Using G-652 optical fiber to control mountain massifes of coal mines

Introduction. The relevance of using fiber-optic sensors to monitor the geomechanical state of the mine workings of coal mines of the Karaganda coal-mining field is extremely high, because they are super-categorical and dangerous in a sudden explosion of coal dust and methane gas during mining operations in hazardous mines. Fiber optic sensors have several advantages: explosion safety, high accuracy, measurement speed and have good linearity of characteristics. Aim. The use of optical fiber of the ITU-T G.652.D standard as a sensor for monitoring the geomechanical state of an array of coal mines, which is very promising in terms of creating a distributed monitoring system capable of timely signaling to personnel about the danger of a sudden collapse of a mine. Materials and methods. To develop methods for monitoring and measuring the geotechnical parameters of the workings, a simulation laboratory bench based on fiber-optic sensors was developed. The authors used a quartz single-mode optical fiber 9/125 μm (OS2) Corning SMF-28e + ®. The article proposes systems in two variants, depending on the tasks and functionality. In the first variant, the well-known method of optical reflectometry OTDR (Optical time domain reflectometer) is used. In the second variant, the values of the additional losses caused by the mechanical action on the optical fiber are controlled. Results. During mechanical action on an optical fiber microcracks occur, leading to a change in the properties of light and an increase in additional losses of the light wave passing through it. Conclusion. The use of ITU-T G.652.D standard optical fiber for monitoring the geomechanical state of an array of coal mine workings is very promising, since the VODs developed on its basis have sufficiently high accuracy, measurement speed and good linearity of characteristics.