Scientific paper ID 2623 : 2024/3

The significant seismic risk to which the transport infrastructure sites are exposed s the development of modern reliable procedures for defining the seismic impact and seismic microzoning, especially for responsible engineering facilities located in areas with a seismic coefficient of 0.15 and with an expected macroseismic intensity of VII – VIII degree. Most of the territory of Bulgaria is zoned with a seismic coefficient of 0.15, and roads and railways are located in such areas.

The report examines the impact of potential seismic sources that threaten the reliability of transition areas in the connection between bridges and the earth embankment, as the basis of railways and roads, as well as analyzing and defining seismic parameters in order to increase the seismic reliability of structures.

This is necessary given that seismic impacts are unpredictable in time, place and intensity and therefore cause large negative consequences also on elements and facilities of the transport infrastructure, which can lead to serious material damage and casualties, for example, in high-speed train traffic and the consequences of shifting the railway track and subsequent derailment and/or falling off a bridge.