Research by the National Institute for Occupational 

Safety and Health (NIOSH) on multiple-seam mining 

has resulted in two new ground control products. 

Information Circular (IC) 9495 

In some U.S. coalfields, particularly in central Appalachia and the West, most 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. These can seriously threaten 

the safety of miners and disrupt mining operations. 

 Information Circular (IC) 9495 is a proceedings 

document containing a variety of papers that summarize 

recent knowledge about multiple-seam mining. A 

NIOSH study that analyzed case histories collected from 

44 U.S. coal mines is described in detail. The study 

confirmed that overmining is much more difficult than 

undermining, and isolated remnant pillars cause more 

problems than gob-solid boundaries. The study’s results 

were the basis for the Analysis of Multiple-Seam Stability (AMSS) software package. 

The proceedings also contain two papers describing 

the LaModel family of software. The original threedimensional version of LaModel is essential for detailed 

analyses of complex multiple-seam scenarios. LaM2D 

implements a simplified, two-dimensional model suitable for quick approximations of the multiple-seam 

stresses and strains. 

Three papers in the proceedings focus on case 

histories. One describes the extensive multiple-seam 

experience at the Harris No. 1 Mine in West Virginia, 

a second contains examples of “extreme” multiple-seam 

mining from the central Appalachian coalfields, and a 

third describes interactions with regard to 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. 

No. 529 November 2007 

New Technology for Ground Control in Multiple-Seam Mining 

AMSS Software Package 

NIOSH has developed a simple, user-friendly computer 

program called Analysis of Multiple-Seam Stability 

(AMSS). AMSS can help mine planners to evaluate each 

potential multiple-seam interaction and take steps to reduce 

the risk of ground control failure. 

AMSS begins by evaluating the pillar design. It first 

calculates the single-seam pillar stability factor (SF) 
 

using the familiar Analysis of Longwall Pillar Stability 

(ALPS) or Analysis of Retreat Mining Pillar Stability 

(ARMPS) method. Then it automatically generates a 

numerical model that provides the additional multipleseam stress. If the final multiple-seam SF seems 

inadequate, then AMSS warns that the pillar size should 

be increased. 

Next, AMSS predicts the severity of the potential 

interaction in terms of three risk levels: 

•	 Green (where a major multiple-seam interaction is considered unlikely); 

•	 Yellow (where adding a pattern of cable bolts or 

other equivalent supplemental support could 

greatly reduce the probability of a major interaction); or 

•	 Red (a major interaction should be considered 

likely, and it may be desirable to avoid the area 

entirely). 

AMSS can then be used to analyze the effects of installing supplemental support, reducing the entry width, 

eliminating crosscuts, or increasing the entry spacing. 

For More Information 

IC 9495 may be downloaded from the NIOSH Mining 

Web site at http://www.cdc.gov/niosh/mining/pubs/ 

pubreference/outputid2436.htm. The AMSS software may be downloaded at http://www.cdc.gov/ 

niosh/mining/products/product154.htm. You may 

also order a copy of IC 9495 and/or the AMSS software by 

sending an e-mail to: pithealth@cdc.gov. Or you may 

complete the order form below, detach, and mail to: Office 

of the Director, Health Communications, NIOSH Pittsburgh 

Research Laboratory, P.O. Box 18070, Pittsburgh, PA 

15236–0070, or fax to (412) 386–6780. 

To receive NIOSH documents or for more information 

about occupational safety and health topics, contact: 

1–800–CDC–INFO (1–800–232–4636), 1–888–232– 

6348 (TTY), e-mail: cdcinfo@cdc.gov, or visit the 

NIOSH Web site at http://www.cdc.gov/niosh 

Mention of any company name or product does not constitute endorsement by the National Institute for Occupational Safety and Health. 

The Analysis of Multiple-Seam Stability (AMSS) software start screen. 

DHHS (NIOSH) Publication No. 2008–103 

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G Please send me a copy of IC 9495, “Proceedings: New Technology for Ground Control in Multiple-Seam Mining.” 

G Please send me a copy of the Analysis of Multiple-Seam Stability (AMSS) software. 

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