Geological Engineering Commons^™

Estimation Of Mechanical Behavior Of Unsaturated Soils From A Soil-Water Characteristic Curve, Lucas Acheampong

Theses and Dissertations--Civil Engineering

The small-strain shear modulus and shear strength are two crucial mechanical behaviors used in the design of geotechnical structures and in the analyses of earth materials subjected to static and dynamic loadings. Traditional testing methods for these parameters are expensive and time-consuming. This research aimed to address these challenges by developing a model based on the inverse relationship between mechanical behavior of unsaturated soils and the soil-water characteristic curve (SWCC). The proposed model integrates a scaling function to align the SWCC with the mechanical property curve. Empirical relationships were established for the scaling function, specifically aligning with the air-entry value …

Prediction Of Final Subsidence Under Dipping Seam Conditions, Ernesto Maldonado Esguerra

Theses and Dissertations--Mining Engineering

The prediction of ground movements due to underground coal mining and their impacts on the surface are essential considerations that numerous researchers worldwide have studied. Most of these studies have focused on developing different analytical and empirical models for predicting and calculating ground deformation indices for flat or gently dipping seams under variable topography. However, a few studies are available on predicting ground movements under dipping seam conditions. Although most inclined coal seams are in China, India, and a few other countries, dipping seam conditions have been encountered in some cases in the US, where the inclination (dip) may be …

Measuring Ground Surface Elevation Changes In A Slow-Moving Colluvial Landslide Using Combinations Of Regional Airborne Lidar, Uav Lidar And Uav Photogrammetric Surveys, Sarah E. Johnson, William C. Haneberg, L. Sebastian Bryson, Matthew M. Crawford

UK CARES Faculty Publications

Slow-moving, chronically destructive landslides are projected to grow in number globally in response to precipitation increases from climate change, and land disturbances from wildfire, mining and construction. In the Cincinnati and northern Kentucky metropolitan area, USA, landslides develop in colluvium that covers the steep slopes along the Ohio River and its tributaries. Here we quantify elevation changes in a slow-moving colluvial landslide over 14 years using county- wide lidar, uncrewed aerial vehicle (UAV) structure-from-motion (SfM) surveys and a UAV lidar survey. Because the technology and quality differ between surveys, the challenge was to calculate a threshold of detectable change for …

Prediction Of Dynamic Subsidence In The Proximity Of Longwall Panel Boundaries, Jesus David Romero Benitez

Theses and Dissertations--Mining Engineering

The development of mining subsidence has a dynamic character, and it is related to the mining rate and a time coefficient. Reliable prediction of dynamic deformations is important when planning to undermine important structures that cannot account for large relative deformations and or large horizontal strains. This thesis discusses subsidence development for a number of points over a retreating longwall panel in the eastern US. The prediction points are at different distances from the excavation rib and, therefore, present a different response in terms of dynamic movements. Final movements, i.e., measurements after the panel was fully extracted, were used to …

Gadolinium Enrichment In Association With The Magnetic Fraction Of 1 Fly Ash: Real Or An Illusion?, James C. Hower, John G. Groppo, Dali Qian, Nicolas J. Briot, Tonya D. Morgan, Shelley D. Hopps, Elizabeth Cantando

Coal Combustion and Gasification Products Journal Archive

Gadolinium, and possibly praseodymium, are relatively enriched in the magnetic 24 fractions of Class F fly ashes from Central Appalachian coal sources. Although the enrichment is 25 evident in the inductively coupled plasma–atomic emission spectroscopy (ICP-AES) 26 determinations of the rare earth content, transmission electron microscopy–energy dispersive x-27 ray spectroscopy (TEM-EDS) examination of the fly ash fails to show the sites of the Gd or Pr. 28 This apparent lack of correlation could be due to the inability of the EDS to detect low 29 concentrations of the rare earth elements definitively; interferences in the analytics, leading to 30 false …

Evidence Of Coal Conversion In The Majuba Underground Coal Gasification Pilot Plant, South Africa, L.S. Mokhahlane, N.J. Wagner, D. Vermeulen

Coal Combustion and Gasification Products Journal Archive

Underground coal gasification (UCG) is a coal conversion method that permits coal resources to be exploited in situ using high-temperature conversion reactions. An understanding of the chemical, mineralogical, and petrographic properties of the coal, and resultant unburned carbon, degasified coal, and ash (minerals) in the UCG gasification zone, is fundamental to determining conversion rates, gas composition, and environmental and groundwater risk assessments. This study aims to provide a mineralogical and petrographic characterization of UCG residues obtained from the Eskom Majuba UCG pilot plant site in South Africa. Samples were selected from a verification borehole (VH3) drilled at the site following …

Low-Density And High-Strength Fracking Proppant Made By High Alumina Fly Ash, Shuqiang Ding, Jinder Jow

Coal Combustion and Gasification Products Journal Archive

High-alumina fly ash is defined to have alumina (Al2O3) content of no less than 40%, according to the Chinese power industry standard DL/T 2297. Specification for resource utilization categorization of fly ash from coal-fired power plant (Standard No. DL/T 2297-2021), and is considered a valuable raw material to replace bauxite for making aluminum, refractory materials, and fracking proppants, etc. A low-density and high-strength proppant, conventionally made with bauxite, has been successfully made by high-alumina fly ash and commercially used in the market. This new high-alumina f ly-ash–derived proppant has some advantages compared with the bauxite-derived proppant: (1) lower raw material …

Petrology, Physicochemical And Thermal Analyses Of Selected Cretaceous Coals From The Benue Trough Basin In Nigeria, S. A. Akinyemi, O. F. Adebayo, B. B. Nyakuma, A. K. Adegoke, O. A. Aturamu, O. A. Olaolorun, A. Adetunji, James C. Hower, Madison M. Hood, A. Jauro

Center for Applied Energy Research Faculty and Staff Publications

Abundant coal resources that were previously neglected due to a crude oil boom need revitalisation and integration into the national electricity mix to address the energy demands of the Nigerian population. Selected coal samples from the Benue Trough sedimentary basin in Nigeria were examined by various techniques, including proximate and ultimate analyses, organic petrography, Fourier transform infrared ray spectroscopy, and thermogravimetric analysis. Based on vitrinite reflectance, the Lafia-Obi (OLB), Garin Maiganga (GMG), Imiegba (IMG), and Okaba (OKB) coals are classified as subbituminous, while the Lamja1 (LMJ1), Lamja2 (LMJ2) and Chikila (CHK) coals are high volatile B bituminous. The Enugu (ENG) …

Separation Of Unburned Carbon From Coal Conversion Ash: Development And Assessment Of A Dry Method, Charlotte J. Badenhorst, Nicola J. Wagner, Bruno R.V. Valentim, Karel S. Viljoen, Ana C. Santos, Alexandra Guedes

Coal Combustion and Gasification Products Journal Archive

Unburned carbon found in coal conversion ash has the potential to be used in a variety of value-added applications. However, it is first necessary to separate the unburned carbon from the rest of the ash phases. This poses challenges due to the relatively low starting carbon-in-ash values (0.4 to 7.8 wt% reported for South African sources), and the high carbon grades (ideally ∼90 wt% carbon) and recoveries that need to be achieved. In this study a dry method for the separation of unburned carbon from coal ash was developed and assessed using fly, bottom, and gasification ash samples obtained from …

Use Of Ponded And Fresh Ashes From China For The Production Of Portland/Calcium Sulfoaluminate Clinkers, Tristana Y. Duvallet, Robert B. Jewell, Anne E. Oberlink, Thomas L. Robl, David Harris

Coal Combustion and Gasification Products Journal Archive

This article summarizes the use of two fly ashes in the synthesis of Portland/calcium sulfoaluminate (OPC/CSA or A/CSA) clinkers. They are from the Shentou second power plant located in the Shanxi Province and from the Zhungeer power plant located in Inner Mongolia, China. The Zhungeer ash was collected dry, and the Shentou ash is from a pond. Their chemical compositions differ highly, especially the SiO2 and Al2O3 contents. The high contents of silica and alumina make both ashes candidates as a partial or total substitute for bauxite, an expensive source of alumina, in the production of OPC/CSA clinkers. These particular …

Conceptual Groundwater Remedial Alternatives At Coal Combustion Residuals Sites†, Herwig Goldemund, Jeffrey M. Ahrens

Coal Combustion and Gasification Products Journal Archive

Groundwater below many basins that have been used to store coal combustion residuals (CCRs) may have concentrations of certain inorganic constituents in excess of applicable regulatory standards. Given that many inorganic CCR constituents are also naturally occurring in the aquifer matrix, their detection may not always be indicative of a release from the CCR unit. Inorganics may be present at elevated levels in groundwater due to natural or background conditions, or due to changes to the aquifer geochemistry resulting from the presence of the CCR basin, which then mobilizes these naturally occurring constituents beneath the CCR unit. Care must be …

Fly Ash Composites, A Step Toward Pond Ash Composites, Kunigal N. Shivakumar, Wade H. Brown, Kazi A. Imran

Coal Combustion and Gasification Products Journal Archive

The study demonstrated that ash composites made from polyurethane and fly ash are able to reduce leaching of coal ash inorganics to less than one-third of the U.S. Environmental Protection Agency’s maximum containment limit even after being exposed to an accelerated water circulation system for 14 months. Even if these ash blocks are broken, the composite is safe. The concept of encapsulation of fly ash into ash composite by using a polar polymer to bind the fine inorganic particles, as nature has done in the original unburned coal, makes the ash composite safe. The ash composites have compression and f …

In Situ Characterization Of Mixture Of Fly Ash And Fluidized Gas Desulfurization By-Product At Tennessee Valley Authority’S Gallatin Ash Stacking Facility†, David J. White, Pavana Vennapusa, Brendan Fitzpatrick, Jason F. Hill, Nicholas Mcclung

Coal Combustion and Gasification Products Journal Archive

This article presents the results of field and laboratory testing performed on a new coal combustion product (CCP) derived from a mixture of fly ash and dry fluidized gas desulfurization by-product at the Tennessee Valley Authority’s Gallatin Fossil Plant in Gallatin, TN. Field testing included geospatial mapping using a vibratory smooth drum roller instrumented with a validated intelligent compaction (VIC) system and by field testing to characterize elastic modulus, shallow shear wave velocity, moisture content, dry density, and shear strength properties. Field testing was performed in areas where the CCP had been placed several days before testing and in areas …

Managing Springs Emanating From Coal Combustion Residual Disposal Impoundments, Mark L. Orzechowski, Daniel M. Tolmer

Coal Combustion and Gasification Products Journal Archive

Affected springs emanating from coal combustion residual (CCR) disposal impoundments where “wet disposal” methods were employed is a typical issue that frequently needs to be addressed during operation and management of these facilities. Identifying potential effects on a spring is typically accomplished through regularly scheduled field reconnaissance and laboratory analyses. Analytical testing is performed to characterize the chemical constituents present in the spring water. The management approach employed for specific springs is developed on the basis of several factors, including chemical composition and flow rate of the spring water, regulatory requirements and discharge standards, available treatment technologies, facility operations, site …

Shear Strength Of Coal Combustion Product By Vane Shear, Wesley J. Herweynen, Christopher A. Bareither, Joseph Scalia

Coal Combustion and Gasification Products Journal Archive

The objective of this study was to evaluate the shear strength of a coal combustion product (CCP) by using the vane shear test. A series of small-scale vane shear (SS-VS; diameter = 12.7 mm and height = 25.4 mm) and large-scale vane shear (LS-VS; diameter = 25 mm and height = 50 mm) laboratory tests were conducted. Undrained and drained strength envelopes were determined using consolidated undrained triaxial compression tests, and drained strength was checked via consolidated drained direct shear. In addition, effects of (1) rate of vane rotation, (2) time delay between vane insertion and beginning rotation, and (3) …

Mineralogy And Geochemistry Of Feed Coals And Combustion Residues From Tunçbilek And Seyitömer Coal-Fired Power Plants In Western Turkey, Ali Ihsan Karayigit, Ozlem Yigitler, Seda Iserli, Xavier Querol, Maria Mastalerz, Riza Gorkem Oskay, James C. Hower

Coal Combustion and Gasification Products Journal Archive

This study focuses on the enrichment of elements in feed coal (FC) and combustion residues, namely, fly ash (FA) and bottom ash (BA) samples, picked up from the Tunçbilek and Seyitömer coal-fired power plants in western Turkey. The FCs in both plants have generally similar mineralogical compositions, although siderite and dolomite are more prominent in Tunçbilek and feldspar and pyrite are more abundant in Seyitömer. Minerals in the FA from both power plants are mainly quartz, hematite, magnetite, anhydrite, and mullite. Along with quartz, the Fe-oxides are dominant phases in the BA samples. Accessory minerals in the FCs, FAs, and …

Phaselous Vulgaris Growth Under The Influence Of Manufactured Coal Ash Aggregates, Sangchul Hwang, Imiraily Hernandez, Isomar Latorre, Sahid Rosado

Coal Combustion and Gasification Products Journal Archive

Manufactured coal ash aggregates (MAs) are a 2:1 (w/w) solidified composite of fly and bottom ash. The current study assessed the feasibility of beneficial utilization of MAs as a subsoil substitute for open-pit restoration to phyto-viable land. A series of indoor and outdoor experiments examined Phaselous vulgaris growth under the influence of MAs in the soil environment. With the MAs layer below the topsoil, P. vulgaris showed enhanced growth with respect to shoot height, leaf number, and leaf chlorophyll intensity. Similar growth enhancement was observed when the MAs were mixed with topsoil or applied as a micronutrient source over the …

Using The Conceptual Site Model To Efficiently And Effectively Implement Groundwater Monitoring And Corrective Action At Coal Combustion Residual Sites†, Carla Landrum, Jim Feild, Tim Glover, Alison Dunn

Coal Combustion and Gasification Products Journal Archive

On 19 October 2015, the Disposal of Coal Combustion Residuals (CCRs) for Electric Utilities final rule (CCR Rule), issued by the U.S. Environmental Protection Agency (US EPA) under Subtitle D of the Recovery and Conservation Act (RCRA), became effective. The Groundwater Monitoring and Corrective Action subsections of the CCR Rule (40 CFR §§ 257.90–257.98) set out strict requirements for groundwater monitoring at the detection and assessment levels, followed by (if necessary) groundwater characterization in support of corrective measures assessment. Since the federal CCR Rule was implemented, the US EPA has proposed and finalized some amendments, and some states have proposed …

The Role Of Ash Mineralogy On Breakthrough Pressure And Contact Angle: A Statistical Evaluation, Jenberu L. Feyyisa, John L. Daniels

Coal Combustion and Gasification Products Journal Archive

One method to minimize contaminant leaching from coal fly ash (CFA) involves modifying its surface to become water repellent. Five types of CFA, CFA-1, CFA-2, CFA-3, CFA-5, and CFA-6, were modified by three organosilane (OS) products at different mix ratios. Multiple breakthrough pressure (BP) experiments were conducted for different samples at different mix ratios to identify the performance of the modified surface to resist a positive water entry pressure. The contribution of oxides and minerals in CFA to form a water-repellent surface were analyzed without considering OS effects. Results showed that semi-log–transformed regression models can effectively establish the relationship between …

South Africa’S Power Producer’S Revised Coal Ash Strategy And Implementation Progress, Kelley Reynolds-Clausen, Nico Singh

Coal Combustion and Gasification Products Journal Archive

The South African electricity public utility Eskom has embarked on a process to increase utilisation of the ash produced through the electricity generation process at its coal-fired power stations. In the 2014–2015 financial year, 119.2 million tons of coal was consumed, producing 34.4 million tons (28.9%) of ash. About 7% of the Eskom ash is sold from 6 of the 13 coal-fired power stations. Many stations are currently running out of ash storage space, and expansion of the ash disposal facilities is required, which could affect security of supply because of limited ashing areas. Additionally, legislative requirements lead to extra …

Effects Of Depositional Processes On Strength And Compressibility Of Sediments Using Elastic Shear Wave Velocity, Wisam Razzaq Muttashar

Theses and Dissertations--Earth and Environmental Sciences

Depositional processes are the most critical, complicated conditions that govern sediment properties and their variations, which in turn significantly affect the geotechnical behavior of the sediment. The complexity of depositional and post-depositional processes, which results in a variety of depositional environments, makes constructing a plausible model for the consolidation process of sediments difficult. The mutual influence between the temporal and spatial variation of depositional environments with their resultant physical and mechanical properties cause several compression issues, such as consolidation settlement and land subsidence, which mostly occur in estuarine-riverine regions throughout the world.

The first aim of this study is proposing …

The Role Of Dense Slurry In Achieving Zero Liquid Discharge, D.M. Timmons, Istvan Kovacsics

Coal Combustion and Gasification Products Journal Archive

The Coal Combustion Residual (CCR) and Effluent Limitations Guidelines (ELGs) rules pose significant technical and economic challenges for ash management and for treatment and discharge of flue gas desulfurization (FGD) wastewater at coal-fired power plants. Beneficial use is always a priority for ash, but only about half is being reused on a national basis, and the rest is destined for disposal. The U.S. Environmental Protection Agency identified biological treatment as the baseline treatment technology for FGD wastewater in the ELGs. However, it is becoming evident that bioreactors exhibit high capital and operating costs, occupy significant space, and are sensitive to …

Compressibility Of Fly Ash Under Ko Loading: Strain Rate Effects In Constant Rate Of Strain Testing, Jaime A. Mercado, Luis G. Arboleda-Monsalve, Tarunjit S. Butalia, Pedro J. Amaya

Coal Combustion and Gasification Products Journal Archive

Coal combustion processes produce large volumes of fly ash. The compressibility of fly ash was studied using moist tamping and drypluviation methods to achieve different void ratios before subjecting the material to compressive oedometric Ko loading (i.e., zero lateral deformation throughout the test). The class F fly ash used in this research was produced at a Midwest U.S. power plant. The material was initially characterized with hydrometer and specific gravity tests, and maximum and minimum realizable void ratios were determined. The compressibility characteristics of the fly ash material were studied at four strain rates, 1%/h, 10%/h, 40%/h, and 100%/h, and …

Influence Of Flow Rate On Leachability, John L. Daniels, Gautham P. Das

Coal Combustion and Gasification Products Journal Archive

The leaching potential of coal fly ash is often approximated with laboratory-based methods that expose columns of compacted material to synthetic precipitation. While this procedure can simulate aspects of the field condition, it remains difficult to replicate site-specific thermodynamic and kinetic constraints on geochemical processes. This article explores one aspect that contributes to the field/laboratory disparity, namely, the influence of flow rate and intermittency. Seven column-based leaching experiments were conducted with the same ash but with different flow rates and intermittency (i.e., infiltration pulsing), and results were evaluated in terms of aqueous sodium, calcium, and chromium concentrations in the effluent. …

Kinetic And Thermodynamic Parameters For The Adsorption Of Methylene Blue Using Fly Ash Under Batch, Column, And Heap Leaching Configurations, J.H. Potgieter, S. Pearson, C. Pardesi

Coal Combustion and Gasification Products Journal Archive

In this article, the use of fly ash, a low-cost adsorbent, for the removal of a toxic cationic dye, methylene blue (MB), from aqueous solution has been investigated. Fly ash is a waste by-product generated from coal combustion. Contrary to many other reported investigations, the fly ash was not treated prior to the experiments for this investigation. The study was done in order to ascertain the viability of using the waste material to remove cationic dyes from wastewater. While MB adsorption has been described often in batch studies, batch, column, and heap leaching studies were carried out under the same …

Universal And Excavatable Controlled Low Strength Material Using High Loss On Ignition Fly Ash And Limestone Screenings†, James T. Locum, L.K. Crouch, Daniel Badoe

Coal Combustion and Gasification Products Journal Archive

Limestone screenings and high loss on ignition (LOI) fly ash are by-products that are stockpiling because of their unintentional production and the negative effects when utilized in portland cement concretes. The research objective was to investigate whether these by-products could produce controlled low strength materials (CLSMs) meeting the three types of Tennessee Department of Transportation (TDOT) 204.06 flowable fill specifications. TDOT defines these CLSMs as the following: general use, excavatable, and early strength. Each type is required to have an inverted slump flow of not less than 15 inches (38.1 cm) while meeting ASTM International D6024 at 24 hours. Because …

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 …