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Articles 1 - 11 of 11
Full-Text Articles in Mining Engineering
Using Lamodel To Analyze Coal Bumps, Keith A. Heasley, Ihsan Berk Tulu
Using Lamodel To Analyze Coal Bumps, Keith A. Heasley, Ihsan Berk Tulu
Faculty & Staff Scholarship
Coal bumps have long been a safety hazard in coal mines, and even after decades of research, the exact mechanics that cause coal bumps are still not well understood. Therefore, coal bumps are still difficult to predict and control. The LaModel program has a long history of being used to effectively analyze displace- ments and stresses in coal mines, and with the recent addition of energy release and local mine stiffness calculations, the LaModel program now has greatly increased capabilities for evaluating coal bump potential. This paper presents three recent case histories where coal stress, pillar safety factor, energy release …
Vertical Stress And Stability Of Interburden Over An Abandoned Pillar Working Before Upward Mining: A Case Study, Jinwen Bai, Guorui Feng, Shanyong Wang, Tingye Qi, Jian Yang, Jun Guo, Zhen Li, Xianjie Du, Zehua Wang, Yunlou Du, Yujiang Zhang
Vertical Stress And Stability Of Interburden Over An Abandoned Pillar Working Before Upward Mining: A Case Study, Jinwen Bai, Guorui Feng, Shanyong Wang, Tingye Qi, Jian Yang, Jun Guo, Zhen Li, Xianjie Du, Zehua Wang, Yunlou Du, Yujiang Zhang
Faculty & Staff Scholarship
Upward mining of the residual coal seam over an abandoned pillar working is one of the effective measures to alleviate the contradiction between limited resources and increased consumption. Interburden stability over an abandoned pillar working plays a significant role in guaranteeing the safety of upward mining; however, it has not yet been extensively studied and understood. In this study, the vertical stress of the interburden over an abandoned pillar working was first investigated. The mechanical model of the interburden was established and the damage conditions were analysed. Then, the stability of the interburden over 38502 abandoned workings in Baijiazhuang coal …
Numerical Analysis And Case Study On The Mitigation Of Mining Damage To The Floor Of No. 5 Coal Seam Of Taiyuan Group By Grouting, A. Li, Y. Liu, L. Mou, K. Li
Numerical Analysis And Case Study On The Mitigation Of Mining Damage To The Floor Of No. 5 Coal Seam Of Taiyuan Group By Grouting, A. Li, Y. Liu, L. Mou, K. Li
Faculty & Staff Scholarship
Based on the geological condition of panel 22507 of the no. 5 coal seam at Dongjiahe coal mine, numerical analysis of the stability and water permeability of the floor aquiclude before and after grouting was conducted using Rock Failure Process Analysis (F-RFPA2D). The dynamic development, extension, and distribution of the cracks in the aquiclude are discussed. It is shown that grouting can increase the effective thickness of the aquiclude, reduce the floor damage depth, and control the floor water inrush path, thus effectively improving the overall strength and water blocking capability of the aquiclude. These numerical study results were applied …
Dynamic Mechanical Behavior Of Dry And Water Saturated Igneous Rock With Acoustic Emission Monitoring, Jun Guo, Guo-Rui Feng, Ting-Ye Qi, Pengfei Wang, Jian Yang, Zhen Li, Jinwen Bai, Xianjie Du, Zehua Wang
Dynamic Mechanical Behavior Of Dry And Water Saturated Igneous Rock With Acoustic Emission Monitoring, Jun Guo, Guo-Rui Feng, Ting-Ye Qi, Pengfei Wang, Jian Yang, Zhen Li, Jinwen Bai, Xianjie Du, Zehua Wang
Faculty & Staff Scholarship
The uniaxial cyclic loading tests have been conducted to study the mechanical behavior of dry and water saturated igneous rock with acoustic emission (AE) monitoring. The igneous rock samples are dried, naturally immersed, and boiled to get specimens with different water contents for the testing. The mineral compositions and the microstructures of the dry and water saturated igneous rock are also presented. The dry specimens present higher strength, fewer strains, and rapid increase of AE count subjected to the cyclic loading, which reflects the hard and brittle behavior and strong burst proneness of igneous rock. The water saturated specimens have …
Analysis Of Monitored Ground Support And Rock Mass Response In A Longwall Tailgate Entry, G.S. Esterhuizen, D.F. Gearhart, I.B. Tulu
Analysis Of Monitored Ground Support And Rock Mass Response In A Longwall Tailgate Entry, G.S. Esterhuizen, D.F. Gearhart, I.B. Tulu
Faculty & Staff Scholarship
A comprehensive monitoring program was conducted to measure the rock mass displacements, support response, and stress changes at a longwall tailgate entry in West Virginia. Monitoring was initiated a few days after development of the gateroad entries and continued during passage of the longwall panels on both sides of the entry. Monitoring included overcore stress measurements of the initial stress within the rock mass, changes in cable bolt loading, standing support pressure, roof deformation, rib deformation, stress changes in the coal pillar, and changes in the full three-dimensional stress tensor within the rock mass at six locations around the monitoring …
Geotechnical Considerations For Concurrent Pillar Recovery In Close-Distance Multiple Seams, Peter Zhang, Berk Tulu, Morgan Sears, Jack Trackemas
Geotechnical Considerations For Concurrent Pillar Recovery In Close-Distance Multiple Seams, Peter Zhang, Berk Tulu, Morgan Sears, Jack Trackemas
Faculty & Staff Scholarship
No abstract provided.
Deep Cover Bleeder Entry Performance And Support Loading: A Case Study, Ted M. Klemetti, Mark Alexander Van Dyke, Ihsan Berk Tulu
Deep Cover Bleeder Entry Performance And Support Loading: A Case Study, Ted M. Klemetti, Mark Alexander Van Dyke, Ihsan Berk Tulu
Faculty & Staff Scholarship
Several questions have emerged in relation to deep cover bleeder entry performance and support loading: how well do current modeling procedures calculate the rear abutment extent and loading? Does an improved understanding of the rear abutment extent warrant a change in standing support in bleeder entries? To help answer these questions and to determine the current utilization of standing support in bleeder entries, four bleeder entries at varying distances from the startup room were instrumented, observed, and numerically modeled. This paper details observations made by NIOSH researchers in the bleeder entries of a deep cover longwall panel—specifically data collected from …
Analysis Of Global And Local Stress Changes In A Longwall Gateroad, I.B. Tulu, G.S. Esterhuizen, D. Gearhart, T.M. Klemetti, K.M. Mohamed, D.W.H. Su
Analysis Of Global And Local Stress Changes In A Longwall Gateroad, I.B. Tulu, G.S. Esterhuizen, D. Gearhart, T.M. Klemetti, K.M. Mohamed, D.W.H. Su
Faculty & Staff Scholarship
A numerical-model-based approach was recently developed for estimating the changes in both the hor- izontal and vertical loading conditions induced by an approaching longwall face. In this approach, a sys- tematic procedure is used to estimate the model’s inputs. Shearing along the bedding planes is modeled with ubiquitous joint elements and interface elements. Coal is modeled with a newly developed coal mass model. The response of the gob is calibrated with back analysis of subsidence data and the results of previously published laboratory tests on rock fragments. The model results were verified with the sub- sidence and stress data recently …
Hydrogeology And Water Management In The Arkwright Underground Coal Mine, Pittsburgh Seam, Northern West Virginia, Bryant D. Mountjoy
Hydrogeology And Water Management In The Arkwright Underground Coal Mine, Pittsburgh Seam, Northern West Virginia, Bryant D. Mountjoy
Graduate Theses, Dissertations, and Problem Reports
Arkwright #1 is a closed underground mine in the Pittsburgh coal seam near Morgantown, West Virginia USA. Arkwright shares perimeter boundaries/barriers with three other closed Pittsburgh seam mines (Osage #3, Jordan #93, Federal #1) and is partially overlain by flooded Sewickley seam mines, 25 m above it. This mine is significant primarily because it manages and treats water diverted from nearly 20 other closed mines over a 600 square kilometer area. This study examines water levels, pump records, and mine maps to describe the hydrogeology of Arkwright Mine. After closure in 1995, Arkwright and the adjacent northern Osage mines began …
Shale Characterization And Size-Effect Study Using Scanning Electron Microscopy And X-Ray Diffraction, Debashis Das
Shale Characterization And Size-Effect Study Using Scanning Electron Microscopy And X-Ray Diffraction, Debashis Das
Graduate Theses, Dissertations, and Problem Reports
Ground failure is a major contributor of the total fatalities in underground mines in the US. Underground coal mines in the Northern Appalachian region have weak roof rock mainly composed of shale and sandstone. Characterization of shale is indispensable for developing an effective ground control plan. However, this has not been done extensively. This thesis attempts to address this issue. It investigates the variation in mechanical properties of shale with variation in size. In addition, an attempt has been made to relate the strength of shale with its petrographic parameters. X-ray diffraction technique was used to estimate the compositional parameters …
Parametric Study Of Coal Liberation Behavior Using Silica Grinding Media, Adewale Wasiu Adeniji
Parametric Study Of Coal Liberation Behavior Using Silica Grinding Media, Adewale Wasiu Adeniji
Graduate Theses, Dissertations, and Problem Reports
This study evaluates the coal liberation behavior using silica as the grinding media by assessing the effects of four operating factors including nominal feed size, media size, shaft speed and grinding time, each of three levels on two response variables, the product P80 and the specific energy. The coal material used in this study was mixed-phase particles commonly referred to as middlings, sampled from dense medium circuit at the Leatherwood preparation plant in Kentucky. One-third fractional factorial design of resolution III was implemented. Since silica was obtained in three standard size ranges as per manufacturer’s design, media size was …