Study On Borehole Strain Monitoring System For Deep Mine Geological Exploration

The occurrence of coal mine geological disasters will pose a great threat to the safety of coal mine production and the life and property safety of production personnel,The prediction of coal mine geological disasters is particularly important.The occurrence of coal mine geological disasters is often accompanied by the sudden change of regional strain data,and there are a large number of geological exploration boreholes left over during geological exploration in the mining area,and most of them are located in coal seams hundreds to thousands of meters underground.By obtaining the strain data in the borehole,we can provide data support for possible geological disasters.For the monitoring of borehole strain data in coal mine geological exploration,the traditional electrical sensor can not adapt to the borehole environment in coal mine geological exploration because of its poor measurement stability,short transmission distance and poor measurement accuracy.Because of its many advantages,the continuous innovation and development of fiber Bragg grating sensing technology in recent years provides a new direction and idea to solve this problem.Under the above background,firstly,by studying the basic principle of FBG sensing technology and the requirements of geological exploration borehole strain monitoring,an embedded FBG strain sensor applied to geological exploration borehole environment is designed.The strain sensor adopts the temperature compensation method of double grating,and a limit ring is added on the basis of tubular packaging.The double grating compensation method can not only realize the temperature compensation of strain,but also measure the temperature parameters,and realize the double parameter measurement of strain and temperature.The installation of limit ring makes the sensor and concrete deform better,and improves the strain transfer coefficient of the sensor.Then,based on this sensor,the geological exploration borehole strain monitoring system is developed,and the hardware circuit design,communication protocol and software design of each module of the system are introduced in detail.The data acquisition task of the system is completed by FBG sensor and FBG sensor analyzer.Lora wireless communication technology is used to complete the long-distance data transmission task of the system.Considering the power supply problem in the field environment of geological exploration drilling,the power supply mode of solar panel connected with battery is used to supply power to the acquisition node of the system,The solar photovoltaic controller controls and optimizes the power supply module,and the upper computer designed by Lab View software and MySQL database will display the monitoring data of drilling in real time and give out limit alarm.Finally,the test results show that the FBG strain sensor has good strain sensing characteristics,has the function of temperature self compensation,and the upper computer software of the system has comprehensive functions.The development of the system lays a foundation for the function expansion and long-term utilization of coal mine geological exploration boreholes,and has important theoretical value and engineering significance for the monitoring and prediction of coal mine geological disasters.Figure [62] Table [10] Reference [66]...