Hydrogeological surveys for the preparation of the detailed design project documentation for the second track of the railway line Divača – Koper
Investment value: 850 mio €
Our role: Odgovorni projektant (hidrogeologija)
Year of the design of technical documentation: 2017 - 2020
10 deep exploratory boreholes were drilled on the Divača - Črni kal section as part of complementary investigations. Eight of them were equipped with piezometers and pressure probes were installed in them to take continuous measurements of the groundwater level. The additional boreholes and the accompanying investigations allowed us to finalise the forecast of the hydrogeological conditions in the tunnel route. In addition, monitoring has been used to determine the frequencies of occurrence of individual conditions and the rates of pressure rise, which is important for tunnel lining design. Complementary investigations have provided an improved picture of the piezometric height evolution in the tunnel route area. The results of the supplementary investigations have also allowed the definition of criteria for the final calculation of groundwater inflows/irruptions. The likelihood of inflows/irruptions is of particular importance from the point of view of construction and the design of appropriate protection measures during construction.