26 Damage Evaluation Inside the Concrete Dam …
323
Fig. 26.12 AE zone location
confirmed. A lots of AE occurred in zone 2 and zone 9, while in zones such as zone
4 and zone 5 almost no AE zone locations were detected. AE events appeared to
occur about 5 events per minute constantly. And no clear relationship was confirmed
between the short-term changes of the reservoir water level and the number of AE
zone location.
26.5 Conclusions
The feasibility of elastic wave tomography and surface wave tomography on concrete
dam was confirmed in this research. As a result, the depth distribution of the crack
was revealed by elastic wave tomography even if the propagation distance was long.
Also, the surface wave tomography revealed the depth distribution of the crack that
the crack was deeper in the western region.
In addition, it was confirmed that the sensor arranged in the inspection gallery
could measure AE activities inside the dam, which indicated the possibility of damage
monitoring of the concrete dam by AE analysis.
Acknowledgements This research is supported by the “Grant for R&D on River and Sabo Engineering Technologies” from the Ministry of Land, Infrastructure, Transport and Tourism (MLIT),
Japan.