1.4 kilometres of core samples. 10 different locations. Drill holes down to 140 metres. All to ensure that one of Norway's largest metro projects is built on safe ground.
To ensure the durability of the tunnels at one of the largest infrastructure projects in Norway, a group of engineering geologists are currently working on core samples from sediments and rocks.
The project was won by COWI and Multiconsult last September and involves construction of a new metro line from Majorstuen in Oslo to the heart of Fornebu.
Laura Smids Arneson is one of the geologists currently working on 140 metres of new core samples. A full 1.4 kilometres of samples are to be analysed.
It's a time-consuming process. We open each box, look at the lithology and the geology, and study every single crack to see if it's a natural crack or a mechanical fracture. But everything is just an engineering challenge. You find out what you've got and you engineer around that.
COWI's analyses will reveal any cracks and anomalies that could cause water leaks and therefore require special safety measures. The result of the core logging forms the basis for the safety level in the tunnel. See video below for more details.