Each year more than 400 coal miners are injured (fatal and non-fatal) by rock falling from between or around roof supports. Many of these injuries could be prevented by the installation of roof screen (wire mesh). However, many coal mines may be reluctant ...

Multiple seam interactions are a major ground control hazard in many U.S. underground coal mines. The two most common types are: Undermining, where stress concentrations caused by previous full extraction in an overlying seam is the primary concern, and Overmining, ...

The study site was a longwall tailgate subjected to a severe horizontal stress concentration. Field measurements indicated that the stresses applied to the study site nearly doubled during longwall mining, resulting in roof deformations extending to a height ...

This paper summarizes 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 used by suitably qualified colliery staff. The project was funded mainly by ...

This paper describes recent studies using short encapsulation pull tests in the U.S. The study found that the SEPT can be used to make a simple evaluation of resin bolt anchorage. Suggested procedures for conducting SEPT are included. The study also confirmed ...

Fatalities caused by highwall/spoilbank failure in the surface mines, coal and non-metal, increased to an alarming rate of seven during 1999. To determine the cause of slope failure and successful mining practice, the National Institute for Occupational Health ...

This paper presents an overview of the most significant ground control hazards facing today's mineworkers. Analysis of recent fatality investigations and accident statistics identified certain job categories, mining techniques, and geologic environments that ...

<p>Pillar design is the first line of defense against rock falls&mdash;the greatest single safety hazard faced by underground coal miners in the United States and abroad. To help advance the state of the art in this fundamental mining science, the National ...

This report presents results of a U.S. Bureau of Mines study of longwall gob material. The objective of this work was to determine material stiffness properties of the gob for use in numerical models of rock mass response to longwall mining. Photographs of ...