Detection and evaluation of AE waves due to rock deformation

In Japan, rock failure is one of the most frequent disasters as well as earthquakes. Because rock materials have brittle natures, deformation due to micro to macro fracture is normally of transient phenomenon. Acoustic emission (AE), detected as a premonitory phenomenon could be useful for prediction of eventual rock failure. In the paper, therefore, a prospective method to install AE sensors into the rock slope (WEAD) is developed. A series of studies on the WEAD are conducted to evaluate AE signals in the laboratory. Based on the experimental results, the criteria for classifying fracture states are proposed. Then, applying the criteria to the field data, fracture states estimated are compared with internal slope behavior evaluated from the displacement, borehole-strain, temperature and so forth. Thus, the applicability of the WEAD to evaluate rock stability is clearly demonstrated.