How much does the excavation project proceed in a day and what chemicals are used in blasting?
The excavation of the tunnel proceeds at most ten metres a day. The distance depends, in particular, on the type of bedrock. Certain work stages stop the process – sometimes for several days. No chemicals other than an emulsion explosive are used in the excavation project.
Do you take photos of buildings before blasting in case of any structural damage?
In areas where vibration-induced damage is possible (approximately 150 metres from the tunnel excavation), we inspect buildings before and after excavation. Any damage caused by excavation will be compensated. If you observe any damage to your building, please contact the contractor.
Does the excavation project reduce the quality of air? How extensive is its impact? Does the worksite cause damage to the air conditioning systems of buildings through dust?
Blasting fumes mainly consist of water vapour. Ventilating these fumes from the tunnels reduces the quality of air locally, mainly in the worksite area. The volume of street dust may increase along the vehicle route, mainly in the vicinity of access tunnels. The migration of fine particles from the worksite to the street area is reduced by cleaning vehicle tyres and the spreading of street dust is reduced by washing the streets. The air conditioning systems of buildings do not suffer any specific damage.