A first step in the construction of the new side tunnel has been made: A first niche located in the main tunnel has recently been finished. It will be used for maneuvering vehicles and storing equipment that is needed for further construction and excavation activities.
It has been excavated by drilling and blasting and is 10 meters long and 3 meters wide. After a short excavation phase of three weeks, the floor was paved, and the ceiling was completed with a metal mesh to ensure safe operation in the new workspace. The construction now moves on to the next phase further down the main tunnel which will be the excavation of another niche. This niche will surround the entrance of the new side tunnel for which the excavation will start in 2024.
In parallel, the preparations for the PRECODE projects are running: They will focus on investigating the response of the rock mass to different excavation techniques comparing conventional to low impact operations. For this purpose, the rock mass surrounding the first 15 meters of the new side tunnel will be monitored before, during and after excavating.