When underground sites are no longer needed, they have to be closed to ensure long-term safety and prevent any hazards to people or the environment.

Just as for the construction process, safeguarding typically requires individual solutions that are adapted to the specific local and geological side conditions.

The range of options extends from simple filling with debris all the way to highly complex sealing structures.

The optimal solution is selected according to the safeguarding objective.

The structures constructed for sealing drifts and shafts are executed according to the requirements as multi-stage systems that are gas-tight or impermeable and pressure-tight up to 110 bar.

Old mining sites near the surface for which fracture analysis is often not available are frequently the cause of surface subsidence that occurs in former mining districts.

These can sometimes pose an acute risk to public safety.

Skilled and often very rapid action is required here. Schachtbau Nordhausen stands for this as well.