Sponsor agency:
ALPHA FOUNDATION FOR THE IMPROVEMENT OF MINE SAFETY AND HEALTH
Amount:
$560,000
Term:
Dec, 2016 to Dec 2018
Description:
Post-accident emergency communications and tracking (C&T) systems are now installed in all underground coal mines, as required by the Mine Improvement and New Emergency Response Act (MINER Act) of 2006. However, many questions remain about whether C&T installations will survive catastrophic events, as intended by the MINER Act. To date, no in-depth testing has occurred to answer these questions or to make recommendations to help ensure the operational survival of these systems. The proposed research will investigate through testing the forces and hostile environments created by catastrophic events, particularly explosions, and roof falls (impacts), and their effects on C&T systems. Additionally, practical measures will be investigated and recommend to improve survivability based on these findings.
Sponsor agency:
Centers for Disease Control and Prevention/ National Institute for Occupational Safety and Health (NIOSH)
Amount:
$428,903
Term:
August 2017 to August 2019
Description:
Underground coal mine explosions can be addressed using two perspectives: a) Prevention and b) Mitigation. The U.S. mining industry practices have emphasized on preventing explosions in underground coal mines, with little being done in mitigating the explosion once it occurs. Despite successful practices for the prevention of underground coal mine explosions in the U.S., the threat of an explosion does still exist. Other mining countries have been working towards developing mitigation techniques such as active explosion barriers. In the late 1990s the United State Bureau of Mines carried out comprehensive research in the use of active explosion barrier systems in the US; however, currently their use is not popular, and research in this matter is required. The proposed work will explore in a practical way through scale and full-scale testing different active explosion barrier systems to be adapted and modified for their use in the U.S. coal mining industry.
The results of this project will enhance the safety of the miners, with the implementation of active explosion barrier systems for the specific geological and technological conditions in the underground coal mines in the U.S. The use of active barrier systems, will mitigate and reduce the extension of the area affected by an accidental explosion in underground coal mines.
Sponsor agency:
Centers for Disease Control and Prevention/ National Institute for Occupational Safety and Health (NIOSH). (NIOSH contract 200-2014-60047)
Amount:
$299,773
Term (Completed):
August 2014 to August 2016
Description:
The work performed during the project includes the analyses of various mine accidents, yielding the conclusion that for this research, the 15 psi pressure-time curve could be adapted for testing the compressed air lines. Flying debris impacting the compressed air lines is an important variable to consider in this project. A series of explosion tests were conducted at the UKERT lab in the shock tube using varying quantities of explosives and standoffs. The most severe recorded value at the shock tube during the testing stage was a peak pressure value of 150 psi. No cases were observed where damage to the pipes or to the anchorage elements occurred. A Hopkinson Bar (HB) device was modified to test the compressed air lines for flying debris. Several tests were performed using the modified (HB) to find the level of kinetic energy of the element impacting the compressed air line required to break the pipes (puncture). Energy levels. Energy levels required to break the pipes ranged from 9,000 to 56,000 K joules. The variation in kinetic energy to break the pipe was determined by the type and thickness of pipe material. Various hardening techniques were explored to protect the compressed air lines in the modified HB. Sand, gravel, concrete and conveyor belt were tested as protective materials. Promising results were obtained for a combination of concrete and conveyor belt materials.
Student:
Russell Lamont
Description:
Use of discrete element methods (DEM) to model cast blast events for mining applications. This research explores the different available DEM tools for modeling cast blast events to better predict the final cast geometry and optimize the cast blast design. The research will generate a 2D algorithm (application) for cast blast modeling. Dynamic properties of the rock mass will be included in the analysis using the hose made Hopkinson bar apparatus. Field information from the rock mass geometry will be collected using photogrammetry techniques. Fragmentation and final geometries of actual cast blast events will be survey using unmanned air vehicle (UAV) technology. It is expected to finish this research by Dec 2019.
Student:
Nathaniel Schaefer
Description:
This research will explore the different aspects of fracture generation, propagation and extension for blasting applications. Several commercial codes and in-house algorithms will be used in the research. New modeling techniques such as the finite-discrete element method will be explored. Dynamic properties of the rock will be included in the analyses. Full scale and scaled model techniques will be used for the calibration of the numerical models. As a result of the research it is expected the formulation of a novel methodology for the easy assessment of the extent of damage produced by a blast in mining applications. It is expected to finish this research by August 2020.
Student:
Tristan Worsey
Description:
The control of ground vibration levels using timing is understood through the use of signature hole techniques or wave superposition techniques. However, the effects of timing and the firing sequence of the shot has not been correlated with the final fragmentation result. This research will explore the fragmentation in mine blasting as a function of timing and firing sequence. Dynamic properties of the rock mass will be included in the analysis using the in-hose made Hopkinson bar apparatus. Field information from the rock mass geometry will be collected using photogrammetry techniques. Fragmentation and final geometries of actual cast blast events will be survey using unmanned air vehicle (UAV) technology. It is expected to finish this research by Dec 2018.
Researcher (Visiting Scholar-China University of Mining & Technology-Beijing):
Fei Liu
Description:
This joint research will explore the analysis of rock burst (coal bump) for underground mine applications. Coal samples has been collected for the determination of its dynamic properties in the in-house made Hopkinson Split Bar. Numerical analysis using dynamic properties will explore the mechanisms of rock burst (coal bump). It is expected to finish the first stage of this research by Sept 2018.