Optimization and Analysis of the Method to Determine Kaiser Point of the Method to Measurement to Stress by Acoustic Emission

The key of the study of acoustic emission measurement of in-situ stresses is to properly determine the Kaiser point. Through the simulation of core concrete in uniaxial compression failure process of acoustic emission test, the stress-strain curve,the relationships between stress, intensity and cumulant of acoustic emission with time of the specimens in the test process are obtained. The specimens are analyzed respectively with mutation point, maximum curvature method, double tangent method,again loading method (incomplete erasion phenomenon, two loading phase subtraction) various comprehensive judgement method and statistical analysis method of acoustic emission signal intensity. Understands the characteristics of Kaiser point of the specimens, summarizes and analyzes the methods to determine the Kaiser point and their adaptability, and was optimized. Research shows that the test can determine the sample physical properties,various methods can explain the phenomenon of Kaiser point from different angle, various comprehensive analysis will be more comprehensive to determine Kaiser point.