Mining Contract: Demonstration of the Ability of Distributed Fiber Optic Sensing Technologies to Enhance Mine Safety

Contract #	211-2014-59580
Start Date	7/15/2014
Research Concept	As a result of technology-enabled early warnings and community response systems, the loss of human life in hurricanes, tornadoes, and tsunamis, among other natural disasters, is declining. Similar early detection of rock movement signaling imminent underground space or pit wall collapse in mines has the potential to prevent loss of life and serious injuries from mine disasters.
Topic Area	Ground Monitoring

Contract Status & Impact

This contract is ongoing. For more information on this contract, send a request to mining@cdc.gov.

Aside from recently developed real-time radar systems that have been used to observe patterns of displacement of the ground surface (e.g., pit slopes), the state-of-the-art in geotechnical and seismic monitoring is essentially limited to localized point measurements. The possibility exists that distributed fiber-optic technologies can be used for structural health monitoring in mines, providing early detection of rock movement. A network of fiber-optic cable is envisioned that can reliably detect ground deformation, temperature anomalies, and even dynamic events as a technologically advanced tool for enhancing safety and preventing catastrophic disasters. This network could be monitored continuously and could provide continuous coverage throughout the mine. Based on recent results from preliminary deployments, Montana Tech of the University of Montana has evidence that fiber-optic cable can be deployed and monitored in a cost-effective manner and provide real-time data needed to keep mine personnel safe.

This contact research is to use fiber-optic-based technology to allow distributed sensing of temperature, deformation, and dynamic events, which will enable much more comprehensive monitoring than is available with current geotechnical and seismic monitoring instruments. The primary goal of this research is to demonstrate the effectiveness of the emerging fiber-optic-based distributed strain and temperature (DST) and distributed acoustic sensing (DAS) technologies under various mining conditions, facilitating their adoption by the mining industry and thereby contributing to mine safety.

Specific objectives are to demonstrate that DST technology (a) can be employed in an underground mine, attached to rock surfaces and in boreholes, to reliably and accurately detect ground deformation of different characters, and (b) can be used to monitor temperature profiles when deployed along rock surfaces, in boreholes, and submerged in flooded shafts. The DAS component of this research aims to investigate (a) what ground motion and waveform information is obtainable, and (b) how sensor arrays consisting of fiber-optic cable can improve the ability to detect and locate subsurface vibrations. This technology can benefit the mining industry through enhanced monitoring of blasts, rockbursts and “bumps,” and microseismic events that may be associated with impending ground control problems.

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