Because existing anchor end load testing instruments can not achieve long-term geotechnical engineering monitoring and long- distance data transmission, a novel FBG anchor dynamometer with simple mechanical structure and temperature selfcompensation suitable for engineering monitoring is proposed based on the axial strain characteristic of fiber Bragg grating. In order to improve strain transfer coefficient of this novel FBG sensor, its internal structure is analyzed by Solidworks 2012 finite element simulation software and further optimized based on axial strain distributions of this FBG anchor dynamometer. The relationship between center wavelength shift Δλ_B of pressure sensitivity FBG and external load F is calculated to be Δλ_B=9.4735·F theoretically. It is shown by performance experiment data that linearity of this sensor is larger than 0.99, its pressure measurement resolution is 0.093 kN and sensitivity coefficient K is 10.7 pm/kN. Coal mine tunnel pre-stressed anchor experiment data confirm that this sensor can achieve real-time surrounding rock pressure measurement, and that it well matches the measurement requirements under complex situation and has certain practical value.

fiber Bragg grating  /  anchor dynamometer  /  temperature self-compensation  /  mine tunnel experiment