Comparative Assessment of Tectonic Waves affecting the Hydropower Plants in Făgăraş-Câmpulung Seismic Area

• Published in: Electrotehnica, Electronica, Automatica Vol. 69; no. 3; pp. 46 - 54
• Main Authors: Iosif, Lingvay, Victorin, Toader, Ovidiu, Ciogescu, Andrei, Mihai
• Format: Journal Article
• Language: English
• Published: Bucharest ICPE SA - Electra House of Publishing 01.07.2021
• Subjects: 21st century; Attenuation; Casualties; Dam safety; Data processing; Earthquake damage; Earthquakes; Hydroelectric dams; Hydroelectric plants; Hydroelectric power; Infrastructure; Morphology; Mountains; Nuclear energy; Nuclear power plants; Seismic hazard; Seismic waves; Tectonics; Romania
• DOI: 10.46904/eea.21.69.3.1108006
• ISSN: 1582-5175

In order to assess the seismic risk of the energy infrastructure on the Făgăraş-Câmpulung seismic area, the accelerations of seismic vibrations produced by 7 earthquakes were measured (in two distinct locations, with different morphostructural characteristics of the soil) and compared. Thus, were analysed 3 subcrustal earthquakes, with epicentres in Vrancea area, a crustal earthquake with epicentre in Făgăraş-Câmpulung seismic area (approximately 30 km from the measurement locations), 2 crustal earthquakes and a subcrustal earthquake with epicentres located at a longer distance (over 650 km) from the measurement locations. Following the data processing, it was found that the intensity of local vibrations produced by the analysed earthquakes is determined by the earthquake intensity, by the distance between epicentre and measurement point and by the geological layers morphological structure in the epicentre-measurement direction. The measurements showed that the mountains in the seismic waves direction, especially those generated by crustal earthquakes (with hypocentre h<10km), produce a significant attenuation of the measured vibrations. Based on measurement results and their analysis, it is considered that the energy infrastructure on the Făgăraş-Câmpulung seismic area presents an appreciable seismic risk. Thus, the earthquakes in the Făgăraş-Câmpulung seismic area can cause significant damage: the subcrustal earthquakes of Mw> 7.2 with epicentres in the Vrancea seismic area on large scale, and surface earthquakes, near the epicentre zone, on limited areas. Therefore, in order to ensure the safety of the hydroelectric dams, with high risk in operation, it is necessary to have them constructed and maintained so as to withstand vibrations with accelerations of at least 3.5-4 m/s2.