Download or read book Dynamic Properties of Fine Coal Refuse written by Karen Ann Willis and published by . This book was released on 1991 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cyclic Behavior of Fine Coal Refuse and Seismic Stability of Coal Tailings Dams written by Sajjad Salam and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Coal has been one of the main sources of energy in the world. The coal waste that is produced through coal extraction and processing is typically stored in form of slurry in tailings impoundments. The static and dynamic stability of these impoundments are of great importance, as their failure can result in significant spill, loss of human lives, and damages to the environment and infrastructure. The main objectives of this research were to (1) characterize the static and dynamic geotechnical properties of fine coal refuse (FCR), (2) investigate the cyclic behavior and liquefaction resistance of FCR and influencing factors such as strain history and aging, and (3) numerically assess the seismic stability of coal tailings dams incorporating the heterogeneity on FCR deposit in the field. To characterize the static and dynamic geotechnical properties of in situ FCR samples, representative FCR samples were taken from two coal slurry impoundments in the Appalachian coalfields in the USA. Standard penetration tests (SPT) were conducted in the field. Index properties, hydraulic conductivity, and classification of FCR were determined. Staged triaxial tests under consolidated undrained (CU) state and consolidated drained (CD) state were conducted to assess short-term and long-term shear behavior of FCR, respectively. Torsional resonant column tests were performed to determine shear stiffness properties of FCR. Cyclic direct simple shear (DSS) tests followed by static shearing were adopted to evaluate the cyclic and post-cyclic behavior of FCR under various cyclic stress ratios (CSR). To overcome the shortcomings of element testing methods, large-scale shake table testing was conducted. Furthermore, the effects of strain history and short-period aging on cyclic response and liquefaction resistance of FCR were investigated. The FCR specimen was slurry-deposited in a membrane-lined laminar shear box (LxWxH: 2.29 m x 2.13 m x 1.4 m). The FCR specimen was subjected to three shaking events. Instruments including piezometers and linear variable differential transformers (LVDTs) were used to measure the FCR's dynamic response during shaking. A piezocone penetrometer (CPTu) was used to measure soil resistance and estimate cyclic behavior of the FCR specimen before and after each shaking test for time intervals up to 97 days. The cyclic behavior, liquefaction resistance, aging rate, and strength gain within the FCR were studied and compared with those of clean sands. Dynamic loadings such as earthquakes and blasting are among the main threats to the stability of tailings dams. Seismic stability analyses of tailings dams are further challenged by the uncertainty and variability of tailings properties. The influence of input motion characteristics and spatial variability in coal tailings (CT) properties on the seismic stability of a typical upstream-construction CT dam was investigated. First, the applicability of two advanced constitutive plasticity models, PM4Sand and PM4Silt, in simulating the cyclic behavior of CT was evaluated and a suitable model was selected. The undrained shear strength of CT was modeled as a spatially correlated Gaussian random field. Six input motions representing a variety of peak ground accelerations (PGA), equivalent number of cycles (ENC), and frequency content were selected for the dynamic analyses. The seismic stability of the CT dam with uniform properties (i.e. uniform models) was compared to the stochastic models. The uncertainty in seismic response of the studied dam caused by spatial variability in geotechnical properties was investigated. The necessity of post-seismic stability analysis in CT dams was discussed. The influencing factors on the seismic stability of CT dams were also characterized.

Download or read book Physical Property Data on Fine Coal Refuse written by and published by . This book was released on 1975 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geotechnical Properties and Flow Behavior of Coal Refuse Under Static and Impact Loading written by Hao Yu and published by . This book was released on 2015 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: Millions of tons of coal refuse are produced every year and need to be stored in the coal waste tailings dams. Since the impounded fine coal refuse has high water content and low shear strength, the tailings dams is susceptible to the flow failure under static and dynamic impact loading. In some other cases, the coal slurry might break through into the adjacent or underground mines and thereafter flow into the groundwater resources and river ecosystems. It has been known that flow failure of coal waste tailings dams would cause severe property damage, loss of human lives, and environmental issues. Without adequate information and measurement techniques, there is no comprehensive study reported on the properties and flow behavior of impounded coal refuse as well as the failure mechanism. In this study, a comprehensive investigation was carried out on the geotechnical properties and flow behavior of impounded coal refuse under static and impact loading by using a range of laboratory tests, small-scale model tests, and centrifuge model tests. The combined results would help to better understand the flowability of coal refuse and the failure potential of tailings dams. In addition, a potential countermeasure was proposed by using slurry cells. Its effectiveness in reducing the risk of flow failure was evaluated in centrifuge model tests.

Download or read book Physical Property Data on Fine Coal Refuse Fine Coal Soil and Water written by and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physical Property Data on Fine Coal Refuse written by and published by . This book was released on 1975 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physical Properties of Western Coal Waste Materials written by Ronald R. Backer and published by . This book was released on 1977 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Engineering Properties of Combined Coarse and Fine Coal Wastes written by Bill M. Stewart and published by . This book was released on 1981 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Consolidation Characteristics of Fine Coal Refuse written by Gamini C. Weeratunga and published by . This book was released on 1988 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thickening Fine Coal Refuse Slurry for Rapid Dewatering and Enhanced Safety written by Bill M. Stewart and published by . This book was released on 1986 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Liquefaction of Fine Coal Refuse written by David Glenn Hacker and published by . This book was released on 1990 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fundamental Study for Improvement of Dewatering of Fine Coal refuse written by Shio-Hung Chiang and published by . This book was released on 1984 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of the Use of Coal Refuse Fly Ash Compositions as Highway Base Course Material written by Paul V. McQuade and published by . This book was released on 1980 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Challenges in Fine Coal Processing Dewatering and Disposal written by Mark S. Klima and published by SME. This book was released on 2012 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coal mining and preparation have had a long history in the United States and the world, serving as the engine of growth for many industries. Today, new sources of energy, increased environmental awareness, and more stringent regulations from the U.S. Environmental Protection Agency and other organizations are changing the way coal is found, extracted, and used. As a result, fine coal cleaning, dewatering, and refuse disposal are now at a major crossroads. The increased level of fines, and near-density material in the inferior seams being mined today, necessitates the development of more efficient fine coal cleaning devices. This in turn requires improvements in traditional dewatering techniques to address the need for acceptable moisture levels in plant products. Moreover, the larger volume of fine refuse being generated, coupled with harsher disposal regulations, requires upgraded treatment options. This book is a compilation of information presented at the 2012 Fine Coal Symposium, sponsored by the Coal Preparation Society of America; the Pittsburgh Section of the Society for Mining, Metallurgy, and Exploration, Inc.; and the Pittsburgh Coal Mining Institute of America. Provided by international coal companies, major research organizations, technology developers, and industry leaders, the information includes both general knowledge and in-depth discussion on the current challenges facing the industry, techniques for designing more efficient plants, and new cleaning and dewatering technologies. The book is a practical yet cutting-edge resource for plant designers, engineers, and other practitioners, and for university students and faculty.

Download or read book Thickening Fine Coal Refuse Slurry for Rapid Dewatering and Enhanced Safety written by Stewart. Bill M. and published by . This book was released on 1986 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Physical and Chemical Properties of Coarse Coal Refuse from Southwest Virginia written by Barry Robert Stewart and published by . This book was released on 1990 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fine Coal Refuse Slurry Dewatering written by Ronald R. Backer and published by . This book was released on 1981 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: