부산대학교 도서관

The processes of liquefaction of water-saturated soils under dynamic impacts are one of the many negative and destructive geological processes and phenomena that constitute the geological hazard in Bulgaria. Processes of liquefaction of water-saturated sediments on the territory of Bulgaria are registered during almost all strong earthquakes affecting its territory from both local and regional sources. Specific cases have been described by a number of authors. These processes lead to loss of bearing capacity of water-saturated sediments, deformations of the terrain, tilting, cracking and destruction of buildings and various facilities and can significantly increase the destructive effect of earthquakes. The article examines the terrains with historical cases of liquefaction of weak water-saturated soils on the territory of Bulgaria during strong earthquakes. The registered soil liquefactions are mainly in the Danube lowlands (Vidin, Kozloduy, Chernopol, Svishtov-Belene, Brashlyan); along the lower course of the Yantra River and around the town of Gorna Oryahovitsa; in the terrace of the river Golyama (town of Strazhitsa); in the terraces of the Iskar River (Sofia region); along the valley of the Struma River and the Maritsa River (between Chirpan and Plovdiv); in the sandstrips in the regions of Burgas and Varna; in coastal estuaries. The engineering geological assessment of this hazard requires knowledge of its origin, assessment of the potential occurrence of this phenomenon and the resulting risk. During this study, the conditions of the geological environment favorable for the occurrence of these phenomena (geological and geomorphological), the factors for their occurrence as well as methods for determining the conditions for liquefaction were analyzed. Different methods for assessing the tendency of water-saturated sands to liquefy are considered. Research on the dynamic properties of soils in Bulgaria is re-lated to the observed manifestations of these secondary seismogenic phenomena during strong earthquakes and in the design of important engineering facilities in the country. [ABSTRACT FROM AUTHOR]