Test Study On The Abutment Pressure Of Working Face Based On Istributed Optical Fiber Sensor

After coal seam mining,the stress redistribution of the original rock in the coal-rock body,in order to form the mining dynamic stress field,the supporting pressure in the mine pressure appears leading role in various forms,it is usually the main power source of the complex dynamic disaster of the mine,which leads to the dynamic phenomena of the rockburst,the roof caving and so on,The monitoring of the support pressure and the stability control of the surrounding rock have become the key factors restricting the safe and efficient production of mine.The distributed optical fiber sensing technology has the characteristics of long sensing distance,multi-scale,high precision and good weather resistance,and it is helpful to achieve a large range of stress and strain testing,which is of great value to the monitoring of the support pressure.Taking the geological condition of Daliuta coal mine as prototype,combining with the mining conditions of 52306 working face and the mechanical parameters of surrounding rock mass,the paper calculates the support pressure of the bottom plate based on the theory of limit equilibrium,and lays the pressure sensor and the 705 silicone fiber sensor in the base plate of similar material physical model,The monitoring of the support pressure is realized by various methods,the pressure sensitivity coefficient is obtained by calibrating the encapsulated optical fiber sensor,which lays the foundation for the application of distributed optical fiber sensor in model test The test results of the pressure transducer and the optical fiber sensor are compared and analyzed.The experiment shows that the strain value of the fiber sensor with 705 silicone rubber package is linear with the package thickNess and load change,the fitting degree is more than 0.95,the relationship between the strain and package thickness and the load is 9.44??/(cm×kPa),which provides the basis for the test support pressure in the model experiment.By FLAC numerical simulation,the distribution regularity and characteristics of the support pressure around the stope are consistent with those of the pressure transducer,optical fiber sensor and theoretical analysis in physical model test.The research shows that the distributed fiber pressure sensor with 705 silicone rubber package can test the variation rule of the bearing pressure,and provide a new idea for the test of the model test stope support pressure.