Construction And Application Of On-line Roadway Mine Pressure Monitoring System Based On Fiber Bragg Grating Sensors

Mine pressure monitoring is a scientific mean to reveal mine pressure activities,and it's also an important technical measure to ensure safe and efficient production of coalmines.At present in our country,most of the mine pressure sensors used in the mine pressure monitoring system are mechanical or electric instruments,in which the transmission and communication of underground pressure signals depend on electric energy generally,which brings the hidden danger to the coal mine production.The mine pressure monitoring system based on optical fiber sensing technology can avoid these problems a lot.In this paper,based on optical fiber sensing principle,mine pressure and strata control theory and mine pressure monitoring technology,the layout of monitoring station and measuring point is optimized,and an accurate and economic roadway mine pressure monitoring scheme is put forward,also the functional requirements of the monitoring system are analyzed.And then we developed the monitoring software platform corresponding to the monitoring system requirements.We also developed the corresponding mine pressure sensors based on fiber Bragg grating,designed the system line laying method and grating allocation method.On this basis,a complete mine pressure on-line monitoring system based on fiber Bragg grating sensors is built and industrial test is carried out in coal mine.The monitoring data is obtained and the law of roadway mine pressure is analyzed.Field application shows that the monitoring system can meet the engineering requirements.The hardware system of mine pressure monitoring based on optical fiber sensing technology mainly includes mine fiber grating demodulator,transmission fiber cable and fiber Bragg grating mine pressure sensors.Fiber Bragg grating pressure sensors include roof separation indicator,borehole stress meter,fiber Bragg grating force measuring bolt and fiber Bragg grating bolt dynamometer,which can realize the perception and measurement of the roof separation,the stress of the roadway surrounding rock,the stress state of the anchor rod and the load of the anchor bolt.The measurement signal is transmitted to the fiber grating demodulator in the form of light waves and is demodulated into wavelength data,and the wavelength data is transferred to the software platform of the monitoring system for further processing to obtain the corresponding mine pressure monitoring data and monitoring chart.The monitoring software adopts the C/S architecture.The server program is developed as a Windows system service running on a server,the client program is a Windows form application that is installed on a coal mine office computer.The software development language adopts the C# programming language based on Microsoft.NET platform.It realizes the real-time monitoring of mine pressure data,data storage management,data analysis and early warning,comprehensive analysis of reports and other functions.The software platform is compatible with all kinds of mine pressure sensors based on fiber optic sensing technology.At the same time,the design of software system has strong expansibility for the change of mine pressure monitoring scheme and parameter variation.Finally,the on-line roadway mine pressure monitoring system based on Fiber Bragg Grating sensors has been applied industrially in NO.1 coalmine of Yangquan Coal Industry Coporation and has realized the monitoring of mine pressure in return air lane of 81303 working face,including surrounding rock stress,roof separation,anchor rod stress and anchor load,which has provided technical support for the coalmine's safe and efficient production.