The Rogfast road tunnel with two tubes will be the deepest and longest undersea tunnel in the world with a total length of 26.7 km. Preliminary geological and geophysical investigations have shown that the Rogfast tunnel runs through an area of complicated geology with several thrust nappes and faults as well as many different types of rock.
The interpretation of the rock properties for low velocity zones in combination with the elasticity and bulk modulus completed the previous knowledge of the
geological situation during the excavation. Based on the gained knowledge, the TSP results supported the site management in estimating and selecting the quantity of grout and rock support types.