Annual Meeting Preliminary Program - Full Brochure (PDF) - SME

TECHNICAL PROGRAM
10:25 AM
Environmental Impact of Loading Equipment in Surface
Coal Mining
A. Lashgari and V. Kecojevic; Mining Engineering, West Virginia
University, Morgantown, WV
This paper presents a research results on assessment of environmental impact of
loading equipment in surface coal mining. Environmental impact is accessed
through the equipment exhaust emissions, dust generation and noise level.
Loading equipment include hydraulic front shovel, hydraulic backhoe shovel and
wheel loader. Exhaust emissions are related to carbon dioxide (CO2), carbon
monoxide (CO), nitrogen oxides (NOx), sulfur oxides (SOx), and volatile organic
compounds (VOCs). Dust generation is expressed through the particulate matter
(PM10) and total suspended particulate matter (TSP), while noise level is presented
through the acoustic power level. This research is a part of a broader project
on development of software system for the selection of productive, cost-effective
and eco-friendly mining systems, which is sponsored by the Appalachian
Research Initiatives for Environmental Sciences (ARIES).
chair:
9:00 AM
Introductions
coal & energy:
the best of Ground control
9:00 AM • Wednesday, February 27
S. Tadolini, Minova, Georgetown, KY
9:05 AM
A Stability Factor for Supported Mine Entries Based on Numerical
Model Analysis
E. Esterhuizen; NIOSH, Office of Mine Safety and Health,
Pittsburgh, PA
At present, support design methods include empirical methods based on observations
of past performance of installed support systems, analytical methods where
the roof is typically simulated by elastic beams and numerical model analysis.
The approach estimates the relative stability of a support design through geotechnical
evaluation of the rock mass and numerical model analysis of the interaction
between the rock mass and the support system. Models are used first to simulate
the design performance at the expected rock conditions. The rock strength is then
reduced until collapse is indicated in the model. The stability factor is then calculated
as the ratio of the expected rock mass strength to the rock mass strength at
the onset of collapse, and is similar to the well-known factor of safety used in engineering
practice. The stability factor can be used to assist in developing a final
support design by comparing the effectiveness of various support systems and the
stability of excavations under various geological and loading conditions.
9:25 AM
Ultra-Close Multiple Seam Mining Analysis and Verification
D. Su, L. Stull, M. Jamie and J. Lu; CONSOL Energy Inc.,
Canonsburgh, PA
This presentation presents the results of a detailed geotechnical study on the potential
multiple seam interaction between the No. 2 Gas (upper) and the
Powellton seams, which are separated by an average interburden of 45 ft. To evaluate
the potential interaction between the two mine works and to determine the
pillar safety factor, Analysis of Multiple Seam Stability (AMSS) software was initially
used to determine pillar dimensions to obtain a minimum safety factor of
2.0 for areas under pooled water, as well as a minimum safety factor of 1.5 for
areas not under pooled water. Furthermore, to assess the quality of the interburden
rock strata, two surface core holes were drilled, and rock cores were tested in
the laboratory for their strength and elastic moduli. Using the experimentally determined
strengths and moduli as part of the input parameters, the RocScience
Phase2 finite element program was employed to model the stress field scenarios
and estimate the safety factors of the interburden rock strata before and after
Powellton seam mining.
9:45 AM
Applications of Microseismic Monitoring in China’s Underground
Coal Mines
Z. Hosseini 1 , X. Wu 1 , C. Li 2 and C. Trifu 1 ; 1 ESG Solutions, Kingston,
ON, Canada and 2 University of Science & Technology, Xi’an, China
Longwall and continuous mining are prevalent methods employed by Chinese
underground coal operations. The main ground control challenges include roof
skin deformation, roof collapse, and outbursts of coal, gas, and water.
Microseismic monitoring provides valuable information on rockmass behavior
and fracture propagation caused by stress redistribution, active geological structures,
or gas build up within the coal strata and the surrounding rockmass.
Collecting and assessing seismic data has proven to be an instructive tool for engineers
to better assess ground conditions and mitigate seismic hazards associated
with mining. The development of intrinsically safe and explosion proof certified
seismic monitoring equipment has revolutionized Chinas underground
coal mines. The use of this technology allows for the optimization of gas
drainage at an increased rate of two at a 50% higher purity without any increase
in drilling costs. Microseismic monitoring can also be used in identifying seismically
active faults and shear zones. This information can be used to assess and revise
mining strategies to improve safety and ground stability.
10:05 AM
Requirements and Performance of Pumpable Cribs in Longwall
Tailgate Entries and Bleeders
P. Zhang, M. Milam, M. Mishra, W. Hudak and R. Kimutis; Alpha
Natural Resources, Waynesburg, PA
Pumpable cribs are being increasingly used in longwall tailgate entries and bleeders
for roof support under abutment pressure. Their high peak capacity and confinement-controlled
yield characteristics from reinforced-bags make them relatively
safe and reliable standing supports for highly productive longwall panels.
The pumpability of crib material over a long distance from the surface greatly reduces
material handling and makes the underground installation more efficient
and flexible. However, the performance of pumpable cribs is dependent upon crib
properties, crib pattern, quality of installation, and geological and mining conditions.
For proper crib selection and safe support design, it is critical to understand
the basic technical requirements and performance of pumpable cribs in longwall
tailgate entries and bleeders. Based on more than 10 years of experience using
pumpable cribs for longwall standing support, the requirements and performance
of pumpable cribs in longwall tailgate entries and bleeders under different mining
conditions are presented.
10:25 AM
Passive Seismic Imaging for Determination of the Longwall Rear
Abutment Location
E. Westman 1 , J. Kerr 2 , K. Luxbacher 1 and S. Schafrik 1 ;
1
Virginia Tech University, Blacksburg, VA and 2 Cliff Natural
Resources, Cleveland, OH
Few studies have been conducted regarding the location, movement, and relative
magnitude of the rear abutment of a longwall coal mine. The rear abutment, or
the abutment pressure arch in the gob area, is controlled primarily by the quality
of pack of the gob; the more compacted the gob is, the larger the stress would be
theoretically. While there is no definitive location for the rear abutment, early
studies showed that it could be located as far back in the gob as 300 m (1,000 ft).
Like the location of the rear abutment, there has been little research conducted
and very few answers as to the exact magnitude of the rear abutment load. The
objective of this study is to determine whether passive seismic tomography could
image the location, movement, and relative magnitude of the rear abutment as
the longwall face retreated, in addition to the forward abutment and gob.
10:45 AM
Impact of a Massive Sandstone Channel on a 1500 ft. Wide
Longwall Face
D. Su, G. Hasenfus, L. Stull, J. Lu, S. Morgan, P. Kelley and D.
Teeter; CONSOL Energy Inc, Canonsburg, PA
This presentation presents the implementation and evaluation of the hydraulic
fracturing technique and Longwall Visual Analysis (LVA) software to mitigate
the impact of a 1,000-foot (305-meter) wide massive sandstone channel on a
1,500-ft-wide (457-m-wide) longwall face. Based on a underground roof geology
reconnaissance program, four frac holes were drilled and fraced along the center
axis of the sandstone channel. To further provide detailed monitoring of the
longwall face, the Longwall Visual Analysis (LVA) software was installed to track
the face pressure and cavity formation index. In mid-December 2011, the long-
This is the Technical Program as of September 1, 2012. IT IS SUBJECT TO CHANGE.
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