CAJ | 학술논문

采用极点对称模态分解方法对大理岩卸围压破坏的声发射数据进行去噪处理，分析大理岩卸围压变形破坏全过程的声发射变化特征。加载初期声发射振铃较小且增长缓慢，扩容点后声发射振铃计数率迅速增加。声发射时频变化呈现波动特征，峰值强度前频率出现突增，临近峰值强度时频率明显降低。利用关联维数方法计算大理岩卸围压破坏过程的声发射分形维数，声发射分形维数呈现阶段性变化，先增大后减小，在应力达到峰值强度的80%附近出现陡增，破坏时分形维数又出现大幅降低。频率变化特征与分形维的变化规律具有对应关系，声发射信号频率突然上升且分形维数陡增可认为是岩石破坏前兆。
채용겁점대칭모태분해방법대대리암사위압파배적성발사수거진행거조처리，분석대리암사위압변형파배전과정적성발사변화특정。가재초기성발사진령교소차증장완만，확용점후성발사진령계수솔신속증가。성발사시빈변화정현파동특정，봉치강도전빈솔출현돌증，림근봉치강도시빈솔명현강저。이용관련유수방법계산대리암사위압파배과정적성발사분형유수，성발사분형유수정현계단성변화，선증대후감소，재응력체도봉치강도적80%부근출현두증，파배시분형유수우출현대폭강저。빈솔변화특정여분형유적변화규률구유대응관계，성발사신호빈솔돌연상승차분형유수두증가인위시암석파배전조。
The extreme-point symmetric mode decomposition method was used to denoise the acoustic emission data of marble during unloading confining pressure failure process. The characteristics of acoustic emission were analyzed. Acoustic ringing counts rate level is small and grows slowly at the initial stage and increases rapidly after the expansion point. The acoustic emission frequency trends to fluctuate. It increases suddenly before peak strength and decreases significantly near the peak strength. The fractal dimension of acoustic emission was calculated by the method of correlation dimension algorithm. The fractal dimension of acoustic emission presents a phase change during marble during unloading confining pressure failure process. It increases at the initial stage and then decreases. The fractal dimension increases sharply when the axial stress reaches to 80% of the peak strength. It decreases significantly before the peak strength. There is relation between the frequency spectrum and the fractal dimension. The sudden rise of the acoustic emission frequency and the fractal dimension are failure precursor.