“Södralänken” or the Southern Link, a 16.6 km of rock tunnels through the heart of Sweden’s capital city Stockholm, was the largest and most complex road tunnel system built in Sweden at the time.
The project was filled with highly complex passes with the tunnel at times passing literally 1 meter under high-rise buildings precision blasting had to be carried out, minimising simultaneous charge concentrations using hybrid ignition patterns. Charge concentration was continuously altered using a site law and regression analysis.
One of the technically most demanding passages was a 40-meter stretch of tunnel with negative rock cover. The clay above the tunnel was frozen giving it the same supporting qualities as rock, which made excavating and reinforcement possible in the area. A passage under a top secret communication tunnel also had its unique challenges, both because of its secrecy and the fact that our tunnel roof opened into the communication tunnel at a right angle. The most memorable challenge of the project was the first ever sawed and blasted shaft ever constructed.