Employer: Ellatzite-Med AD

Designer and contractor: Geotechmin OOD

Project execution period: 2006 – 2008

Main data: Length – 2,100 m; cross section – 14 sq.m.; excavation volume – 3,000 cub.m.

Description of the project:

The drainage gallery is in process of building. The tunnel driving will be performed by a drill-and-blast method. Three drill drainage chambers will be constructed at the end of the gallery.

With a view to strengthen the rock massif, 10,000 friction anchors will be inserted during the driving process. In the massif areas with low weight-bearing capacity, 3-joint section steel frames – type BSP-28 (bell-shaped profile) – will be used. The drilling works will be done by means of direct controlled hydraulic tunneling and mining rig with one BUT. The loading and transportation of rock masses will be performed with a front loader and a dumper. There will be a water cleaning facility at the entrance of the gallery. The purified waters will be transported to Negarshtitza River.

The driving of the drainage gallery will finally solve the problem with the dewatering of “Ellatzite” copper mine valley for a period of 12 years.