10.6.6 Acoustic emission technique
The failure process of a rock slope is a transient phenomenon. Therefore, the rock slope undergoes fracture process irrespective to the duration of the deformation. During this process, elastic wave are generated in the rock. The acoustic emission (AE) monitoring technique detects such waves generated due to initiation, formation and growth and coalescence of cracks. The characteristics of acoustic wave signal can be analysed to evaluate the location of the acoustic events. Further the intensity of the acoustic emission, dominant frequency and other associated wave characteristics can be used to access the propensity of an impending slope failure.
This techniques segregation of useful signal and filter of noise signal along with proper installation of Acoustic emission sensor for a meaning full use of the system. Detection of acoustic emission signal is very difficult in soil material and characteristics of waves propagating is different from that in the rock. Therefore, the system requires considerable knowledge of wave characteristic in different mediums for reliable analysis