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By Peter F. R. Altounyan, Paul B. Cartwright, John W. Cassie

This paper describes measured data on strata behavior obtained in recent years from sites in the United Kingdom and the implications for pillar design. The data include results from overcoring stress measurements adjacent to coal mine roadways and deformation monitoring related to longwall extraction. The stresses adjacent to mine roadways or entries have been measured at a number of coal mine sites in the United Kingdom. The results are analyzed with regard to the information they provide on pillar behavior and strength estimates. A reduction in stress consistent with yielding of the strata adjacent to the roadways is evident. This is consistent with the confined core model for pillar behavior. The pillar strength is dependent on the rate atwhich vertical stress can increase with distance from the pillar edge and hence the confinement provided to the yielded material. The measured data indicate a wide range in pillar strengths. Two groups of results are identified that show significantly different behavior corresponding to differing effective pillar strengths. Estimates of pillar strengths derived from the measured data for these two groups are compared with established equations used for pillar design. The differing behaviors and strengths are attributed to variations in the amount of yielding and deformation in roof and floor strata and hence in the amount of confinement they provide to the coal seam. Numerical modeling is used to provide a comparison with the measured data and to indicate that this provides a feasible mechanism to account for the measured data. As the depth of mining increases, pillars tend to become increasingly wide and squat. In such cases, it is possible for the surrounding roadways to become badly deformed and damaged while the pillars remain stable. The criteria of comparing pillar strengths and loads to establish pillar stability become less applicable in these circumstances; rather, considerations of roadway stability may be the limiting factor in determining suitable pillar dimensions. This is the case for pillar dimensions typically employed around longwall panels in the United Kingdom. Depending on the properties of the site and what are deemed to be satisfactory roadway conditions, this can lead to wide variations in required pillar dimensions. Measured data for deformations in roadways influenced by adjoining longwall workings are presented. These show that in some circumstances the influence of longwall extraction can be transmitted over large distances and confirm the variability in required pillar sizes depending on site properties.

Jan 5, 1999

SMCRA contains five principal regulatory provisions that form the basis for its implementation: Performance Standards Performance standard safe intended to ensure that all surface mining is conducted in a way that protects the environment and the public and ensures that the mined land is restored to productive use following mining. Permits Before developing a surface or underground coal mine, an operator must have a permit issued under SMCRA. An application for a permit to conduct a surface coal mining operation is a detailed document that consists of text and numeric data describing the proposed mining and reclamation. Information must be furnished on pre-mining environmental conditions, existing land use, proposed mining and reclamation, how the performance standards will be met, and the post-mining land use. This provides the regulatory authority with the information necessary to determine that the operation can be conducted in accordance with the regulations. Performance Bonds Before a permit can be granted, an operator must post a performance bond sufficient to cover the cost of reclaiming the site in the event the operator fails to complete reclamation. The bond is not fully released until all performance standards have been met and reclamation of the site has been determined to be successful after five years in the East and Midwest, and after 10 years in the arid West. However, the bond can be partially released as various phases of reclamation are completed. Inspection and Enforcement If a violation of SMCRA or of a state surface mining and reclamation law is observed, an inspector issues a notice of violation to the operator. The violation must be corrected within a specific time, and the operator may also have to pay a fine based on the severity of the violation. If the violation is not corrected, acessation order is issued to immediately stop active coal mining, and the operator must pay a fine. If a violation is especially serious (for example, creates an Following reclamation, the land was immediately put back into agricultural production. Today, grain and corn crop yields have continually exceeded targets. 2 imminent danger to public health or safety or causes significant damage to land, air, or water resources) the inspector immediately issues a cessation order. An operator must correct all violations in order to obtain permits for new mines. Lands Unsuitable For Mining Congress recognized that certain coal deposits cannot be mined without permanent damage to unique cultural or natural resources. As a result, SMCRA protects these resources in two ways: It prohibits mining within the boundaries of national parks, forests, wildlife refuges, trails, wild and scenic rivers, wilderness and recreation areas; in areas which will adversely affect sites listed on the National Register of Historic Places; and within a restricted distance of occupied dwellings, public roads, buildings, parks, schools, churches, and cemeteries; and Provides a process that allows anyone whose interests may be adversely affected by proposed mining to petition to have specific lands designated unsuitable for mining.

Jan 1, 1992

The Mine Safety and Health Administration (MSHA) defines an independent contractor as "any person, partnership, corporation, subsidiary of a corporation, firm, association or other organization that contracts to perform services or construction at a mine." Contractors that perform specific types of work are required to report the number of employees who perform work at coal mines and at noncoal mines.

Jan 1, 2004

By BUREAU OF MINES

The Bureau of Mines in its investigations of respiratory apparatus for use in mines and allied industries, tests equipment that is voluntarily submitted by manufacturers in accordance with published schedules of tests. These tests are designed to insure that the equipment has the minimum require- ments for safety in use. Approval certificates are issued for apparatus that meets the bureau's specifications, and the memfacturer is permitted to mark his equipment with a seal showing that it has been approved as "Permissible." A complete list of permissible self-contained oxygen breathing apparatus, gas masks, and hose masks tested before July 1, 1930, was published in Bureau of Mines Information Circular 6362.1 The present list includes all equipment tested and approved up to and including April 1, 1931.

Sep 1, 1931

By M. B. Cooke

In the course of investigation now in progress by the Bureau of Mines into the nature of " gum forming" constituents of gasoline , several gasolines and other petroleum products were heated in a small bomb , and pressures of considerable magnitude were developed . As the Bureau has received many inquiries for data showing the pressure that may be developed in a still when gasoline or other oil is subjected to elevated temperatures , it was thought advisable to record the pressures observed at various temperatures in the course of this work . data were merely a by- product of the main investigation . These Gasoline and similar products are very complex mixtures , and it is difficult to determine accurately the true vapor pressures , hence the vapor pressures of the oils used in these tests have not been studied in detail , but the data obtained may be taken as representative of the pressure- temperature relations of the various oils in commercial work.

Jun 1, 1922

By D. Harrington

Examination of numberous disasters , such as fires or explosions , and the evidence at coroner's inquests following such disasters in several States , have shown the writer how frequently men in charge of the operation and safety of mines have forgotten, or have failed to learn , details of safe mining practices , After securing a position of trust as superintendent , or a certificate of competency to act as shot -firer , fire boss , or mine foreman, some men seem to have felt it unnecessary to keep safety principles in mind , or to keep abreast of current progress in safety ; they have concentrated on getting out maximum tonnage at minimum cost . • In coroner's inquests , the testimony after disasters has shown that firebosses , foreman , and coal -mine superintendents are noticeably lacking in knowledge of the provisions of the State mining law relating to fans or doors , frequency of crosscuts , nature of stoppings necessary , electrical equipment , records of daily mine examinations , quantity of air required , or splitting and overcasting .

Jul 1, 1922

By W. C. Phalen

"The term ""manjak"" is applied to a variety of bitumen or solid hydrocarbon occuring on the Island of Barbados, West Indies, and in Utah, Cuba, and Trinidad. The deposits on the latter island are found within a distance of three miles of San Fernando, the second largest town on the Island, and within three miles of the famous asphalt lake.In chemical composition, manjak is like asphalt. It is almost pure bitumen. Its melting point is, however, more than 4000F. whereas asphalt melts at 1000F. In composition, it consists of 80 to 90 per cent carbon, the balance being chief¬ly hydrogen, with a small quantity of sulfur. It resembles coal in appearance, is odorless, hard, and brittle. It is found in thin beds between layers of clay.The island of Trinidad is rich in this mineral resource. Its development has as yet hardly begun, and the exportations already made have been with the view of testing out the ma-terial. During 1918, exports to the United States were valued at about $3100, and in 1919, up to October 1, they totaled 41 tons, valued at $1900. Prior to 1900, manjak was mined on a small scale in Trinidad, but for various reasons, very little was done between 1900 and 1913. In the latter year, mining operations were resumed by the Trinidad-Tarouba Oil Development Company, of San Fernando. At the present time, there are five shafts, one of which has reached a 37 foot bed of manjak at a depth of 400 feet. Operations could be greatly extended if there were a greater demand for the material.It has not been found profitable to export manjak from Trinidad in the crude state as the price received, namely $35 per ton, hardly covers mining expenses. These are increased by the necessity for careful and thoro timbering on account of the clay formation.Compounds, made by combining manjak with mineral oil command fair local prices which have enabled mine operations to proceed at a profit. Experimentation is still in progress with different mixtures of manjak and oil for various purposes. The manjak, recently sent to the United States was for the purpose of ascertaining whether American oils would be more economical and useful for mixing with the manjak than the Trini¬dad oils. It is the plan to erect a plant very soon for the manufacture of a variety of manjak paints and compounds.Manjak is rapidly increasing in use, particularly in connection with the oil industry. It is produced in close proximity to the oil wells in Trinidad. It is boiled with oils at high temperatures and converted into compounds and paints for nearly every purpose where a preservative is needed, for example, on pipe lines, boilers, chimneys, and miscellaneous iron ware, machinery, etc. It is usually applied in the liquid state, hardening into a tough, rubberlike coating. It has low viscosity, and is not affected by ordinary heat. It makes an excellent insulating material and is impervious to both air and water. In hot and damp climates, like that of Trinidad where pipe lines quickly deteriorate, their life has been pro-longed for extended periods when painted with this material."

Nov 1, 1919

By Elaine T. Cullen

Safety training materials appropriate for specific underground noncoal operations in the United States are often outdated or nonexistent. The Spokane Research Laboratory (SRL) of the National Institute for Occupational Safety and H ealth has developed several new training tools, including three videos on common underground activities, software that will allow trainers to create a virtual training mine using their own mine map, and toolbox training materials. SRL is working closely with industry in the development of these tools. Teams of safety professionals are involved in the early stages, and actual mines and miners are involved throughout the production phase. This presentation describes the development process and results of SRL’s safety training projects.

By RUDULF KUDLICH

Pennsylvania anthracite coal is almost universally recognized to be the solid fuel best suited for domestic use when cleanliness , convenience and cost are considered . At various times and in various localities , however, conditions so affect the supply that it becomes insufficient or is too high in price and recourse must be had to other fuels as substitutes . In practically every district in the United States where anthracite has been the common domestic fuel , some other fuel is available as a substitute . In even the most severe climates such fuels are used either as emergency substitutes for anthracite , or as the ordinary domestic fuel . There may be some drawback to the use of such fuel , such as the need of more frequent attention to the furnace , smoke , soot and dust , in the case of solid fuels lower in price than anthracite , but these inconveniences must be accepted as necessary accompaniments to a decreased fuel bill . The cleanliness and ease of handling anthracite in the house must be considered in the light of a luxury and a higher cost of heating with this fuel must be expected . That a growing number of people are willing to pay for such added convenience is evident from the increasing mumber of heating installations using oil , gas and electricity , all of which are more convenient and usually more expensive even than anthracite .

Aug 1, 1923

Jul 1, 2003

To develop a comprehensive, practical method for designing longwall gate entries that considers coal pillar size, mine roof quality, and artificial support in an easy-to-use computer program.

Jan 1, 1995

By M. Brnich, L. Mallett, C. Vaught, K. Kowalski

This paper discusses the data collected during an emergency evacuation training exercise at an underground mine in the United States. The focus of this paper is on the human reaction to smoke and the use of personal protective equipment. Specific issues related to the human stress response during an emergency will be discussed.

By R. V. Ramani, R. Stefanko, G. W. Luxbacher

THIS PROGRAM TRANSFORMS FREE FORHATED BRANCH DATA INTO A FORMAT SUITABLE FOR INPUT TO THE PENNSYLVANIA STATE UNIVERSITY MINE VENTILATION SIMULATOR (PSU/HVS 1. BRANCH RESISTANCES ARE ASSUMED TO HAVE BEEN ALREADY CALCULATED, IIOWEVER THIS PROGRAM CAN BE EASILY MODIFIED TO HANDLE THE ADDITIONAL INPUT DATA REQUIRED FOR RESISTANCE CALCULATIONS IN THE PSU/MVSO THE PROGRAM IS WRITTEN IN FORTRAN IV WITH WATFIV.

Jan 1, 1977

By Edward McHugh, Jami M. Girard, Stanley M. Miller

A computer analysis of bench stability has been developed to account for multiple occurrences of potential slope-failure modes in discontinuous rock masses. Bench-scale plane shears and tetrahedral wedges are simulated and stochastically analyzed to estimate the probability of retaining specified catch-bench widths. This geotechnical information is useful in designing bench configurations to improve pit-slope stability and help alleviate rockfall hazards.

The NIOSH Office of Mine Safety and Health has released communication products about flyrock safety in the form of informational brochures, flashcards, and toolbox talk materials. Both the mining and construction industries are targeted with these helpful communication tools. These new products can be used as refresher training for employees and as introductory safety materials for onsite visitors.

Dec 1, 2006

By Rudolf E. Greuer, Linneas W. Laage, Xinton Chang

The program MFIRE consists of four files MFIRE0 EXE, MFIRE1 EXE, MFIRE2 EXE, and MFIRE BAT The batch file, MFIRE BAT, controls the operation and cooperation of the three executable pro¬gram files and the output Networks of up to 500 air¬ways and 350 junctions can be modeled in the PC version of MFIRE Larger data sets can be accommodated by increasing array dimensions and compiling the program again. Input for MFIRE is in the form of a data file The data file contains fines of numerical data describing the physical mine, the ventilation parameters present, the fans, and the proposed thermal or mechanical disturbances

Jan 1, 1990

To develop a safety training module for surface miners and road construction workers exposed to the hazards of highwalls. Background Investigators collaborated to develop a new training module that would address the hazards of working around highwalls. Such a module would be applicable to surface mines and road construction sites, both of which require personnel to work under and on top of steep and often unstable slopes.

Aug 1, 2004

Table XXXIII itemizes the cost associated with the installation of an irrigation system and the application of latex and water in the three experimental areas at Lanse. There were no external labor charges (non- Research Center) except for the installation of the water meter. Cost of pipe and fitting are high because long lines were required at each of the three different locations; these costs were minimized by using plastic instead of metal pipe. Fifteen of the seventeen drums of latex received were used, five drums for each area. [ ] In tank-car lots latex would cost about $0.25/lb so that raw material cost for a 4000 lb/acre application would be in the range of $1,000 per acre. Equipment costs for setting up and irrigation are sensitive to size of area to be irrigated, design of system, and availability and cost of water. A realistic range is estimated to be between $200-500/acre.

Jan 1, 1972

By Robert F. Randolph

Research on improving haulage truck safety, started by the U.S. Bureau of Mines, is being continued by its successors. This paper reports the orientation of the renewed research efforts, beginning with an update on accident data analysis, the role of multiple causes in these accidents, and the search for practical methods for addressing the most important causes. Fatal haulage accidents most often involve loss of control or collisions caused by a variety of factors. Lost-time injuries most often involve sprains or strains to the back or multiple body areas, which can often be attributed to rough roads and the shocks of loading and unloading. Research to reduce these accidents includes improved warning systems, shock isolation for drivers, encouraging seatbelt usage, and general improvements to system and task design.

Jan 1, 2000

By Brian G. White, Theodore J. Williams, Jeffrey K. Whyatt

Detailed mapping and examination of the site of a large rock burst at the Lucky Friday Mine, Mullan, ID, demonstrated conclusively that damage was caused by a splitting and buckling failure mechanism initiated by separation of rock into layers along steeply dipping metamorphic shear foliation subparallel to the affected crosscut. The thin tablular layers then buckled into the crosscut from both sides. Rigorous control of the burst by these layers suggests practical measures for avoiding bursts in crosscuts in the future by repositioning and reorienting openings so that splitting and buckling are reduced or precluded.