| GROUND CONTROL SOFTWARE FROM NIOSH
CDC/NIOSH took over mine safety
research when the U.S. Bureau of Mines was dissolved. Part of the work
done by the USBM was to develop software for underground coal
applications. The software can be applied for similar mines using a
room and pillar mining method. NIOSH has continued maintaining and
upgrading the software as well as developing new applications. Most
NIOSH Mining software is available for Microsoft Windows 98, NT, 2000
and XP operating systems. Mine analysis software available for
free download from the NIOSH Web site includes:
• Analysis of Longwall Pillar
Stability (ALPS)
• Analysis of Retreat Mining Pillar Stability (ARMPS)
• Coal Mine Roof Rating (CMRR)
• Analysis of Roof Bolt Systems (ARBS)
• Analysis of Horizontal Stress Effects in Mining (AHSM)
ALPS (Analysis of Longwall Pillar
Stability) is software for
designing pillars for longwall mines. The ALPS method, which is
embodied in the program, consists of three basic steps:
1. Estimating the loading that will be
applied to the pillars during all the phases of longwall mining
2. Estimating the load-bearing capacity of the longwall pillar system,
and
3. Calculating “stability factors” (SF) by comparing the load to
the load-bearing capacity
Since its development, the ALPS method
has been verified by back-analysis of more than 100 actual mining case
histories. This version of the software includes the Mark Bieniawski
pillar strength formula, which more accurately represent the strength
of rectangular pillars, and more flexibility in longwall layout by
allowing angled crosscuts and varied crosscut spacing.
ARMPS (Analysis of Retreat Mining
Pillar Stability) is software for designing pillars for
room-and-pillar retreat mining. ARMPS calculates stability factors
based on estimates of the loads applied to, and the load-bearing
capacities of, pillars during retreat mining operations. The program
can model the significant features of most retreat mining layouts,
including angled crosscuts, varied spacing between entries, barrier
pillars between the active section and old (side) gobs, and slab cuts
in the barriers on retreat. It also features a pillar strength formula
that considers the greater strength of rectangular pillars. The
program may be used to evaluate bleeder designs as well as active
workings.
CMRR (Coal Mine Roof Rating) is
software for estimating the relative inherent strength of coal mine
roof. The Coal Mine Roof Rating is a roof classification system that
was first introduced to the mining community in 1994. It filled a
longstanding need to quantify geologic description of coal measure
rocks into an engineering value which could be used for mining design
purposes. Rocks which form the roof of coal mines can vary widely and
quickly in composition, extent, and defects. This results in an
equally broad range of rock properties which can substantially affect
the ability of the rock mass to form a stable mine roof. The CMRR was
designed to evaluate the properties of the coal mine roof rock mass
which contribute to its’ weakness and convert them into a relative
strength rating from 0-100. These properties include the cohesion and
frequency of discontinuities like bedding, slips, shears, and joints,
UCS, and moisture sensitivity.
With simple laboratory and field tests
and observation, the CMRR can be calculated by technical and operating
personnel with a minimum of training. Originally designed to be used
with underground exposures, the CMRR can also be calculated from core.
The CMRR has found a wide range of applications. These include:
integration into ALPS and ALTS, the chain pillar design program for
longwall gateroads in both the U.S. and Australia; in the assessment
of the suitability of extended cuts; roof bolt selection; roof fall
evaluations; input for numerical models; and in tailgate support
guidelines.
ARBS (Analysis of Roof Bolt Systems)
is software to aid in the selection of roof bolts for primary
support in underground coal mines. Selecting the proper roof bolt
system from the immense variety of available bolt types and patterns
can be confusing. ARBS simplifies the process by collecting input on
the most important factors that determine the roof bolt performance,
including roof quality, depth of cover, and intersection span. Using
this information, ARBS suggests preliminary design values for bolt
length, capacity, and pattern. In addition to helping select primary
support patterns, ARBS can also indicate where supplemental support
may be needed.
Analysis of Horizontal Stress
Effects in Mining (AHSM) - It is now widely accepted that
horizontal stress is present nearly everywhere underground. Often it
is more severe than the vertical stress. It is a major cause of roof
control problems in underground mines. Horizontal stress is generally
more intense in some directions than others, so its effects can be
minimized with proper entry orientation. AHSM contains two modules to
improve mine layouts for control of horizontal stress. For
development, the user specifi es the orientations of the entries, the
crosscuts, and the maximum horizontal stress. Angled crosscuts may be
used, and the angles may be different for the right- and left-hand
crosscuts. If site-specific stress measurements are not available, a
drop-down menu allows the user to select from a menu of regional
stress orientations. AHSM then shows the how the stress condition
would vary as the entry and crosscut orientations are
changed.
The second module is for longwall
mining. Severe stress concentrations can make headgate conditions
hazardous when the entries are improperly oriented. AHSM shows whether
a particular longwall orientation and sequence of panel recovery
places the headgate corner in a stress concentration or in stress
relief. AHSM also estimates the magnitude of the stress
concentration.
Ground Control Toolbar - A new
feature is a toolbar that can be added to your desktop. The toolbar
provides easy access to ALPS, ARMPS, CMRR, ARBS, and AHSM. Installing
the Ground Control Toolbar will also install all the NIOSH Ground
Control analysis packages. The toolbar can be downloaded at: http://www.cdc.gov/niosh/mining/products/product41.htm
Other software available for mining
applications includes:
• Air Quantity Estimator (AQE)
• Analysis of Retreat Mining Pillar Stability (ARMPS)
• Stress and Displacement Calculations (LAMODEL)
• Spontaneous Combustion Expert System (SPONCOM)
• Support Technology Optimization Program (STOP)
• Vibrational Acceleration Statistical Analysis (VASA)
• LAMODEL and MULSIM/NL Pre-Processor (LAMPRE)
• LAMODEL post-processor (LAMPLT)
• Analysis of Retreat Mining Pillar Stability - Highwall Mining (ARMPS-HWM)
Most packages are downloadable from the
NIOSH Web site: http://www.cdc.gov/niosh/mining/products/.
Betty Gibbs is president of Gibbs
Associates, a consulting firm providing a variety of computer software
services for the mining industry. For more information, contact Gibbs
Associates, P.O. Box 706, Boulder, Colorado 80306-0706; phone &
fax at (303) 444-6032; Email: mining@miningsoftware.com;
www.miningsoftware.com.
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