复杂裂隙大理岩破坏声发射试验研究
(2 School of Civil Engineering and Mechanics，Shanghai JiaotongUniversity，Shanghai200240.China)
Abstract An experimental approach on the characters of acoustic emission (AE) of marble samples with pre-existing cracks under compression is carried out. The experiment shows that the pre-existing cracks are of significant influence on rock samples. Different acoustic emission characters indicate different failure mechanisms of rock samples with different cracks. For some rock samples, in which the failure is due to the initiation and propagation of tension mode wing cracks, a secondary peak value phenomenon of AE counts is observed. For thesamples with pre-existing Zigzag cracks, the failure mechanism is more complicated. In a fairly long time before collapse, acoustic emission is active, and the increasing amplitude of AE counts become larger with increase of load. As the sample whole collapses, AE number reaches a peak value and the accumulated AE counts of failure process occupies almost half of the summation of whole load processes. This reveals that the failure of materialswith pre-existing zigzag cracks is more unexpected and unpredictable. The zigzag cracks are of key influence on strength and stability of rock mass.
Key words acoustic emission, marble, wing crack, zigzag crack
