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By Braden T. Lusk, Rex A. Meyr, Kyle A. Perry

Following three major mining accidents in 2006, the MINER Act of 2006 was enacted by MSHA and required every underground coal mine to install refuge alternatives to help prevent future fatalities of trapped miners in the event of a disaster. A polycarbonate safe haven wall for use in underground coal mines was designed and modeled using finite element modeling in ANSYS Explicit Dynamics to withstand the MSHA required 15 psi (103.4 kPa) blast loading spanning 200 milliseconds. The successful design was constructed in both half-scale and small scales in the University of Kentucky Explosives Research Team’s (UKERT) explosives driven shock tube. The constructed polycarbonate walls were tested multiple times to determine the walls resistance to blast pressure. The results for each test were analyzed and averaged to create one pressure versus time waveform which was then imported into the finite element program and modeled to compare deflections of each part to that was measured during testing for model validation. This paper summarizes the results.

Jan 1, 2014

So many emergencies that crop up in mining necessitate a departure from ordinary methods that the writer has been led to illustrate a few of the examples that have come under his notice during a somewhat lengthy career; and as most of the methods illustrated are certainly outside the ordinary, it may be hoped that while to many they may convey little that is new, to the larger number some acceptable information may be gleaned whenever the occasion calls for it. Experience has shown that there can be no hard and fast rule in mine timbering that will fit the varying- necessities of different localities, and the engineer must divest his mind of all prejudices that his practice of any particular system or systems may have induced, and must direct his attention to the character of the local timber and its fitness or otherwise for the purpose he has in view. Fortunate indeed are the man and mine that can claim an abundance of good and cheap mining timber it simplifies, oftentimes, what would be, under unfavourable timber conditions, a difficult problem. In many parts of the States there is either none or at best a scrub if the latter, he has to either pigstye, balk, or bulkhead, if his ground will permit; if, not, and the necessary timber has to be imported, then some system of recovering his timber and using it over and over again may be possible. As an illustration of this, Fig-s. Nos. I and 2 show a method applied to the copper deposits of the LyellTharsis, Tasmania. The workings were wide; varying from 30 ft. to 50 ft., and the deposit a taIcose schist of fairly good...

Jan 1, 1902

By Christopher Mark

A coal burst is defined as the sudden, violent ejection of coal or rock into a mine opening. Coal mines in the North Fork Valley (NFV) of Colorado?s Gunnison River have a long history of coal bursts in a wide variety of settings. These have included longwall and room-and-pillar, development and retreat, and single- and multiple-seam mining. In contrast to other coalfields, where bursts are typically associated with strong, massive sandstone and extremely high stress, many bursts in the NFV have occurred beneath shale roof and some distance from the most highly stressed locations. The goal of this paper is to attempt a systematic study of the entire burst history in the NFV, in order to gain insight into their characteristics and causes. The primary sources of information are the reports of investigations conducted by the Mine Safety and Health Administration (MSHA) Roof Control Division over the past 15 years. This paper provides details on the geologic mapping conducted as part of these investigations, as well as a regional plot of burst locations using a Geographic Information System. The mapping indicates that many of the NFV bursts have been associated with structural features, including low-angled faults and well-defined zones of high-density jointing that exhibit little or no displacement. Some of these features appear to extend for several miles, impacting more than one mine.

Jan 1, 2012

By Mohamed A. Younis, Paul J. Headland, Paul H. Madsen, Vojtech Gall

INTRODUCTION A 100 ft long, 20 ft high and 18 ft wide NATM tunnel was excavated through grouted clean sands beneath a busy city street, including a variety of existing utility lines. The new tunnel associated with a hospital expansion will serve as a pedestrian tunnel connecting a parking structure with a new hospital facility. Tunnel construction started on December 15, 2005 when drilling for the grouting program started and was completed on May 26, 2006 when the tunnel final lining was completed. The tunnel was constructed by Kiewit Construction Company as a tunnel subcontractor to The Christman Company who is constructing the hospital facility for Spectrum Health in Grand Rapids, Michigan. URS was the project designer. GallZeidler Consultants, LLC were the contractor’s NATM consultant. PROJECT DESCRIPTION The Michigan Street Pedestrian Tunnel is a component of the Michigan Street Development located along the north side of Michigan Street NE between Coit Avenue NE and North Division Avenue in the downtown area of the Grand Rapids, Michigan. The Michigan Street Development includes a parking deck and four new towers to be constructed over the proposed parking deck. The tower planned furthest east is being developed by Spectrum Health as the Lemmen-Holton Cancer Pavillion. The purpose of the pedestrian tunnel is to connect the proposed Lemmen-Holton Cancer Pavillion with the future Spectrum building to be located on the south side of Michigan Street NE. The southern end of the tunnel was constructed with a bulkhead until the future Spectrum building is constructed at which time interconnection will be required. The tunnel site plan and profile are shown in Figure 1, Site Plan, and Figure 2, Tunnel Profile. Several challenges were faced during the design and construction of the Michigan Street Pedestrian Tunnel. These challenges included compressed design and construction schedule, maintenance of traffic and protection of old underground utilities. The tunnel was being constructed as part of the Michigan Street Development and coordination with other concurrent construction activities was required. The tunnel was constructed within a specified window of time to allow other associated construction activities to take place without compromising the overall project schedule. The design started in June 2005 and construction was completed by June 2006.

Jan 1, 2007

By Louis Moyd

In the preparation of illustrations to accompany reports of investigations concerning particle shapes of various natural and manufactured materials proposed for use as fine aggretates in concrete structures, it was found that stereoscopic views of such materials presented the information much more effectively than the usual two-dimensional photographs. With the whole-hearted cooperation of the Photographic Section, a technique was developed in the petrographic laboratory of the Concrete Research Division, U.S. Corps of Engineers, at Clinton, Miss., for simple and rapid preparation of paired stereoscopic photographs and micrographs. The method requires only equipment which is usually part of the general stock of any laboratory, and it is adaptable for all purposes in which three-dimensional views would be found superior to ordinary photographs.

Jan 1, 1949

By R. Stenne

This paper presents the trends in deep foundations in Europe, both in terms of design and construction. Eurocode 7 which is a design code for geotechnical engineering will be introduced in the European Union member countries, and will oblige geotechnical engineers to abandon traditional methods based on a global factor and adopt a new approach based on partial factors of safety. Execution codes (for construction of foundations and other geotechnical processes) are currently being introduced without problems. Ever more demanding environmental constraints push foundation contractors to adapt old techniques and develop new ones to comply with new regulations.

Jan 1, 2000

By David C. Girard, Larry Williamson, Leonard R. Benson, Ronald E. Bizzarri

On the east side of Washington DC, the DC Water & Sewer Authority is developing a Facility Plan for the Anacostia River CSO Control Projects, including 8 to 12 miles of CSO storage/conveyance and flood relief tunnels and associated facilities. The project includes major technical and non-technical challenges, including: completion under a Federal Consent Decree schedule; large diameter (estimated 25 to 35 ft) soft ground tunnels and shafts up to 200 ft depth; operations without use of active flow control systems; and close coordination with several major public and private construction and development projects that are being advanced in the project area.

Jan 1, 2007

By Michael H. Wysockey

The load test program for the pile foundation at Soldier Field included static and dynamic load tests at four locations around the site. The dynamic tests were run with no knowledge of the static results, and comparison between the two is very good. It was necessary to use a special testing hammer (not the production hammer) to demonstrate capacity with dynamic testing. Over 90% of the piles were HP14x89 with a design load of 230 tons (18 ksi). The load tests showed a capacity in excess of 590 tons for all tests where sufficient set up time was allowed. The remainder of the piles were mostly HP 12x53 with a design load of 100 tons (13 ksi). The measured capacity of these piles was typically about 250 tons. One experimental HP12×74 pile with a nominal yield of 65 ksi held 730 tons (67 ksi) before failing.

Jan 1, 2002

By M. Tominaga

An industrial port complex was constructed on the west coast of Leyte Island The work was started in December 1981 and completed in May 1984. This port complex includes a 665 m long wharf and can accommodate vessels ranging from a 60,000 DWT ore carrier to a 4 000 DWT general cargo ship. It now handles materials for and products from a copper smelter with an annual capacity of 130,000 t and a fertilizer plant with an annual capacity of 900,000 t. The Wharf structures consist mainly of interlocked steel pipe piles, steel sheet piles and steel pipe Piles. Material handling equipment such as unloaders, shiploaders, etc. were installed on the wharf. Site survey, planning, engineering design and construction aspects of the port development are discussed in this paper with particular emphasis on the wharf structure.

Jan 1, 2010

By Tom Meikle

Long tendon support systems provide several challenges when used in-cycle as part of the secondary or primary support cycle. A two-component pumpable resin, Carbothix, has been in development for use with self-drilling rock bolts, but many of the attributes of this new resin system make it ideal for grouting long tendon support systems. While neat Portland cement grouts or polyester resin capsules have been used with long tendon support systems for many years, two-component pumpable resin systems overcome many of the shortcomings in these systems. The two-component systems dramatically improve the set-time to enable mining face advance with fewer delays, enable longer pumping distances, improve quality control, and enhance load transfer mechanisms. This paper describes the key benefits associated with a new pumpable resin and details the Australian Department of Mines and Petroleum department atmospheric testing results and cable load testing completed by Minova personnel to date. It also details the results of the Australian mine site trials and the introduction of these systems into production use.

Jan 1, 2012

This paper deals chiefly with the preliminary examination, when a decision has to be made as to whether a prospect has a chance of developing into a mine or not. At this stage it is important to have a fairly clear conception of what is expected of the prospect, andjust what type of mine is sought. Much money can be wasted testing a prospect suitable for a prospector or small syndicate, but which never looked like becoming a mine of sufficient size to interest a company. When undertaking an inspection, therefore, it is necessary to have a broad outline, at least, of the policy of the principals for whom the report is intended.At this early stage it is frequently necessary to form an opinion of the prospects of a property on very meagre data. When new to this type of work one's first reaction is often th~t it is impossible to pass an opinion on the data available. It. is absolutely necessary,however, that an opinion of the possibilities and chances of favourable development be given; The report should strive to convey this information, making quite ::lear the risk involved, how complete are the data on which this opinion is based, and the possible magnitude of the prize. A Preliminary report has to state whether a property has sufficient prospects to warrant testing.The following procedure is suggested in order to make best use of the data and minimise hasty conclusions influenced by preconceived ideas-an ever-present danger.Examination.The first stage is the examination. This should aim at collecting all available significant data, but avoid clouding the issue with detail which, at this stage, will not affect the decision. The following points are considered to be the main ones for which to look:-Geological Environment.As good a working knowledge as possible'of the geology of the area should be obtained. Government Geological Survey reports and maps, if available, will be a big help. A detailed knowledge of the regional geology is not necessary a,t this stage, but a broad outline of the geological setting of the prospect under review, and also of any other important mines in the district, is often helpful in the final decision.The Nature of the Ore-Body.Any facts concerning the nature or occurrence of the lode should be noted as, coupled with experience of similar bodies, they affect the ultimate decision.Structural Control.This is probably the most important factor, in the light of present geological knowledge. Its chief importance is due to two facts:-(a) Structure plays one of the prime parts in ore deposition.(b) Geological knowledge, of structure is somewhat in advance of knowledge of other factors influencing ore deposition.

Jan 1, 1950

By P J. White, J V. Lawless

Low-sulphidation epithermal gold deposits, which form in quasi-hydrostatic convective hydrothermal systems, frequently contain chalcedony within high-grade ore, which has been interpreted to be a crystallisation product of amorphous silica. To deposit amorphous silica rather than another silica polymorph at elevated temperatures requires very high silica concentrations, because of its relatively high solubility. Only extreme boiling caused by decompression followed by wall rock heating upon structural dilation, can achieve this. As gold deposits with amorphous silica it must be produced by the same mechanism, particularly since extreme boiling is also a very effective mechanism for gold deposition. Recent developments support this view; the first is the detailed isotopic analysis of chalcedony-bearing high-grade veins reported from Hishikari, Japan, in which oxygen isotope results are indicative of extreme boiling and hydrogen isotopes indicate initial deposition of amorphous silica. The second is the finding of chalcedony within geothermal pipe work in the Rotokawa geothermal field in New Zealand. Rotokawa is a comparatively hot field (335¦C at depth); hence separation of the steam-water mixture produced by the wells is undertaken at a comparatively high temperature (220¦C) to minimise down-stream silica scaling. Even so, silica scale, some of which is chalcedony, does occur, under similar conditions to that in low-sulphidation epithermal deposits. Evidence of chalcedony forming under these conditions, reinforces the interpretation that decompressive boiling is the main deposition mechanism for gold in low-sulphidation epithermal deposits. It is possible that there is sufficient drop in temperature due to decompression that, at least initially, the silica deposits directly as chalcedony. Low-sulphidation epithermal gold deposits that do not contain chalcedony, such as those in the Philippines, may form at temperatures too high for chalcedony to directly form. The recognition of decompressive boiling as the main deposition mechanism in low-sulphidation epithermal deposits means that exploration can focus on zones where this has taken place by combining paleohydrological reconstruction and structural geology.

Jan 1, 2002

By Eugene McAuliffe

THE last obtainable figures of the value of the coal mining investment are those contained in the U. S. Census Reports, from data gathered in 1919. The values shown therein and set forth below cover lands and equipment and do not include distribution and marketing facilities. The working capital necessary to meet pay rolls to purchase material and supplies and workmen's compensation insurance are likewise excluded.

Jan 1, 1926

By Qingxiang Huang

Shallow seam coal field has the largest coal reserve in China. Mining in shallow depth causes serious problems. One of them is subsurface dewatering. In this paper, the physical simulating model was performed to study overburden movement and aquiclude stability in the shallow seam mining of Yushuwan coal field, China. According to the characteristic of clay aquiclude in the overburden, the proper simulation materials and proportions of mixture for simulating the plastic clay aquiclude layers and brittle bedrock layers were determined by the stress-strain tests. The physical simulating model was carried out to simulate the failure and caving process of the roof and overburden. Based on the simulating tests, it was found that the movement of clay aquiclude follows the movement of the underlying bedrock layers. The basic caving mechanism of the overburden roof strata was also presented. The tests also showed that the best way to control the stability of aquiclude is to reduce the subsiding gradient Ts. This research provides a foundation for further study on mining dewatering and water conservation.

Jan 1, 2006

By Aquiles Vivar

Ante los problemas de sismicidad inducidos por el sistema de minado en la Compañía minera Milpo, se planteó una solución a través del sistema de monitoreo sísmico único, donde se da una distribución espacial de 20 censores entre uniaxiales y triaxiales distribuidos en 3 niveles de producción en el área de influencia de las actuales operaciones para así ubicar, cualificar y cuantificar el fenómeno a efectos de realizar los análisis interpretativos del caso. En ese sentido, el presente texto describe el sistema de monitoreo, cuyo software sísmico está diseñado para determinar nuevas estructuras formadas a partir de los eventos sísmicos pre existentes reactivadas por la sismicidad inducida, así como el desarrollo de planos de isocontornos que permiten la diferenciación entre zonas de altos y bajos esfuerzos.

Sep 9, 2007

By L. K. Weaver

The Bureau of Mines has started an engineering study of oil recovery by miscible-phase displacement. As a preliminary part of the investigation a literature and patent study was made to prevent duplication of work already done, to become acquainted with those actively engaged in research of this type, and to learn where the recovery method has been attempted. This bibliography gives results of this study. The bibliography includes 254 references to U.S. and foreign patents and published literature relating to miscible-phase displacement processes of oil recovery. It is divided into the following sections: (1) U.S. patents, (2) foreign patents, (3) literature references, (4) author index, and (5) publication and source reference. The patents and literature references are listed alphabetically by author by intervals of years. References to February 1963 are included.

Jan 1, 1963

One of the chief drawbacks to Bendigo mining always has been the difficulty of draining the mines in an equitable manner, so that each company or mine owner bears the properly share. The trouble seems to have been apparent on this field since the diggings were discovered. One mine would push on more expeditiously than its neighbour in looking for the precious metal and sink its shaft, whilst those in the vicinity would simply potter about, and discontinue sinking until gold was struck in the deeper ground, and: then they would go ahead, start sinking, while the pioneer would have to pump all or most of their water. This sort of thing continued here for years until the leases were worked down to the very deep ground and the water became such a b.urden on those companies that had deep shafts, that first one stopped hauiing and then others; with the result that over 1000 feet of water was allowed to accumulate on the New Chum line. lt appeared that if something were not done the whole of the main line of reef in the Bendigo district would be at a standstill, when a scheme was formulated and handed to Mr. Lansell, who, with other gentlemen, took the matter up, and at the present time all the mines on that particular portion of reef are in full work and the water all bailed out.lt is this scheme that I am requested to place before you and also to give you the details of the work done since its adoption.

Jan 1, 1902

In New York City, on the walls of the library of the United Engineering Societies are these words:"Engineering-the art of organising and directing men and of controlling the forces and materials of nature for the benefit of the human race," but who, reading the schedules of even our best engineering schools, would infer that engineering is an art or that it should always havejn mind the benefit of the human race? While it must be remembered that our engineering schools exemplify the British cult of the amateur, that cult which lets men who have never attended a lecture on "Education" or perhaps nevereven read a book on it, become enginering teachers by profession (and so educators by inference), the root of the matter is to be found in the fact that our educational aims, and consequently our educational practice, seem suited much better to the position engineering held in the community in 1900 than to the position it holds to-day. This civilization of ours has developed, !;loth for good and for ill, into one based largely on engineering achievement; technical progress is so continuous and so rapid that thevalue of descriptive knowledge of current practice is ever lessening; enough must be imparted to make the young graduate immediately employable, and this amount is sufficient for illustrating the principles on which practice is based and on which its advance depends, but the young graduate's technical progress depends much less on his having acquired additional knowledge than on his ability to acquire knowledge, so, paradoxically, the more useful knowledge there is availabJe the less of it the student should be taught.Less conspicuous but fully as important is the enlargement of the field of work of engineering graduates, especially its extension to the initiating of policies and to the broader problems of administration. At present the road to such positions lies normally through a considerable period of professional work, but it is by no means unlikely that the field will soon include much that requires little professional expel'ience. At all events it is safe to say that the changed. and changing position of engineering in the communitydemands the attention of the engineering schools and that profitable discussion of engineering education demands some understanding of the real nature of education and of the part which engineering plays in the life of the community.THE NATURE OF EDUCATIONUnfortunately "to educate" supplies an example of how words degenerate in meaning; most people regard it as the equivalent of "to instruct"; a small number feel they have gone to. the root of the matter when they say...

Jan 1, 1941

By Gregory J. Canivan

Three test pile programs were conducted in Charleston, South Carolina to evaluate differences in bearing resistance due to installation methods. The tested piles were installed with impact hammers and vibratory drivers through soft clays and/or loose sands into the Cooper Marl, a stiff calcareous marine clay or silt. Piles driven into the Cooper Marl experience significant capacity gain with time following initial installation due largely to pore pressure dissipation. Pile size and pile type were both known to affect pore pressure generation during installation and subsequently the capacity gain with time. The test programs were primarily conducted to optimize pile design values and construction methods with regard to trestle construction but the results also contribute to the understanding of driven pile behavior. High strain dynamic testing was performed on several open-end pipe and H-piles. The measured difference in long-term bearing capacity of the H-piles as a result of the two installation methods was negligible, while the short-term bearing capacity of the pipe pile was larger when the piles were installed using impact hammers. The lower short-term resistance in the vibratory driven piles is attributed to larger excess pore pressures generated during installation compared to those generated during impact driving.

Jan 1, 2002

By Richard J. Mainiero, Michael J. Sapko, Marcia L. Harris

Since 1988, there have been thirteen documented incidents in the United States and Canada in which carbon monoxide (CO) is suspected to have migrated through near surface strata into structures or other enclosed spaces as a result of nearby trench blasting or surface mine blasting. From these incidents, there are thirty suspected or medically verified CO poisonings and one fatality associated with these incidents. To better understand the variables contributing to this hazard, the National Institute for Occupational Safety and Health (NIOSH) carried out a small- scale field study to identify key factors that may contribute to the migration of CO through the ground. NIOSH conducted single- hole heavily confined experimental test shots to measure the radial pressure pulse as it propagated through surrounding monitoring holes to determine if a relationship existed between the pressure pulse and resulting CO measurements afterwards. NIOSH also monitored blasts at an airport construction site. Following the detonations, the concentrations of CO, nitric oxide (NO), and nitrogen dioxide (NO2) were monitored for several days in the surrounding satellite holes. The peak CO measurements relative to distances from the shots were compared. Pressure histories and peak particle velocities (PPV) were measured at monitoring boreholes. It was found that the differential pressures recorded within the boreholes give some indication as to the likelihood of CO appearing, whereas the PPV measurements do not seem to be as good an indicator for potential CO migration. In this limited study, changes in barometric pressure had very little influence on removing the trapped detonation products, whereas applying a vacuum to the monitoring holes was effective in reducing the entrapped CO concentration.

Jan 1, 2005