Brief Probe Of The AE Activity During The Failure Process Of Rock During Uniaxial Compression

Rockburst is a kind of dynamically instable and geological disaster which threatens the safety of people and equipment. It is always a cosmopolitism tough problem and there is neither a set of mature theory in use of prediction it nor systematic and comprehensive understanding its reasons because of complicated problems existing in the rock-burst and different theories of grading. As accompanying phenomena, the AE Phenomenon of rock during the rock damage process points out many information of the process of rock failure, and paves a new way for forecasting crack initiation and extension. So it is important to study the AE phenomena for monitoring rock,rock failure and predicting earthquake. The analysis and study of AE signal of rock can infer its internal change and inversion the mechanism of rock failure. So we can study the damage mechanism of rock which has rockburst proneness during the load by using acoustic emission technique, and it is helpful to understand the rockburst proneness through analyzing the AE characteristics during the process of loading.Objective to explore the AE characteristics of different kinds of rock during uniaxial compression and the AE characteristics of rocks which have different rockburst proneness, we select each representative rock samples of volcanic rock,metamorphic rock and sedimentary rocks to act interior rock mechanics test. At the same time of uniaxial compression we collect the AE signal during the whole process then analyze the AE characteristics of different kinds of rock and calculation the rock impact energy index of rocks which can represent their rockburst proneness. Inquiring the relationship between rockburst proneness and their AE characteristics, then combine this relationship with the existing judgment methods to establish more objective and effective way to evaluate the rockburst proneness. The chief conclusion of the dissertation is in the following:(1)Dynamic failure duration under uniaxial compression are calculated, three rock burst tendentiousness are analyzed, obtains the rock burst proneness of granite is stronger than other two rocks, the rock burst proneness of sandstone is the weakest.(2)During the process of load to failure, the AE counts and counts to peak of the granite is more than other two kinds of rock. And the AE counts of the granite have an obvious change before the peak stress. The other two kinds of rock are steadier during the whole process.(3)During the process of "load-unload-reload", the AE counts and counts to peak of the granite is more than other two kinds of rock. And the AE counts of the granite has an obvious change at the peak stress, then experienced a great change until the failure of the rock.(4)AE b-value of three rocks is developing during the beginning of the load. During the whole process, AE b-value of marble and sandstone is steadier than granite, and AE b-value granite decline at the 50percent of the peak stress. AE b-value of granite is the largest and the sandstone is least.