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Application of Field Measurements and Computer Modeling to Evaluate Deep Mine Shaft Stability in Northern Idaho

Description: Abstract: Researchers at the U.S. Bureau of Mines have developed personal-computer-based data acquisition, instrumentation, and mine visualization and modeling techniques to evaluate a mine accessway in a deep hard-rock mine in northern Idaho. These techniques were applied to a mine shaft in a large silver mine that has been in operation for many years. A very deep, rectangular, timber-supported shaft extending to depths exceeding 2.3 km (7,500 ft) had been deforming continuously as a result of nearby mining, resulting in operational problems. Preliminary visual observations and rock and support monitoring confirmed that severe diagonal distortion was occurring. Extensive field measurements and data analysis confirmed initial observations, provided insights into the cause of deformation, and defined a general approach to structural modeling. Computer analysis of the problem was initiated by developing a three-dimensional model of the terrain. This represented a volume of rock approximately 80 km3 (40 x 1010 ft) and an area on the surface surrounding the mine 9 km2 (3 square miles). Based on this model, a three-dimensional, finiteelement analysis was conducted to establish boundary conditions for sequentially more detailed two- and three-dimensional submodels of the shaft area. Results from the computer study are being used to develop new approaches to mine design and to provide design guidelines for deep mine accessways subject to severe rock-mass loading conditions.
Date: 1996
Creator: Beus, Michael J.; Orr, T. J. & Whyatt, J. K.

Bending Fatigue Tests on Flattened Strand Wire Rope at High Working Loads

Description: Abstract: The U.S. Bureau of Mines established a wire rope research laboratory to examine the factors that affect the safety and the useful life of wire rope. In the most recent work, two 32-mm 6x27H flattened strand ropes were degraded on a bending fatigue machine. The two tests were run at constant loads of 285 and 347 kN or safety factors of 2.5 and 2. Nondestructive and tensile strength tests were performed on samples of the ropes to determine the relationship between rope deterioration and rope breaking strength. Neither the area loss nor the number of broken wires measured from nondestructive tests could be used as clear indicators of the loss of strength. However, it was found from the tensile tests for both rope specimens that the strength loss was associated with the reduction of breaking strain. This suggests that measuring the strain of many short sections of a rope in the elastic region may locate the high stress sections and thus determine the condition of the rope.
Date: 1995
Creator: Wang, Richard C. & Shapiro, David E.

Beneficiation of Iron-Copper Ores from Kasaan Peninsula, Prince of Wales Island, Alaska

Description: Report issued by the Bureau of Mines over studies conducted on the beneficiation of iron-copper ores. As stated in the summary, "this report summarizes the results of laboratory testing of copper-bearing magnetite ore from the Poorman, Rush and Brown, and Copper Center deposits, Kasaan Peninsula, Prince of Wales Island, southeastern Alaska" (p. 1). This report includes tables, maps, and illustrations.
Date: February 1957
Creator: Wells, R. R.; Erspamer, E. G. & Sterling, F. T.

Beryl Mountain, Sullivan County, New Hampshire

Description: Report issued by the Bureau of Mines over exploration of mineral deposits on Beryl Mountain. As stated in the introduction, "testing by surface cuts, trenching, and tunneling was conducted by the Bureau of Mines from August to December 1943" (p. 1). This report includes maps.
Date: March 1948
Creator: Levin, S. B.

Bituminous-Coal Deposits in the Vicinity of Eska, Matanuska Valley Coal Field, Alaska

Description: Report of investigations issued by the U.S. Bureau of Mines on the estimated recoverable reserves of bituminous coal found in the Matanuska Valley Coal Field. The investigation includes studies of the area, and methods of mining which include diamond and churn drilling. This report includes maps, photographs, and illustrations.
Date: February 1952
Creator: Jolley, Theodore R.; Toenges, Albert L. & Turnbull, Louis A.

Bovill Clay and Sand Deposit, Latah County, Idaho: Geology, Minerology, and Beneficiation Tests

Description: Report issued by the Bureau of Mines on the clay-silica deposits found in Bovill, Idaho. As stated in the abstract, "the geology, mineralogy, beneficiation, and potential uses of the clay and quartz fractions of the Bovill deposit are described" (p. 1). This report includes tables, graphs, photographs, and maps.
Date: 1963
Creator: Kelly, Hal J.; Carter, George J. & Todd, George H.

Briquetting Subbituminous Coal

Description: Report issued by the Bureau of Mines over briquetting of coal for development of more effective fuel. Materials, equipment, and processes are discussed. This report includes tables, illustrations, and photographs.
Date: June 1943
Creator: Parry, V. F. & Goodman, John B.