Investigating the ground base and the causes for deformations of a building in the town of Russe, Bulgaria

The building was constructed in the central urban part on a collapsible loess of the II type. The later forms a slope with a height of 10–11 m in the structure proximity. Since the 1990s, the building has been subjected to deformations from strong earthquakes, subsidence and settlement caused by water supply and sewage over-moistening and suffusion flow of loess through the underground galleries beneath it. The present study makes a geotechnical assessment of the ground base, elucidates the causes for the resulting deformations, analyzes the data from the geotechnical monitoring since 2018 and discusses the effectiveness of the performed strengthening of the foundations and the ground base.