Overviews

Analysis of Highwall Mining Stability - The Effect of Multiple Seams and Prior Auger Mining on Design (PDF, 1182 KB, 2005)
The objective of this is paper is to review the current state of knowledge and practice in highwall mining.

Empirical Design of Span Openings in Weak Rock based upon Support Type Employed (PDF, 115 KB, 2008)
This paper presents a focus of ground control research presently being conducted by the Rock Mechanics Group in the DBC Mining Department in incorporating weak rock masses (RMR₇₆ <50) into existing empirical design relationships. This work attempts to provide rock mechanic tools that will enable a mine operator to make economic decisions that will also ensure a safe working environment.

Ground Control for Highwall Mining (PDF, 508 KB, 2007-09)
This paper discusses the two most significant highwall ground control hazards; rock falls from the highwall and equipment entrapment underground.

Work Practices to Manage Bump Prone Ground (PDF, 204 KB, 2008)
This paper will review current and historic work practices used internationally to minimize the hazard to miners from mining in conditions which could produce a bump.

Software

ARMPS-HWM - Analysis of Retreat Mining Pillar Stability - Highwall Mining
ARMPS-HWM is a modification of Analysis of Retreat Mining Pillar Stability (ARMPS) software for designing web and barrier pillars for Highwall Mining (HWM).

AMSS - Analysis of Multiple Seam Stability
Multiple seam interactions are a major ground control hazard in many US underground coal mines. The two most common types of interactions are: Undermining, where stress concentrations caused by previous full extraction in an overlying seam is the primary concern, and; Overmining, where previous full extraction in an underlying seam can result in stress concentrations and rock damage from subsidence. AMSS helps identify the location and likely severity of these interactions. Mine planners can use this information to adjust the roof support, pillar design, or mine layout to minimize the hazard.

LAMODEL - Stress and Displacement Calculations
LAMODEL is software that uses boundary-elements for calculating the stresses and displacements in coal mines or other thin, tabular seams or veins. It can be used to investigate and optimize pillar sizes and layout in relation to pillar stress, multiseam stress, or bump potential (energy release).

STOP - Support Technology Optimization Program
STOP is a software tool that provides mine operators with a simple and practical tool to make engineering decisions regarding the selection and placement strategy of these various standing roof support technologies. This program includes a complete data base of the support characteristics and loading profiles obtained through safety performance testing of these supports at the NIOSH Safety Structures Testing Laboratory.

AHSM - Analysis of Horizontal Stress Effects in Mining
AHSEM contains two modules to improve mine layouts for control of horizontal stress. For development, the user specifies the orientations of the entries, the crosscuts, and the maximum horizontal stress.

ALPS - Analysis of Longwall Pillar Stability
ALPS is a computer program for use in the design of pillars for longwall mines.

ARBS - Analysis of Roof Bolt Systems
ARBS is a software toll for selecting roof bolts for primary support in underground coal mines.

ARMPS - Analysis of Retreat Mining Pillar Stability
ARMPS is a software tool for designing pillars for room-and-pillar retreat mining.

CMRR - Coal Mine Roof Rating
The Coal Mine Roof Rating is a roof classification system that was first introduced to the mining community in 1994. The CMRR is a rock mass classification system which calculates the inherent strength of coal mine roof. It can be used in the design of gateroads, roof bolt selection, extended-cut decisions, and numerical modeling.

Guides

Guidelines for Permitting, Construction, and Monitoring of Retention Bulkheads in Underground Coal Mines (PDF, 508 KB, 2008-06)
The guidelines in this report are to be used as a tool to identify areas or conditions that could impact the long-term stability of an underground fluid retention system and to give direction in addressing these situations.

Shear Origin of Tension in Excavation-Induced Fractures (PDF, 396 KB, 2003)
The authors hypothesize that excavation-induced extension fractures are caused by elastic shearing displacement that in turn causes tension oblique to a propagating shear zone.

A User's Guide for the Bplane, Bstepp, and Bwedge Computer Programs (PDF, 2108 KB, 2007-03)
This user's guide covers the operation of a suite of three computer programs - Bplane, Bstepp, and Bwedge. These programs can be used to evaluate the potential for plane shear, step-path, and wedge failures along the crest of a slope bench. The theoretical basis, application, and operation of these programs are described.

TGRSS - Troubleshooting Guide for Roof Support Systems
This guide provides a logical sequence to resolving the most common problems encountered with roof supports.

Measurement & analysis

Analysis of Multiple Seam Stability (PDF, 658 KB, 2007)
NIOSH completed a major study to identify the location and likely severity of multiple seam interactions (undermining and overmining). More than 300 multiple seam case histories were assembled into the largest data base of multiple seam case histories ever collected. These data were analyzed with the multivariate statistical technique of logistic regression, LaM2D to estimate the multiple seam stresses, ALPS and ARMPS to determine pillar stability factors, and the CMRR to measure roof quality. The study resulted in the development of a computer program, called Analysis of Multiple Seam Stability (AMSS), which can help mine planners to evaluate each potential interaction and take steps to reduce the risk of ground control failure.

Coal Mine Bumps: Five Case Studies in the Eastern United States (PDF, 3464 KB, 1987)
Information was collected on the geologic conditions, mining techniques, and engineering parameters at five bump-prone mines. Two geologic conditions have been found to cause the occurrence of bumps in the eastern United States: (1) relatively thick overburden and (2) extremely rigid strata occurring immediately above and below the mine coalbed. Additionally, the probability of bump occurrence is increased by certain mining practices that concentrate stresses during retreat mining in areas where geologic conditions are conducive to bumps. Mining plans that permit the development of pillar line points or long roof spans that project over gob areas should be avoided because these features may contribute to the occurrence of bumps.

Correlation of Sonic Travel Time to the Uniaxial Compressive Strength of U.S. Coal Measure Rocks (PDF, 591 KB, 2008)
This paper describes research conducted by NIOSH aimed at developing a correlation between sonic travel time logging of exploration boreholes and estimates of coal mine roof rock strength.

Development of New Protocols to Evaluate the Transverse Loading of Mine Ventilation Stoppings (PDF, 338 KB, 2006-06)
A new protocol based on rigid arch loading of the structure is proposed to determine the true transverse load capacity of block stoppings. The rigid arch tests have shown that the load capability is dependent on the physical properties of the block and geometric properties of the wall, not the sealant.

Dyanmic Failure in Deep Coal: Recent Trends and a Path Forward (PDF, 301 KB, 2008)
The centerpiece of this project is development of a Dynamic Failure Control Program to monitor evolution of dynamic failure hazards with changing geologic conditions to assure that control and protective measures are appropriately deployed.

The Effect of Standing Support Stiffness on Primary and Secondary Bolting Systems (PDF, 248 KB, 2003-08)
Standing crib supports have been applied in underground mining programs to resist large roof movements and sustain high-loads. The parameter that has not been examined and is not well understood is the effect that a crib or other types of standing support has on the primary and secondary bolting systems. Utilizing a combination of field measurements and 3-dimensional finite element modeling techniques, the relationship between system stiffness and the subsequent performance of the installed bolting system is evaluated.

Effect of the Dip and Excavation Orientation on Roof Stability in Moderately Dipping Stone Mine Workings (PDF, 1007 KB, 2005)
Underground limestone mines typically use the room-and-pillar method of mining in the generally flat-lying limestone formations. In some cases the dip may exceed 5° which can result in unique roof instability problems. Stability may be further exacerbated by the presence of horizontal tectonic stresses. Field studies and numerical model analyses are combined to assess the effect of the dip in various stress conditions.

Effects of Specimen Age on the Uniaxial Compressive Strength of Weak Coal Measure Rocks (PDF, 764 KB, 2008)
This paper presents the results of a NIOSH study to evaluate UCS changes occurring in a broad range of weak coal measure rocks over a one-year time span.

Evaluation of Pillar Recovery in Southern West Virginia (PDF, 636 KB, 2002-08)
Studies conducted have identified a number of "risk factors" that can be used to evaluate pillar extraction plans: cut sequence; final stump; timber or mobile roof supports; roof bolting; intersection span; depth of cover; roof quality; and age or workings. This paper discusses each of the risk factors in turn, presents the relevant accident statistics, and shows how the risk factors can be combined to estimate the overall hazard.

Evaluation of the Transverse Load Capacity of Block Stoppings for Mine Ventilation Control (PDF, 7182 KB, 2005)
A new protocol based on arching has been developed to determine the true transverse load capacity of stoppings.

An Examination of the Loyalhanna Limestone's Structural Features and their Impact on Mining and Ground Control Practices (PDF, 2678 KB, 2002)
A close look at the Loyalhanna Limestone of southwestern Pennsylvania reveals a complex structural environment.  Geologic and engineering analyses were performed using gas well and core logs, outcrop examinations, underground observations, and mine maps. Many of the structural conditions cause ground control problems at local quarries.

Field-Scale Void Detection in Coal Piles Using Resistivity Imaging (PDF, 822 KB, 2002-07)
This paper summarizes the results obtained from a field-scale test and shows that mapping voids within a coal pile is possible.

Global Trends in Coal Mine Horizontal Stress Measurements (PDF, 452 KB, 2008)
This paper explores the relationships between deep-seated and shallow in situ stresses in several of the world´s coalfields, using a data base of more than 350 stress measurements from underground coal mines.

Identifying Moisture Sensitive Roof Rocks in Coal Mines (PDF, 850 KB, 2006)
NIOSH conducted wet/dry immersion cycling of clay-rich rocks. The wet/dry immersion cycling test used provides an accurate, quick and inexpensive method for estimating the moisture sensitivity of mudrocks. With this information mine operators can begin to anticipate hazardous ground and prepare appropriate roof support.

Improving the Capability for Real Time Assessment of Roof Conditions Through Intelligent Roof Bolt Drilling Operations (PDF, 714 KB, 2007)
This paper describes an intelligent drilling system that can complement scoping and core analysis to provide a more complete picture of roof strata and is capable of seeing features or conditions that are not always obvious in more traditional methods.

In Situ Stress Measurements at the Stillwater Mine, Nye, Montana (PDF, 457 KB, 2003)
Using hollow inclusion stress cells, researchers obtained two in situ stress measurements from the face of two footwall lateral drifts at the Stillwater Mine near Nye, MT.

Initial Stability Study of Large Openings for the National Underground Science Laboratory at the Homestake Mine, Lead, SD (PDF, 206 KB, 2002-07)
The investigation reported here is an initial study of the stability of the first of the proposed chambers at the Homestake Mine in Lead, SD.

Longwall Retreat of Gate Road Pillars (PDF, 1244 KB, 1993-01)
This report describes an investigation into the removal of gate road chain pillars in conjunction with longwall retreat mining. The objective was to determine, through evaluation of the loads imposed on the gate road pillars and supplemental support elements in the entries, how the pillars, supplemental support, and entries were affected by the longwall abutment pressure. The findings are the result of information collected from instrumentation and observation at the mine.

Multiple Seam Mining Interactions: Case Histories from the Harris No. 1 Mine (PDF, 3415 KB, 2005)
The most significant findings of this investigation was that the size of the remnant upper seam structure can influence the extent of the multiple seam interaction. More specifically, this study suggests that smaller critically loaded upper seam pillars are more likely to cause lower seam ground control problems than are wider pillars. The LaModel program was used to examine this supposition and the results verified this premise.

Multiple-Seam Mining in the United States: Background (PDF, 8193 KB, 2007-05)
In some U.S. coalfields, particularly in central Appalachia and the West, the majority of today's mines are operating above and/or beneath previously mined seams. The effects of multiple-seam interactions can include roof falls, rib spalling, and floor heave, which can seriously disrupt mining operations and threaten the safety of miners. Accurate prediction of which interactions are likely to be higher-risk allows mine planners to prepare for them or avoid them. For the past several years, NIOSH has been conducting research to develop better techniques for predicting the location and severity of multiple-seam interactions. This paper presents the background to that study.

Multiple-Seam Mining in the United States: Design Based on Case Histories (PDF, 9281 KB, 2007-05)
Multiple-seam interactions are a major ground control hazard in many U.S. underground coal mines. The two most common types are: Undermining and Overmining. The goal of the study described in this paper is to help identify the location and likely severity of these interactions. Mine planners can use this information to adjust the ground support, pillar design, or mine layout to minimize the hazard. NIOSH relied mainly on an empirical approach. Empirical methods in ground control start with the concept that real-world mining experience, in the form of case histories, can provide valuable insight into the performance of very complex rock mechanics systems.

Numerical Modeling of the U1A Complex at the Nevada Test Site: Model Development and Comparison of Different Drift Mining Options (PDF, 810 KB, 2003-08)
A three-step method is presented to determine nonlinear stress-strain curves for boundary-element programs used in many mining applications. The method requires a suite of laboratory-scale strength tests at various confining pressures.

Numerical Modeling Procedures for Practical Coal Mine Design (PDF, 457 KB, 2006-06)
A method is presented for creating realistic numerical models for practical coal mine ground control. The method includes procedures to collect the necessary mechanical input parameters from a geologic core log, to set up a model, and to interpret calculation results. This procedure enables realistic comparison of the effectiveness of alternative rock support systems.

Observations and Evaluation of Floor Benching Effects on Pillar Stability in U.S. Limestone Mines (PDF, 204 KB, 2007)
A survey of roof and pillar conditions in underground limestone mines in the United States has revealed that bench mining of the floor between pillars can cause instability in the pillars at the perimeter of the benched area. The paper describes a study that was carried out using numerical models to assess the effects of bench mining on pillar load and stability.

Performance of a Polyurethane Core Seal Tested in a Hydrostatic Chamber (PDF, 2963 KB, 2008)
This paper presents the results of the full-scale test of a composite polyurethane-aggregate seal in a hydrostatic chamber conducted by NIOSH Pittsburgh Research Laboratory at the Lake Lynn Experimental Mine, and provides an analysis of those results in terms of the structural behavior of the seal.

Proceedings: Mechanics and Mitigation of Violent Failure in Coal and Hard-Rock Mines (PDF, 24298 KB, 1995-05)
Papers presented at a U.S. Bureau of Mines technology transfer seminar describe the causes of violent material failure in U.S. mines, measurement techniques for monitoring events that result in violent failure, and mitigation techniques for controlling failure. Among the topics included are specific factors contributing to violent failure, new monitoring and analysis techniques, geotomographic methods that provide new capabilities for the study of material failure and stress changes over large areas, and seismic methods for determining source locations, calculating energy release, and determining source mechanisms.

Proceedings: New Technology for Ground Control in Multiple-seam Mining (PDF, 9281 KB, 2007-05)
Multiple-seam interactions are a major ground control hazard in many U.S. underground coal mines. In some U.S. coalfields, particularly in central Appalachia and the West, the majority of today's mines are operating above and/or beneath previously mined seams. For the past several years, the National Institute for Occupational Safety and Health has been conducting research to develop better techniques for predicting the location and severity of multiple-seam interactions. These Proceedings also contain previously published papers that cover facets of multiple-seam mining research as well as three papers that describe the extensive multiple-seam experience of the Harris Mine, examples of extreme multiple-seam mining from the central Appalachian coalfields, and longwall mine experiences in Pennsylvania, West Virginia, and Utah. The final paper reports on a numerical modeling study that provided some insight into the mechanics of multiple-seam mining.

Recent National Institute for Occupational Safety and Health Research Using Ground Penetrating Radar for Detection of Mine Voids (PDF, 1691 KB, 2003)
This study tested whether ground penetrating radar (GPR) could be used to resolve adjacent mine workings. Results indicate that it may be possible to utilize GPR for initial underground mine studies followed by directional drilling to accurately delineate the extent and position of adjacent abandoned mine workings.

Rock Mass Behavior and Support Response in a Longwall Panel Pre-Driven Recovery Room (PDF, 903 KB, 2008)
Some surprising results were revealed in this study designed and implemented by NIOSH to evaluate the effectiveness of pre-driven longwall recovery rooms supported with pumpable concrete roof supports.

Roof and Rib Hazard Assessment for Underground Stone Mines (PDF, 410 KB, 1998)
Roof and rib conditions were observed and assessed in 33 underground stone mines. Hazard assessment indicated that the ground failures that occurred under moderate to substantial overburden were caused by stress concentrations and geologic structures. Selection of the mining horizon and mine-layout decisions tremendously influence ground stability.

Stress Measurements for Safety Decisions in Longwall Coal (PDF, 1943 KB, 2002)
The goal of the research described here is to develop a stress monitoring system that will provide immediate information to mine managers for making daily safety decisions as areas of poor ground are mined through.

Three-Dimensional Time-Lapse Velocity Tomography of an Underground Longwall Panel (PDF, 2086 KB, 2008-06)
This paper describes the three-dimensional velocity tomograms that were generated to image the stress redistribution around an underground coal longwall panel to produce a better understanding of the mechanisms that lead to ground failure, especially rockbursts.

Using Site Case Histories of Multiple Seam Coal Mining to Advance Mine Design (PDF, 546 KB, 2003)
NIOSH is conducting research to develop mine design algorithms that will result in safer multiple seam mines. This paper presents an overview of multiple seam issues in the central Appalachian coalfields.

Case studies

Catastrophic Failures of Underground Evaporite Mines (PDF, 772 KB, 2008)
This paper examines catastrophic failures of evaporite mines (including salt, potash and trona) that show that violent failure does, in fact, occur and attempts to identify common factors and characterize the mechanism of failure.

Coal Mine Subsidence Prediction Using a Boundary-Element Program (PDF, 448 KB, 1999)
This paper presents several case studies in which a mechanics-based boundary-element program is used to back-calculate the surface subsidence associated with various panels at several northern Appalachian coal mines.

Extreme Multiple Seam Mining in the Central Appalachian Coalfields (PDF, 629 KB, 2006)
NIOSH is conducting research aimed at helping mine planners prevent hazardous conditions due to multiple-seam interactions. More than 300 case histories have been collected from underground mines mainly in central Appalachia. This paper focuses on several of the more challenging situations that have been encountered, including: room-and-pillar development 20 ft beneath full-extraction workings at a depth of 1,000 ft of cover; pillar recovery 45 ft above full-extraction workings at 900 ft of cover; near-simultaneous room-and-pillar mining with pillar recovery with 40 ft of interburden and 1,500-2,000 ft of cover; and longwall mining directly beneath main entries in overlying seams.

Investigation of Pillar-Roof Contact Failure in Northern Appalachian Stone Mine Workings (PDF, 366 KB, 2004-08)
The roof in underground limestone mines in Northern Appalachia can be subject to high horizontal stresses in spite of the shallow depth of the workings. A case study is presented in which failure at the pillar-roof contact was observed where the dip of the workings was 7 deg. in a high horizontal stress field. The high horizontal stresses at this site are an important contributing factor to the observed failures.

Underhand Cut and Fill Mining as Practiced in Three Deep Hard Rock Mines in the United States (PDF, 420 KB, 2007)
Details of the operational aspects of the backfilling and mining cycles at each of three mines in the western US are presented in this paper, accompanied by a summary of the mechanical properties of the backfill and its in-situ geomechanical behavior.

Engineering controls

60 Years of Rockbursting in the Coeur D'Alene District of Northern Idaho, USA: Lessons Learned and Remaining Issues (PDF, 409 KB, 2002-02)
Sixty years of rockbursting in the Coeur d'Alene district has taught painful lessons and led to a number of practical advances in controlling rockburst hazards. This paper summarizes those lessons, concentrating on practical measures that have been successfully adopted to reduce hazards.

Analysis and Design of Rib Support (ADRS): A Rib Support Design Methodology for Australian Collieries (PDF, 286 KB, 2005)
This paper summarises the results of a research project whose goal was to provide the Australian coal industry with a rib support design methodology and software tool that could be utilised by suitably qualified colliery staff.

Application of Ground Penetrating Radar to Evaluate the Extent of Polyurethane Grout Infiltration for Mine Roof Control: A Case Study (PDF, 1051 KB, 2004-08)
The objective of this study was to test the capability of ground penetrating radar to determine the extent of grout penetration into the mine roof strata in the 13-G room area of the NIOSH Safety Research Coal Mine. The study showed that GPR technology can be a useful tool for detecting changes in mine roof due to the injection of the grout.

Application of Parametric Column Analysis to Evaluate Eccentric Loading Conditions on Prop Support Performance (PDF, 304 KB, 2007)
This paper examines the effect of end conditions and load profiles on prop support performance and applies a new analysis methodology based on eccentric loading to determine a factor of safety for load capacity. Recommendations for installation practices that minimize eccentricity and therefore preserve capacity are also provided.

Characteristics of Mining-Induced Seismicity Associated with Roof Falls and Roof Caving Events (PDF, 312 KB, 2005)
This study used microseismic emissions to help identify three local rock failure processes. It was also shown that analysis of microseismic emissions can aid in assessing the degree of instability associated with these local rock failure processes.

Damage Delineation in Structures Using Laser Vibrometry and Remote Excitation (PDF, 447 KB, 2004)
As part of a research program to reduce injuries and fatalities in the U.S. mining workforce, NIOSH is investigating the potential use of noncontact vibration measurements to identify hazardous ground fall conditions.

Deep Cover Pillar Extraction in the U.S. Coalfields (PDF, 655 KB, 2002)
A study is described with the objective of evaluating the various methods and strategies by which panels, production pillars and barrier pillars are developed and extracted under deep cover, and to develop appropriate design guidelines.

Design Considerations for the Next Generation of Longwall Shields (PDF, 877 KB, 2001)
The purpose of this paper is to set goals for the future generations of longwall shields.

Determination of Physical Properties of Cable Bolts in Cement Grout Pull Tests Using Instrumented King Wires (PDF, 621 KB, 2000-04)
Researchers are investigating the physical properties of cable bolts by replacing the conventional king wire with a modified king wire on which strain gauges have been installed.

Development of Ground Response Curves for Longwall Tailgate Support Design (PDF, 587 KB, 2006-06)
This paper presents the results of a study into the ground response around tailgate entries using numerical models. The ground response is shown to be significantly affected by the strength of the immediate roof as well as the main roof. The importance of yield capacity of standing support is demonstrated. Gob height and compaction are found to affect the amount of convergence in the tailgate. The potential exists to develop site-specific tailgate design curves by combining model results with field observations.

Development of Numerical Models to Investigate Permeability Changes and Gas Emission around Longwall Mining Panel (PDF, 393 KB, 2005)
This paper describes the application of a finite difference program to develop a geomechanical model that predicts permeability changes within the rock mass.

Effects of Far-Field Shearing Deformation on Fracturing Around an Underground Opening (PDF, 1531 KB, 2004)
Researchers are investigating the causes and mechanisms of roof failure in underground mines. It is expected that a better understanding of these causes and mechanisms will lead to better layout and support designs that will help prevent accidents and fatalities associated with fall of ground.

Evaluation of the Impact of Standing Support on Ground Behavior in Longwall Tailgates (PDF, 255 KB, 2005)
The conclusion drawn from this study was that standing supports do not have sufficient capacity to control main roof or floor loading or prevent the resulting convergence of the tailgate entry.

Failure Mechanics of Multiple Seam Mining Interactions (PDF, 425 KB, 2005)
This research seeks to provide design guidelines that enable mine planning engineers to correctly assess the safety risk of an adverse multiple seam mining interaction based on mine geometry factors, mine layout factors and site specific geologic conditions.

Feasibility of Using Laser-Based Vibration Measurements to Detect Roof Fall Hazards in Underground Mines (PDF, 369 KB, 2002)
This paper looks at the feasibility of using noncontact laser-based vibration measurements to detect roof fall hazards with the ultimate vision of improving, expanding and automating procedures for mine roof inspection.

FLAC Simulation of Split-Pipe Tests on an Instrumented Cable Bolt (PDF, 686 KB, 2002-04)
Researchers have conducted a large number of experiments on cable bolts to determine their load characteristics for different grout types, grout ratios, and cable configurations (Garford bulb, buttons, birdcage, nut cage, etc.)

Forecasting Roof Falls with Monitoring Technologies - A Look at the Moonee Colliery Experience (PDF, 195 KB, 2005)
Monitoring technology and techniques can provide a means to warn of hazardous roof fall conditions. Measuring roof deflection is the most common method of detecting roof instabilities.

Investigation of Electromagnetic Emissions in a Deep Underground Mine (PDF, 275 KB, 2004-08)
Field studies were conducted to record electromagnetic (EM) emissions at the Galena Mine, Wallace, Idaho. The goal of the research was to determine if EM emissions were valid precursors to imminent ground failure.

The Long-term Performance of Surface Support Liners for Ground Control in an Underground Limestone Mine (PDF, 566 KB, 2003-08)
The purpose of this paper is to evaluate the preliminary findings of a long-term underground study of various types of surface support liners, and to examine installation practices that are critical for an effective liner material application.

Mechanics of a Large, Strain-Type Rock Burst and Design for Prevention (PDF, 278 KB, 2002-07)
A case study of a rock burst was conducted as part of a project to reduce rock burst hazards being undertaken by the Spokane Research Laboratory (SRL) of the National Institute for Occupational Safety and Health (NIOSH).

A Method for Modeling Variation of In Situ Stress Related to Lithology (PDF, 194 KB, 2001-07)
Assuring ground control safety in many mining and tunneling projects depends, at least in part, on an understanding of in situ stress conditions that will be encountered.

Multiple Seam Longwall Mining in the U.S. - Lessons for Ground Control (PDF, 658 KB, 2007)
Relatively few longwall mines in the U.S. operate under multiple seam conditions where the two seams are less than 200 ft apart. This paper describes the experience of six that do. These operations are located in PA, WV and UT, and include examples of both undermining and overmining. Some operate above or beneath their own workings, others are in historic mining districts and must contend with abandoned mines that are decades old.

Origin of Mining-Induced Fractures Through Macroscale Distortion (PDF, 905 KB, 2004)
NIOSH researchers have identified a pattern of fracture zone development that suggests an explanation for fracture formation around rectangular openings in underground mines.  Two computer modeling codes were used to model different aspects of this pattern.

Overview of Coal Mine Ground Control Issues in the Illinois Basin (PDF, 615 KB, 2008)
NIOSH has been actively gathering ground control information in the Illinois Basin in an effort to understand and control difficult mining conditions and has documented best practices for screen installation which has resulted in safe, efficient operations.

Preventing Injuries Caused by Unrecognized Stone Mine Roof Beam Failures With a Pro-Active Roof Control Plan (PDF, 2506 KB, 1999)
To help mitigate the potential for falls of ground injuries to underground stone miners, NIOSH developed the Roof Monitoring Safety System (RMSS) to aid in monitoring dangerous levels of roof beam deflection. If enough site-specific information is collected and placed on highly visible maps, individual mining operations could establish general guidelines for responding to specific roof beam deflection occurrences. This would help in implementing a pro-active, comprehensive roof control plan for reducing falls of ground injuries.

Proceedings: New Technology for Ground Control in Retreat Mining (PDF, 5087 KB, 1997-03)
This proceedings volume contains papers presented at technology transfer seminars sponsored by the National Institute for Occupational Safety and Health (NIOSH) on New Technology for Ground Control in Retreat Mining.

Reducing Roof Fall Accidents on Retreat Mining Sections (PDF, 4007 KB, 2005-12)
Since the end of 2000, there have been 28 ground fall fatalities in U.S. coal mines. Of these, 10 occurred during pillar recovery operations. Although pillar recovery has been associated with about one-third of recent ground fall fatalities, it accounts for only about 10% of U.S. underground coal production. Statistically, a coal miner engaged in pillar recovery is several times more likely to be killed in a ground fall than a miner on an advancing section of a longwall. This article describes the most significant risk factors associated with pillar recovery and prescribes control techniques that, taken together, can reduce the overall risk to miners.

Seismic Event Data Acquisition and Processing: Distribution and Coordination Across PC-Based Networks (PDF, 1539 KB, 2002-02)
NIOSH has developed an automated PC-based seismic event (induced earthquake) monitoring system for use in mine ground control studies. This paper describes the system's design philosophy, hardware and software components, examples of installations, and a few observational results.

Shear Mechanism for Mining-Induced Fractures Applied to Rock Mechanics of Coal Mines (PDF, 5625 KB, 2002)
Two examples of an echelon mining-induced fractures seen in hard-rock mines provided a basis for inferring that fracture zones and bedding plane sap rations immediately surrounding mine openings are promoted by oblique shear into the openings.

Technology News 443 - Design Practices for Multiple-Seam Room-and-Pillar Mines (PDF, 66 KB, 1994-11)
Room-and-pillar operators are provided with practical information and guidelines concerning multiple-seam mine design to reduce ground problems associated with the interaction of adjacent workings.

Technology News 529 - New Technology for Ground Control in Multiple-Seam Mining (PDF, 224 KB, 2007-11)
Research by NIOSH on multiple-seam mining has resulted in two new ground control products. The first is IC 9495 which is a proceedings document containing a variety of papers that summarize recent knowledge about multiple-seam mining. The second is the Analysis of Multiple-Seam Stability (AMSS) software package which is a simple user-friendly computer program to help mine planners. This document briefly describes each product.

Workplace Solutions: Ground Fall Injuries in Underground Stone Mines (PDF, 1255 KB, 2003-11)
Workers in underground stone mines have a high fatality rate caused by falls of ground from the mine roof or rib. NIOSH recommendations to reduce ground fall injuries and deaths address baskets, mechanical scalers, mechanical bolters, drill steel changing, personal protective equipment, and training.

Administrative controls

Geology, Ground Control, and Mine Planning at Bowie Resources, Paonia, CO (PDF, 457 KB, 2006)
Bowie Resources maintains one of the most pro-active ground control programs in the U.S. mining industry today. Its guiding philosophy is that everyone in the organization, from the miners at the face all the way through the top management, are involved in ground control. This paper will describe the program in detail, discussing the involvement of roof bolters, section foremen, surveyors, technical staff, and production managers. It will also show how the program has contributed to the mine planning process.

Videos

Hidden Scars
Zen and the Art of Rockbolting features a "master miner" who has worked underground for nearly 40 years. The main theme is to work safely AND efficiently.

Zen and the Art of Rockbolting
A story of survival and recovery, Hidden Scars is an interview with veteran hard rock miner Don Capperelli. Don recounts the events surrounding a 1994 rock burst that buried him and his partner, killing his partner and severely injuring him. A study in both mining safety and mining culture, Hidden Scars will touch even the most hardened worker.

Laboratories

Safety Structures Testing Laboratory
Large scale material and structural testing to prevent roof and rib falls.

Facilities

Simulated Underground Mine Facility
A simulated borehole and underground coal mine entry for studying mining techniques and processes.