Acoustic emission, fractal and chaos characters in rock stress-strain procedure

All characters of acoustic emission in the procedure of rock stress-strain have been studied experimentally. In initial consolidation and elastic phase, it is found out that hits seldom happens, energy keeps low, amplitude is small and no event is produced. In strain hardening phase, hits instantly increases, energy go up, amplitude enhanced and events happen. In strain softening phase hits decreased, energy became low, amplitude went back small and events happen. Due to the differences among acoustic emission characters in individual rock-transforming phases, acoustic emission method can be used to study micro-damage evolvement and predict macro-destabilization of engineering rockmass on spot. Based on research result of 3D damage localization in rock acoustic emission, the development of damages characterizes in fractal and statistic self-similarity. Besides, the event evolvement in rock acoustic emission can be described with chain growing model: activation-growth-activation. Through event number, the evolvement of tiny cracks in rocks is observed, and described it with Logistic equation logistic. Rock damage evolvement has furcation and chaos characters.