Abstract
The safety monitoring of coal roadways roof is the key to prevent roof accidents and ensure coal mines safety. However, the monitoring blind zones caused by traditional methods is one of the main reasons of frequent roof accidents. To ensure the safety of coal mines production, a novel roof monitoring method is proposed in this paper, which is based on the distributed optical fiber sensing (DOFS) and the pre-stretched optical fiber layout at fixed points (POFLF). The research of this approach has been carried out through analysis of DOFS optical fiber strain monitoring and POFLF theory, and with the help of indoor optical fiber strain experiment. Finally the approach was applied in the field monitoring of a coal roadway roof. Aforementioned verified the optical fiber strain distribution not only accurately indicate the roof settlement range, but also qualitatively and quantitatively demonstrate the roof subsidence displacement. The feasibility and validation of the approach as a supplementary or auxiliary resorts in roof safety monitoring were confirmed. The research in this paper not only has important reference significance for the safety monitoring of coal roadways roof under similar geological and production conditions, but be of helpful for improving the coal mine safety as well.
Highlights
Coal roadway roof collapse accidents are the most common and frequent accidents
According to statistics from the State Administration of Coal Mine Safety (SACMS) for more than ten years, coal mine roof accidents accounted for 51.2% of the total number of coal mine accidents, while the death toll caused by coal mine roof accidents accounted for 36.5% of the total death toll [1]
The specific laying processes of optical cables along the roof are as follows: (1) Selecting the monitoring area and initial laying out of optical cable; (2) Fixing the fixture to the exposed end of the anchor cables with anchor cable locks; (3) Fastening clamps with the optical cable tightly compressed to the tray of the fixture; (4) Adjusting the screw and anchor lock and pre-stretching the fixed cable horizontally; (5) Testing the passing path of the optical fiber; later fusing the Steel Strand (SS) optical cables with the common telecom optical cables; laying out the telecom cables to the main roadway’s observation where it was connected to the Brillouin optical time domain reflectometry (BOTDR) av6419
Summary
Coal roadway roof collapse accidents are the most common and frequent accidents. According to statistics from the State Administration of Coal Mine Safety (SACMS) for more than ten years, coal mine roof accidents accounted for 51.2% of the total number of coal mine accidents, while the death toll caused by coal mine roof accidents accounted for 36.5% of the total death toll [1]. The cruel reality and severe coal mine safety production situation make it very urgent and imperative that a new distributed monitoring technology without monitoring blind area and monitoring omission point must be explored to effectively monitor the safety of coal roadway roof. It is only the Distributed optical fiber sensing (DOFS) technology which emerged in the 1980s is just the kind of techniques the coal mines need utmost urgently. A new approach based on DOFS combined with pre-stretched optical fiber layout at fixed-points (POFLF) is proposed for realizing the distributed settlement monitoring of coal roadways roof. According to the length of the fiber after deformation, other geometric parameters of the fiber deformation can be calculated by using the geometric principle
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
