ABSTRACT
The hydrogeological analysis and risk of karsts is of great significance in tunneling projects. The main objective of this study is to identify potential hydrogeological hazards that may affect the alignment of the Doroud-Khorramabad railway tunnels specifically tunnel No. 78 in Iran. The project has a length of 121 km, with 30 km tunnels that have been excavated using the new Austrian tunneling method (NATM). The prevalence of water-rich springs in the project area serves as a clear indicator of the advanced karst development. It is important to note that following periods of rainfall, there is a notable increase in water flow within the springs and tunnels, further highlighting the extent of karst development. Consequently, the level of karst hazards in this region is deemed to be particularly high, with the limestone rock formations within the project area identified as the primary geological hazard along the project.
