Geological Engineering Commons^™

Effects Of Vegetation On Slope Stability: A Review, Roberto José Marín Sánchez, Juan Pablo Osorio

Articles

Slope stability is usually affected by factors that reduce soil strength and increase driving forces acting on the slope material, sometimes generating mass movements. Among these factors, vegetation has an important role related to hydrological (e.g. evapotranspiration and infiltration) and mechanical (e.g. tree surcharge and root reinforcement provided by trees) mechanisms. In this review, vegetation influences associated to slope stability are identified, describing the mechanisms involved in the occurrence of mass movements. Finally, the way these factors affect slope stability is explained according to soil properties, climatic conditions and environmental characteristics.

Fate And Impacts Of Priority Pollutant Metals In Coal Fly Ash–Soil–Switchgrass Plant Mesocosms, Olushola M. Awoyemi, E. Kudjo Dzantor

Coal Combustion and Gasification Products Journal Archive

Coal fly ash (CFA) is a coal combustion by-product containing heavy metals (HMs) that can enter and accumulate in environmental matrices. The current study assessed the fate and effects of HMs contained in CFA on Armour silt loam (ASL) soil, switchgrass plant, and leachate. Soil impact indices compared levels of HMs in the CFA-soil admixtures to control soil (without CFA). These indices include contamination factor (*C*~f~), modified degree of contamination (m*C*~d~), and pollution load index (PLI). The ratio of the levels of HMs in switchgrass root and shoot tissues to their levels in the CFA-soil admixtures were used to determine …

Geopolymerization Of Coal Ash To Produce Cementless Binders, Hamid Akbari, Robert Mensah-Biney, Jonathan Simms

Coal Combustion and Gasification Products Journal Archive

The main objective of this study was to evaluate geopolymer concrete made from coal combustion by-products, disposed of in landfills, as a potential substitute for the ordinary Portland cement (OPC), which is responsible for 5-8% of the total CO2 emissions in the world. In this study, a coal fly ash sample from the Carolinas was used in a chemical process known as geopolymerization to produce a “geopolymer” binder. The developed geopolymer binder could competently substitute the OPC binder in regular concrete applications. An experimental design program was conducted to optimize parameters of the geopolymerization affecting the strength of the final …

Groundwater Monitoring And Data Analysis Under The Coal Combustion Residuals Rule, Bruce Hensel

Coal Combustion and Gasification Products Journal Archive

No abstract provided.

Ponded And Landfilled Fly Ash As A Source Of Rare Earth Elements From A Kentucky Power Plant, James C. Hower, John G. Groppo, Kevin R. Henke, Uschi M. Graham, Madison M. Hood, Prakash Joshi, Dorin V. Preda

Coal Combustion and Gasification Products Journal Archive

Twenty samples, with one composite sample built out of the 20 individual samples, of ponded ash were collected at a Kentucky power plant. The coal feed throughout the history of the power plant was central eastern Kentucky low- to moderate-S high volatile A bituminous coal. The pond was in the process of being excavated, with the ash moved to a landfill on another company property. In spite of the long history of the pond and the expected variation in coal supply, and perhaps because of the mixing due to the excavation, there is little variation in ash-basis rare earth elements …

Rare Earth Element Distribution In Fly Ash Derived From The Fire Clay Coal, Kentucky, Madison M. Hood, Ross K. Taggart, Ryan C. Smith, Heileen Hsu-Kim, Kevin R. Henke, Uschi Graham, John G. Groppo, Jason M. Unrine, James C. Hower

Coal Combustion and Gasification Products Journal Archive

Fly ash was collected from individual mechanical and electrostatic precipitator (ESP) hoppers at a 130-MW pulverized-coal utility unit burning a southeastern Kentucky moderate- to high-S Pennsylvanian Fire Clay coal. The fly ash particle size is generally similar within each row of the mechanical and ESP hoppers, with the mean particle diameter decreasing from >36 μmin the mechanical hoppers to 6 μm in the last ESP row. Rare earth element (REE)–bearing phases occur within fine minerals and, possibly, as part of the fly ash glass phase. Transmission electron microscopy was used to identify Y-Ce-Nd-La–bearing regions within a glassy matrix. Y- and …

The Relative Impact Framework For Evaluating Coal Combustion Residual Surface Impoundment Closure Options: Applications And Lessons Learned, Ari S. Lewis, Andrew B. Bittner

Coal Combustion and Gasification Products Journal Archive

In response to the U.S. Environmental Protection Agency’s new rule regarding the disposal of coal combustion residuals (CCRs), many utilities need to re-examine their waste disposal practices and make decisions regarding if and how unlined surface impoundments (SIs) should be closed. The two primary options for closing SIs are in-place closure, with capping and engineering controls, and excavation of the CCR for transport to and re-disposal in a lined landfill. To help inform closure option decisions, we supported the Electric Power Research Institute’s development of a practical, science-based decision framework that comprehensively evaluates the potential impacts to human health and …

Assessment Of Rockfall Rollout Risk Along Varying Slope Geometries Using The Rocfall And Crsp Software, Mariam S. Al E'Bayat

Masters Theses

"Most routes in mountainous areas suffer from rock falling, rolling and bouncing risk. There are many computer programs concerned with simulating the rockfall problem, and whereas they have the same purpose, they however differ in the input data that's needed to simulate the problem, and they also differ in the way of processing and kind of output.

This study used Rocfall® and the Colorado Rockfall Simulation Program (CRSP®) to simulate sixty-three models of varying slope geometry, where only the slope geometry is changed with the same material properties for both the slope and the rocks.

Both programs were fast and …

The Use Of Ceramic Water Filters Under Pressure In An In-Line Water Pumping System, Travis Dean Gardner

Masters Theses

"Ceramic pot filters (CPFs) have proven an effective point of use (POU) filter due to their relative low cost, ease to manufacture, and effectiveness at treating contaminated water. These filters are used by individual homes, and sometimes multiple filters are needed for each home in order to produce enough water for the family's household. If these filters could be used in-line with a pumping system or elevated storage tank, water could be filtered and used on demand for a community in an economically feasible way. However, CPFs are too fragile to use under pressure due to the weak points where …

Imaging In Karst Terrain Using The Electrical Resistivity And Multichannel Analyses Of Surface Wave Methods, Ragab W. Jaafar

Masters Theses

"Electrical resistivity tomography and multi-channel analyses of surface waves data were acquired at a study area in Phelps County in the south-central part of Missouri. The objectives of the investigation were fourfold: 1) to image the subsurface in the study area to a depth of 70 feet; 2) to compare the ERT images generated using both the dipole-dipole and Wenner-Schlumberger arrays; and 3) to assess how variations in the MASW array configuration affected MASW data quality; and 4) to compare the ERT-estimated depth to top-of-rock and the MASW-generated depth to top-of-rock.

The subsurface in the study area was imaged to …

In-Situ Assessment Of Concrete Bridge Decks And Pavements Using Stress-Wave Based Methods, Mengxing Li

Doctoral Dissertations

"Concrete infrastructure of United States is aging and deteriorating. Accurate assessment the condition of concrete infrastructure is critical for its maintenance and rehabilitation. Stress-wave based methods, including ultrasonic surface wave (USW) and impact echo (IE), are becoming popular for characterizing defects and mechanical properties of concrete infrastructures. In this dissertation, a comprehensive literature review of seismic wave theory and common types of defects identified in concrete infrastructures, as well as stress-wave based methods used for concrete infrastructure monitoring and characterizing on a selected concrete bridge deck and two concrete pavement segments are present. The utility and reliability of both methods …

Evaluation Of Slope Stability Quantifying The Effect Of Vegetation, Roberto José Marín, Juan Pablo Osorio

Conference papers

The present study evaluates the shallow landslides susceptibility triggered by rainfall by means of multiple numerical simulations. The simulations integrate a transient rainfall infiltration model with an infinite slope stability model, both of them developed for unsaturated soils in a basin scale. TRIGRS’ infiltration model is used to calculate pore water pressure. The geotechnical model includes the evaluation of two parameters related to vegetation: root reinforcement and tree surcharge due to the weight of the vegetation. These simulations were carried out using multiple values of these parameters so that their behavior is analyzed for the topographic conditions of the watershed …

Developing The Greatest Blue Economy: Water Productivity, Fresh Water Depletion, And Virtual Water Trade In The Great Lakes Basin, A. L. Mayer, Stanley Mubako, Benjamin L. Ruddell

Michigan Tech Publications, Part 1

The Great Lakes basin hosts the world's most abundant surface fresh water reserve. Historically an industrial and natural resource powerhouse, the region has suffered economic stagnation in recent decades. Meanwhile, growing water resource scarcity around the world is creating pressure on water-intensive human activities. This situation creates the potential for the Great Lakes region to sustainably utilize its relative water wealth for economic benefit. We combine economic production and trade datasets with water consumption data and models of surface water depletion in the region. We find that, on average, the current economy does not create significant impacts on surface waters, …

Characteristics And Composition Of Magnetic Concentrates Of Bottom Ash Samples From Two Types Of Thermal Power Plants In Odisha, India, Subir Kumar Das

Coal Combustion and Gasification Products Journal Archive

Aluminosilicate bottom ash samples were examined from a thermal power plant in Talcher (sample NT-BA) and in Sambalpur (sample HR-BA), Odisha, India, to determine magnetic particle morphology, internal structure, mineralogy, mineral chemistry, ash fusion temperature, chemical composition, and leaching characteristics. The Talcher plant has adopted pulverized coal combustion, whereas the Sambalpur plant uses circulating fluidized bed combustion boiler technology. For NT-BA, most magnetic particles were ideal solid spheres (ferrospheres) with diverse morphological features (smooth, granular, dendritic and skeletal, porous, spotted, polygonal, and hollow [magnetite cenospheres]). For HR-BA, magnetic particles were subspherical, oval, and angular and showed widely varying surface morphologies, …

Distribution Of Uranium And Other Radionuclides In Coal And Coal Combustion Products, With Discussion Of Occurrences Of Combustion Products In Kentucky Power Plants, James C. Hower, Shifeng Dai, Greta Eskenazy

Coal Combustion and Gasification Products Journal Archive

Uranium and thorium are part of the mineral assemblages within coals. Uranium can also occur in organic associations, particularly in low-rank coals. While the average U concentration in coals is 2.9 ppm for low-rank coals and 1.9 ppm for bituminous and higher rank coals, high concentrations are known from certain low-rank and thin coals and from coals in areas associated with U mineralization. No high-U coals are mined for power production in the United States. Uranium and Th in coal combustion products are found in amounts more or less in proportion to their concentrations in the feed coal. Not being …

Carbon Dioxide Adsorption Studies On Fly Ash Zeolites, Denitza Zgureva

Coal Combustion and Gasification Products Journal Archive

In this study, the potential of fly ash zeolites (FAZ) Linde (LTA) and faujasite (FAU) to adsorb carbon dioxide (CO2) was investigated in view of the results of implementation in postcombustion carbon-capture technologies. Adsorption isotherms of selected samples were measured at 273.15 K by a Micromeritics Tristar II 3020 surface analyzer. The highest adsorption capacity was obtained for FAZ with a FAU structure synthesized by a two-stage fusion hydrothermal process from fly ash (FA) that was composed of 65 wt% amorphous components. The adsorption capacity for this sample reached a value of 136.40 mg CO2/g FAZ at atmospheric pressure, a …

Analysis Of Scientific Investigations Related To Reclamation Of Surface Mining Control And Reclamation Act Permitted Coal Mines With Coal Combustion By-Products, Kimery C. Vories

Coal Combustion and Gasification Products Journal Archive

In the United states, the placement of coal combustion by-products (CCBs) (i.e., fly ash, bottom ash, boiler slag, flue gas desulfurization material, and fluidized bed combustion material) in coal mines has been an area of controversy. Federal and state governments, universities, the National Energy Technology Laboratory, and industrial research organizations have taken an active role in encouraging and promoting technological advances, research, and technology transfer related to the use of CCBs at coal mines. CCBs have been placed at Surface Mining Control and Reclamation Act of 1977 (SMCRA) permitted mines since 1977 to serve the following purposes: (1) a seal …

Coal Ash By-Product From Shanxi Province, China, For The Production Of Portland–Calcium Sulfoaluminate, Tristana Y. Duvallet, Thomas L. Robl, Kevin R. Henke, Yongmin Zhou, David Harris

Coal Combustion and Gasification Products Journal Archive

Twenty bulk samples were collected from ponded coal combustion ash in Shanxi Province, China, as part of an investigation of their beneficiation potential. The samples were shipped to the University of Kentucky, where they were chemically analyzed. The samples were highly consistent in chemistry, falling within the ASTM C-618 class F compositional range. The particle size of the ponded ash was relatively coarse, with only ,7% by weight on average, falling below 200 mesh (75 mm) particle size. The bulk of the material (.80%) was within 50 by 200 mesh (equivalent to 300 by 75 mm). X-ray diffraction investigation combined …

Effect Of Coal Fly Ash Leachate On The Bioluminescence Intensity Of Vibrio Fischeri, Shiro Ikeda, Irena Kostova, Hideaki Sekine, Yoshika Sekine

Coal Combustion and Gasification Products Journal Archive

Coal fly ash is a residue of coal-fired thermoelectric power plants (TPPs) and is mostly dumped in ash ponds or landfill sites, even though it potentially contains significant amounts of water-soluble hazardous contaminants. Bioassay using the bioluminescent bacterium *Vibrio fischeri* is known to be applicable for assessing the short-term and sublethal toxicity of complex mixtures without the need for precise chemical characterization. However, this type of bioassay is potentially adversely influenced by the pH-induced protein denaturation of cells. Because coal fly ash leachates often have alkaline or acidic properties, when applying the *V. fischeri*-based bioassay to the samples, we need …

Influence Of Coal-Fired Power Plant Emissions Regulations And Consequent Engineering Controls And Coal-Supply Modifications On Fly Ash Chemistry And Petrology: Examples From Kentucky Power Plants, Madison M. Hood, John G. Groppo, Michelle N. Johnston, James C. Hower, Herek L. Clack, Diego S. De Medeiros, Silvio R. Taffarel, Cesar M.N.L. Cutruneo, Luis F.O. Silva

Coal Combustion and Gasification Products Journal Archive

The chemistry and petrology of fly ash are controlled by a number of factors: (1) chemistry of the feed coal (and added fuels, such as petroleum coke, tires, biomass, etc.), (2) particle size of the fuel feed (controlled by pulverized fuel vs. cyclone combustion, maintenance of pulverizers, etc.), (3) design of the boiler and pollution-control system, and (4) temperature of the flue gas at the collection point. In general, for any electrostatic precipitator or baghouse system, the concentrations of volatile trace elements in fly ash will increase with a drop in the flue gas temperature and a decrease in the …

Imaging Reinforced Concrete: A Comparative Study Of Ground Penetration Radar And Rebarscope, Abhishek Kodi

Masters Theses

"Geophysical techniques have been playing a very vital role in subsurface imaging in the recent past. Technology has been making it both reliable and convenient to utilize non-destructive geophysics techniques like Ground Penetration Radar, Induction current based Rebarscope, Seismic methods, ERT, etc. The applications range from shallow subsurface investigation of Bridge decks to old tunnels, mapping of rabars in a pre-existing construction and analyzing the concrete strength.

The thesis constitutes of a comparative study and analysis of a Ground Penetration Radar system and a Rebarscope. Individual parameters obtained directly from the study and obtained indirectly from the study shall be …

Caracterización De Las Propiedades Indices De Los Flujos De Lodos En 3 Km2 De La Ladera Oriental De La Ciudad De Medellín, Juan Camilo Viviescas, Juan Pablo Osorio

Conference papers

La caracterización de las propiedades índices de los geomateriales es una de las labores más importantes en la ingeniería geotécnica, al ser estos un insumo fundamental para la identificación y determinación de propiedades geomecánicas de los suelos. Las principales propiedades índices estudiadas en la geotecnia son el contenido de agua, los límites de Atterberg, la granulometría, el peso unitario y la gravedad específica, las cuales son la base para clasificación de suelos. En este artículo se presenta el análisis estadístico de las propiedades índices de suelos tipo flujo de lodos de la ladera oriental de Medellín, a partir del análisis …

Propiedades Geotécnicas De La Turba Intervenida Antrópicamente, Juan Pablo Osorio

Conference papers

La intervención antrópica en turberas genera cambios significativos en las propiedades geotécnicas de un material orgánico, altamente compresible y con baja resistencia al esfuerzo cortante. Existen diferentes formas de intervención, dependiendo de las tradiciones de cada lugar. Sin embargo, los procesos de intervención más comunes son la precarga por medio de terraplenes y el drenaje, las cuales generan una reducción en el contenido de humedad, la compresibilidad y la permeabilidad, así como un incremento en la resistencia al esfuerzo cortante. En el presente artículo, se discute el efecto de la intervención antrópica en las propiedades geotécnicas de las turbas, a …

Multistage Concentration Of Cenospheres In Fly Ash Using The Inverted Reflux Classifier, A. Kiani, J. Zhou, K.P. Galvin

Coal Combustion and Gasification Products Journal Archive

Cenospheres are one of the most valuable components found in the fly ash waste of coal-fired power stations, consisting of hollow, aluminosilicate spherical shells and offering very low bulk density, high strength, and high thermal resistance. Although wet processing methods offer the best prospect for achieving recovery and concentration of the cenospheres, significant impediments remain for achieving satisfactory economics. This work was concerned with the recovery and concentration of cenospheres from fly ash using a novel system, the inverted reflux classifier (IRC), covering single and multistage processing. The system consists of a series of parallel inclined channels mounted underneath an …

Strengthening Black Cotton Soil With Fly Ash And Moorum: An Investigation Of The Role Of Subgrade And Subbase Layers, Gourav Saxena, Nikhlesh Chaurasia

Coal Combustion and Gasification Products Journal Archive

One of the most effective and economical methods to strengthen clayey soils is addition of stabilizing agents such as fly ash to the soil. In this study, highly plastic clay was stabilized using fly ash. Geotechnical properties such as Atterberg limits, unconfined compressive strength (UCS), and the California bearing ratio (CBR) value of virgin black cotton soil and soil treated with fly ash were evaluated. Soil was stabilized with various proportions of fly ash, i.e., at 0%, 10%, 15%, 20%, and 30%. The UCS of black cotton soil–fly ash mixes is found to be at its maximum at 20% fly …

Using Coal Fly Ash In Agriculture: Combination Of Fly Ash And Poultry Litter As Soil Amendments For Bioenergy Feedstock Production, E. Kudjo Dzantor, Ekundayo Adeleke, Vanaha Kankarla, Oluwatosin Ogunmayowa, Dafeng Hui

Coal Combustion and Gasification Products Journal Archive

Increasing fiscal, human, and environmental costs of coal fly ash (FA) management are leading to advocacy for greater beneficial uses of the by-products as soil amendments in agriculture. Greenhouse experiments were conducted in Armour silt loam (ASL) soil that was amended with FA (10%, wt/wt) with and without poultry litter (PL 5 75 mg N/kg). Biomass productivity of eastern gamagrass (GG), a warm-season perennial grass, was measured to serve as complementary biofuel feedstock to switchgrass (SG). FA was obtained from a site at the 2008 ash spill in Kingston, TN. GG and SG were grown individually in 15-cm-wide 3 41-cm-high …

Fabrication And Testing Of Low-Energy Calcium Sulfoaluminate-Belite Cements That Utilize Circulating Fluidized Bed Combustion By-Products, Robert Jewell, Robert Rathbone, Tristana Duvallet, Thomas Robl, Kamyar Mahboub

Coal Combustion and Gasification Products Journal Archive

The utilization of circulating fluidized bed combustion (CFBC) ash to make cement products that provide added value and offset CO2 production is the objective of this research. CFBC burns coal in the presence of a bed of slaked limestone, which effectively absorbs sulfur dioxide (SO2) to form anhydrite (CaSO4). CFBC produces two kinds of spent bed materials, coarse bottom ash and a much finer fly ash. Both of these products are very high in calcium. When properly conditioned, these materials are capable of acting as hydraulic cements, forming both calcium aluminosulfate minerals, most importantly ettringite, as well as calcium-alumina-silica gels, …

Prediction Of The Unburned Carbon Content Of Fly Ash In Coal-Fired Power Plants, Saeid R. Dindarloo, James C. Hower

Coal Combustion and Gasification Products Journal Archive

Prediction of carbon content in fly ash is a valuable index in both designing and optimizing coal-fired boilers. In this study, methods of multiple regression (MR), decision trees (DT), and support vector regression (SVR) were used for prediction of unburned carbon content of fly ash in a 300-MW power plant with a tangentially fired furnace using a low-NOx concentric firing system. Twenty-one boiler operational and coal petrological variables from 21 experiments in a previous benchmark study were used. A variables correlation matrix was used for feature (independent variables) selection in order to reduce the dimensions (number) of input variables from …

Recycling Of Lignite Coal Fly Ash By Its Conversion Into Zeolites, Silviya Boycheva, Denitza Zgureva, Annie Shoumkova

Coal Combustion and Gasification Products Journal Archive

The present study emphasized the conversion of fly ash from lignite coals into zeolites by a double-stage fusion-hydrothermal synthesis. The raw and the converted fly ashes were characterized with respect to their morphology, composition, and crystallinity. The effects of process parameters such as fusion temperature, concentration of the alkaline activator, and the duration of the hydrothermal incubation on the zeolitization process were studied. The experimental results indicate that the fusion temperature does not influence the process mechanism in the range 550–850uC, but it has an acceleration effect. The elevation of the sodium hydroxide/fly ash ratio from 1.6 to 2.0 enhances …

Determining Rockfall Volumes In Three Sites Along Habs Mountain Road In Southwestern Saudi Arabia, Using Lidar Technology, Abdullah Ayed Al-Otaibi

Masters Theses

"The rugged elevated topography is a characteristic feature of the western and southwestern regions of Saudi Arabia. Few arterial roads connect the scattered villages of these regions to major cities, such as Habs Road in Jazan region. Rock fall poses a serious hazard to people, property and animals along the rock cuts of this road. Although no traditional Rockfall studies have previously been applied to this road, accessibility and rock formation shape and structure variability influenced the choice of using Terrestrial Light Detection And Ranging (LiDAR) technology to calculate the volume of rockfall at selected sites along this road.

Software …