Thesis (M.S.)--Ohio University, June, 1986. / Title from PDF t.p.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 101-115). Also available via the Internet.

Thesis (M.S.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains xi, 322 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 212-217).

Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains xvi, 304 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 129-132).

A research report submitted to the Faculty of Engineering and the Built Environment, School of Mechanical, Industrial and Aeronautical Engineering, University of the Witwatersrand, in partial fulfilment of the requirements for the degree of Master of Science in Engineering. / This study was based on the hypothesis that there are opportunities to maximize production outputs in many existing underground hard rock trackless mining systems using the same or less resources by improvement in decision making paradigms. This is very important in the current operating environments of uncertainties and continued drop in metal prices. The project main goal was thus to carry out a detailed investigation of trackless mining production systems and test how to maximize output by focusing on three objectives, namely: analyzing key technical factors that impact the production rates in terms of tons per hour, identifying major operational activities which impact effective equipment operating hours, and identifying decision support systems (DSS) to improve operational decision making. Regarding the first objective (production rates), through the analysis of trackless mining as a serial production system, it was shown that production rates could be increased by focusing at system level, process level and work station/equipment level decisions. System level decisions must minimize the total residence time of the material (ore) in transit or work in process(WIP). This will open capacity for generating more ore. Process level decisions must reduce the gross cycle times at the work stations to equal or be below the Takt times inorder to smoothen production flow. Takt time is an important factor in a production system which shows the maximum cycle time allowed to meet the daily demand. The third level focuses on the capability of the mining equipment itself through decisions that improves the reliability, maintainability and capacity. Decision tables based on reducing the equipment failure rates (λ), improving the repair rates (µ) and the cycle times were developed to aid in making the reliability, maintainability or capacity decisions. For the second objective (operational activities), the focus is to maximize effective operating times of the equipment through reduction of delays. The study shows this can be achieved through use of real-time decision support systems (DSS) for better control of the operations. The third objective was able to identify functional modern DSS that can be implemented in trackless mining. Effectively, the study was able to highlight opportunities of generating extra capacity for trackless mines at same or less resources by focusing on the above three objectives. / TL2019

Thesis (Ph.D.)--University of Wollongong, 2009. / Typescript. Includes disc in back pocket. Includes bibliographical references: leaf 264-272.

Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains xii, 140 p. : ill. (some col.), maps (some col.). Includes abstract. Includes bibliographical references (p. 120-122).

Both active and residual mine subsidence resulting from underground coal mining have caused surface damage to land and structures. A method of subsidence mitigation successfully used abroad, and to a much lesser extent in U.S. coal mines, is backfilling. In addition to the possible benefits of subsidence mitigation, backfilling has the potential to increase coal recovery, enhance ventilation control, and to minimize mine fires. Backfilling can also be used as a means of mine refuse disposal, provided the refuse is a suitable fill material. A Iiterature review has been made of the various backfilling practices and stowing materials that have been used in both underground hardrock and coal mines. The mechanics of fill support were also reviewed, as well as how the physical properties of a stowing material affect its ability to provide ground support. Based on this review, a testing program was conducted to examine properties of coal refuse which are pertinent to its placement and its ability to act as a ground support material. The testing program consisted of the slake durability test, plasticity test (Atterberg's Limits), grain-size analysis, standard Proctor compaction test, falling-head permeability test, and triaxial compression test. Based on the geotechnical properties of the refuse which was sampled, it was determined to be inadequate as a backfill material. / Master of Science

Surface subsidence is an inevitable consequence of most underground coal mining. The United States Bureau of Mines has estimated that over 3,000 square miles of land in this country have been affected by subsidence, and it is currently estimated that an additional 2,400 to 3,800 square miles will be affected over the next twenty years. Surface subsidence is a complex phenomenon which is influenced by many variables related to both mining and site conditions. Although it cannot be prevented, foreigh experience has shown that it, nevertheless, can be controlled. In order to achieve this goal, however, methods of subsidence prediction and control must be developed for the United States mining conditions and justified with empirical data. The objective of this research is to develop characteristic relationships of longwall subsidence and its related parameters from case studies gathered from the Appalachian coalfields. Furthermore, based on this information, an empirical, predictive capability will be developed which can be used to provide accurate and reliable predictions of subsidence in this region. / Master of Science

Thesis (M.A.)--University of Wyoming, 2009. / Title from PDF title page (viewed on Apr. 12, 2010). Includes bibliographical references (p. 94-98).