interest is fast expanding towards construction and re-use of solution-mined caverns for storage of renewable energy in the form of hydrogen, compressed air and other gases. Evaluating the long term performance and safety of such systems demands an understanding of the coupled mechanical behavior and transport properties of salt. This volume presents a collection of 60 research papers defining the state-of-the-art in the field. Topics range from fundamental work on deformation mechanisms and damage of rock salt to compaction of engineered salt backfill. The latest constitutive models are applied in computational studies addressing the evolution and integrity of storage caverns, repositories, salt mines and entire salt formations, while field studies document ground truth at multiple scales. The volume is structured into seven themes: Microphysical processes and creep models Laboratory testing Geological isolation systems and geotechnical barriers Analytical and numerical modelling Monitoring and site-specific studies Cavern and borehole abandonment and integrity Energy storage in salt caverns The Mechanical Behavior of Salt X will appeal to graduate students, academics, engineers and professionals working in the fields of salt mechanics, salt mining and geological storage of energy and wastes, but also to researchers in rock physics in general

Impacts of Western Coal, Oil Shale, and Tar Sands Development on Aquatic Environmental Quality: A Technical Information Matrix; Volume 1 Introduction and Instructions

Introduction: The Upper Colorado River Basin contains vast deposits of coal, oil shale, and tar sands, which could undergo extensive development should oil prices rise or an international situation restrict oil imports. Naturally, the prospect of development of these alternative fossil fuels resources has led to concern over how extraction and conversion activities will impact environmental quality. A thorough understanding of the nature and magnitude of the resulting envionemental impacts is a necessary prerequisite, if the costs and risks of such activites are to be weighed against the economic benefits. When we set out to evaluated these costs and risks, it soon became obvious that the voluminous literature in this area is difficult to access, often repetitive, and not well integrated into state-of-the-art reviews. This led us to realize the need to categorize and collate the results of such energy-related impact research in a way that would go beyond the compilation of a bibliography, or even keyworking relevant citations. The form of presentation that we eventually selected was the technical information matrix presented in this report. This matrix consists of information on the impacts of coal mining and conversion, oil shale mining and retoring, and tar sands development on four aspects of aquatic environmental quality: surface water and groundwater chemsitry, aquatic ecology, and aquifer modification. The report consists of three parts. This introductory volume contains instruction for use of the technical information matrix, a glossary, and sources of data on energy development and environmental impacts. Two additional looseleaf volumes contain the coal (II), and oil sahel and tar sands matrices (III), respectively, along with the corresponding matrix references and a bibliography of general (summary or overview) references. Each matrix volume also includes a list of symbols and abbreviations used in the matrix. Qualitatively, information on the three categories of fossil fuel development differs principally in amount, type, and geographical specificity. Coal extraction is a well-studied process in the East, where acid mine drainage and metal toxicity are well documented. In the West, surface mining of vast arid and semiarid tracts, as well as generally more alkaline mine drainage, has been less thoroughly studied. Nonetheless, commercial scale operations have been in place for a sufficiently long period, even in the West, to ahve produced a reasonably large data base. Coal conversion processes, although new, have also reached the commercial scale, and information is becoming relatively abundant. Conversely, environmental information is not generally availabel for the Scottish and Russian oil shale industries, or for the primitive industry in the Colorado Basin earlier in the century, and the present day oil shale industry in the west is insufficiently developed to have produced commerical scale case studies. Most information at present comes from pilot or semi-works facilities, and the impacts of a full-scale development over a 20-30 year project life are difficult to predict. Although Alberta, Canada, has a well developed tar sands industry, site specific information on tar sands development in the Colorado Basin is lacking. There are several areas of ommission in the coverage of sources of fossil fuel impact on aquatic environmental quality. Petroleum drilling, whose principal impacts in the Colorado Basin are related to interconnection of saline with good quality aquifers, creation of saline surface springs during exploration and illegal brine disposal practices has been omitted. Also, we have not pursued the effects of acid (e.g., Sox) base (e.g., NH3) or volatile metal (e.g., Hg) emissions to the atmosphere and their subsequent effects on downwind ecosystems when they are returned by precipitation or dry deposition. We have generally omitted the toxicological literature relating to occupational exposure (e.g., skin painting tests, etc.), as well as the impacts of water withdrawals on fish habitat through reduction of natural instream flows. In the latter cases such impacts require site specific consideration of hydrology and channel morphology. The more than 1300 citations in these matrices were gathered from a wide variety of refereed journals, symposium proceedings, government documents, abstracting services, and personal communications with researchers. The papers cited emphasize the period 1970-1981. Greatest emphasis was placed on the more recent literature, but late 1981 papers are probably underrepresented. There is also little doubt that we have failed to include some valuable material found in project reports, oral presentations, masters these, disserations, and similar sources. Certainly some citations were not optimally summarized or categorized, particularly when it was necessary to work from an abstract or summary. Hopefully, such exclusions or poor representations will not result in loss of excessive information or unduly mislead the users. We plan to update the matrix periodically, supplementing new information found with the searching techniques developed thus far and especially with information supplied by users. Updates will be in the form of looseleaf pages to be added to or substituted in Volumes I and II, and will be published as frequently as deemed necessary to cover developments in the subject areas. We would very much appreciate receiving copies (or summaries) of pertinent reports from the users of this matrix, together with corrections or improvements in the content or categorization of material presently in the matrix. There should be sent to: F.J. Post (coal) or Jay Messer (oil shale and tar sands) Utah Water Research Laboratory UMC 82 Utah State University Logan, UT 84322 They will be gratefully included in the next update

An Introduction to Trenchless Technology Piping (+Türkçe Özet)

The first reason for the preparation of this book is to share recent developments experienced in underground infrastructure technology with readers. It is the fact that innovative methods are becoming main route in underground piping constructions, renevations and rehabilitations. The second reason is to give awareness of trenchless technology in civil engineering and environmental engineering societies and world communities as well as the Turkish community. The development of new equipment and method and increased level of equipment sophistication and capabilities are driving forces of trenchless technology. A safe and successful trenchless project depends on skills, training and experience of operators, field personal and project inspectors. This book will be of use for all parties in a trenchless project as it provides planning, design, construction, inspection and project management concepts

Thermo-hydro-mechanical simulation of a generic geological disposal facility for radioactive waste

Geological disposal is required for the safe and long-term disposal of legacy radioactive waste. High level waste and spent fuel generate significant heat that will cause thermo-hydro-mechanical coupled processes in the rock mass. The thermal expansion of the fluid will be greater than the grains causing a decrease in mean effective stress with the low permeability restricting Darcy flow and excess pore pressure equilibration. A decrease in mean effective stress can reduce material strength in granular materials, which may be significant near excavations where differential stress is increased. Microseismic monitoring provides cost effective, non-intrusive and three-dimensional data that can be calibrated with the stress and strain behaviour of a rock mass. However, there is no precedent for the microseismic monitoring of heat-producing radioactive waste. Generic concepts, analogue materials and data from in situ experiments are used to demonstrate the potential for the microseismic monitoring of heat-producing radioactive waste in lower strength sedimentary rocks. A mechanism for early post-closure microseismicity is demonstrated, whereby excess pore pressure decreases the mean effective stress towards yielding in shear. The rock and fluid property uncertainties are ranked according to their contribution to the excess pore pressure. Permeability is found to be important as expected, however, Biot's coefficient is demonstrably more important and yet often overlooked. Furthermore, the microseismic event locations, timings and pseudo scalar seismic moments are shown to have statistically significant relationships with the engineered backfill swelling pressure. Therefore, early post-emplacement microseismic monitoring could provide constraints for the engineered backfill swelling pressure and rock property uncertainties whilst the facility is still operational. Insights could prove timely for adapting the engineering designs, if they are not behaving as expected, in further high level waste and spent fuel tunnels

Nottingham: a geological background for planning and development

This study, carried out between 1987 and 1989, was commissioned by the Department of the Environment and funded jointly by the Department and the British Geological Survey. Its principal aim was to produce a synthesis of geological information relevant to the planning of land use and development in part of the Nottingham area. This report is aimed at those involved in planning and development. The results are presented in a style which, it is hoped, will meet the needs of both those with and without previous geological knowledge. Much of the information is provided on a series of sixteen thematic maps, each of which concentrates on a specific aspect of the geology relevant to the use of land. In addition to the information contained in the report, sources of other more detailed data are indicated

Mining Safety and Sustainability I

Safety and sustainability are becoming ever bigger challenges for the mining industry with the increasing depth of mining. It is of great significance to reduce the disaster risk of mining accidents, enhance the safety of mining operations, and improve the efficiency and sustainability of development of mineral resource. This book provides a platform to present new research and recent advances in the safety and sustainability of mining. More specifically, Mining Safety and Sustainability presents recent theoretical and experimental studies with a focus on safety mining, green mining, intelligent mining and mines, sustainable development, risk management of mines, ecological restoration of mines, mining methods and technologies, and damage monitoring and prediction. It will be further helpful to provide theoretical support and technical support for guiding the normative, green, safe, and sustainable development of the mining industry

Milk plant in Cairo City (Egypt)

Qualifying work: 154 pp., 28 tables, 41 Figure, 3 supplement, 88 sources. INDUSTRY BUILDING, FACILITY BUILDING, DESIGN, TECHNOLOGY AND ORGANIZATION OF WORKS. Object of work - plant for the production of dairy products in cairo city (Egypt). The purpose of the project to design an industrial building, namely a plant, using progressive methods of construction production. Results and their novelty. Selected and substantiated basic design and construction solutions. The calculation of the roof enclosure structures was performed. The design of the construction scheme, the collection and calculation of loads. The calculation of the coating plates, the beams on which they are supported and the columns was calculated. The rational scheme of combination of technological processes is chosen. The project of work execution and corresponding technological maps is developed. The analysis of thermotechnical features of the calculation of the inversion roof was performed. Interconnection with other works - continuation of innovative activity of the Department of Civil Engineering, Geotechnics and Geomechanics of NTU "Dnipro university of technology" in the field of industrial and civil engineering and civil engineering. Scope - industrial engineering construction technology. The practical importance of the work is to increase the technical, economic and cultural-social aspects of industrial construction

Numerical simulation of ground surface subsidence due to coal-bed methane extraction

Coal bed methane (CBM) has gained significant attention as a source of natural gas. CBM recovery is achieved through either primary production or enhanced CBM production, the later of which remains at an infant stage. Primary CBM extraction involves production of CBM reservoir fluids using production wells to facilitate pressure drawdown within the targeted formation. De-pressurization is required to release adsorbed methane within the interior surface of the coal matrix. However, de-pressurization can cause compaction within the CBM reservoir, especially in the vicinity of production wells. This, in turn, can lead to ground surface subsidence. The objective of this project is to develop a semi-analytical solution to explore ground surface subsidence above CBM extraction wells. To achieve this, an existing analytical solution, for ground surface subsidence above a cylindrical uniform pressure change, is extended to allow for a non-uniform pressure distribution using the principle of superposition. The non-uniform effective pressure to drive the semi-analytical solution for ground surface subsidence is derived from a numerical fluid flow model describing water and methane production from a CBM formation, also developed as part of this project. The numerical fluid flow model describes two-phase fluid flow (gas and water) in porous media in conjunction with non-equilibrium gas adsorption and stress dependent porosity and permeability. The resulting set of partial differential equations is solved using the method of lines by discretising in space using finite difference and then solving the resulting set of coupled non-linear ordinary differential equations (ODE) using MATLAB's ODE solver, ODE15s. The numerical fluid flow model was verified by comparison with published modeling results from the literature. As a further verification, the model's ability to simulate field production and pressure data was demonstrated using field data from a CBM case study in the US. The potential role of initial water saturation on ground surface subsidence was investigated by studying the associated spatial distributions of fluid pressure. It was found that, for a given time, the mean fluid pressure within the reservoir reduces with increasing initial water saturation. However, the spatial distribution of fluid pressure, for a given volume of produced gas, was found to be insensitive to initial water saturation. This can be attributed to the fact that the volume of water stored in the cleats of the coal-bed is very small as compared to the volume of gas stored within the coal matrix. Consequently, the presence of water in the cleats was found to have no influence on ground surface subsidence for a given gas production volume. It was also found that ground surface subsidence for a given gas production volume is insensitive to initial coal permeability and cleat volume compressibility. A simplified analytical solution for ground surface subsidence was derived assuming that the pressure distribution within the reservoir is uniform. Sensitivity analysis showed that the simplified analytical solution is effective at predicting ground surface subsidence for a given gas production volume, predicted by the numerical model, for all of the scenarios studied. This suggests that pressure distribution within a CBM reservoir is not important for determining ground surface subsidence in this context

Scaling relationships of global river deltas

River deltas are home for ~300 million people worldwide and are hotspots for biodiversity. In recent decades, river deltas have been facing growing stressors due to dams and reservoirs, sand mining and sea-level rise, putting the human and natural systems that rely on river deltas at considerable risk to land subsidence, inland and coastal flooding, and other socially impactful geomorphological changes. The geomorphic response of river deltas to these growing stressors depends on the geomorphic controls on delta morphology and their scaling relationships. However, our current understanding of delta’s geomorphic response to these forcing is limited to local cases, fragmented physical and numerical delta experiments, and simplified global models. In this thesis, I explore the possibility of adopting scaling relationships originally developed for quantitative watershed analysis of fluvial systems to river delta systems to understand deltas’ morphodynamic response towards these stressors. Chapter 1 introduces the challenges faced by modern and ancient river deltas along with the scaling relationship theory. Chapter 2 details the methods used in this thesis, including modern delta observation, numerical modelling and characterisation of ancient delta deposits. Chapter 3 introduces a novel globally consistent scaling from 114 modern river deltas using satellite imageries observation, solving previously debated avulsion scaling. I found that slope break and avulsion location scale consistently, opens potential insights into how delta naturally respond to the growing stressors and how the avulsion mobility is closely tied with slope break, that are imperative for understanding delta flood risk. Chapter 4 investigates the role of the novel scaling found in Chapter 3 in controlling avulsion-bifurcation timescale and interaction in river deltas using numerical model. Avulsion is primarily controlled by delta topset slope, in which it occurs simultaneously with bifurcation process. In Chapter 5, novel palaeodischarge estimation models are proposed by correlating water discharge with delta channel widths and catchment areas from modern global deltas by adopting hydraulic geometry concept. These simple and rock-record focused correlations produce palaeodischarge estimates within the same order of magnitude as the palaeodischarge derived from existing, more complex approaches. In Chapter 6, I reclassified palaeodischarge models built in Chapter 5 based on the marine influence that affects the hydraulic geometry assumption used in earlier models. By establishing more detailed scaling relationships, I found that estimating discharge using hydraulic geometry concept is only applicable for river- and wave-dominated deltas, but not for tide-dominated deltas. Finally, Chapter 7 synthesises the previous chapters and proposes further works