The Detection Study Of Stop Overlaying Rock Used By Fiber Bragg Grating Sensor

The root cause of the pressure caused by mining is the strata movement all appeared in ore mining. The overlaying strata movement exist multiple movement rules because of the nature strata with tectonic difference. Along with the increase of demand for coal in recent years, our new coal mine have more diversified overlying rock, there are more and more major disasters with mining pressure. So we should pay more attention to overlaying rock mobile mechanism research.The research methods of overlaying strata have mathematical and mechanics analysis method, Numerical analysis method, similar material model analysis method etc. Based on the research methods of similar material model is given priority to manufacture three modles witch rule for modleⅠ,Ⅱ,Ⅲ. The overburden strata movement conditions respectively are hard-rock overburden strata and the cycle fall down strata. The Fiber Bragg Grating is primary modles checking method.The method uses Fiber Bragg Grating sensor which embedded in modles. The strata movement will drive sensor changes deformation, so we can get the wavelength drift quantity of the sensor.The wavelength drift quantity of Fiber Bragg Grating sensor has the certain distinction by the different rock properties.So the changing rules of the wavelength drift quantity by the sensor can analyse the strata movement characteristics.There are two types Fiber Bragg Grating sensor which embedded in modleⅢ.The encapsulation materials of the sensor are stainless steel and acetate ethylene plastics. Take a group of representative detection data analysis of two sensor detection effected: the sensors deformation after by force is smaller when the encapsulation materials of the sensors have larger elastic modulus.Then the sensor has poor detection effect in the modle which is plastic. That provide a reference basis for developing the Fiber Bragg Grating sensor used by mining similarity models.