Hundreds of the builders and large amount of the specialized construction technology will continuously work at the site. The work activities will be demanding for coordination of individual stages like blasting operations, continuous drawing of the soil with subsequent concrete works in both tubes, the ascending with three lines (1670 m long) and the descending with two lines (1600m long). A temporary mobile mixing plant will be constructed in the close proximity to the site, which will facilitate otherwise every complicated transport of the amounts of the concrete needed.
The part of the tunnel, which is not in the sufficient depth will be concreted in an open pit and when finished, will be covered by soil. The rest of the route, approximately 1300 m, will be driven by a new Austrian tunneling method, which uses the bearing qualities of the rock massive to the maximum. The method allows optimizing the process of the tunneling and the securing of the stope, therefore lowers the construction costs. It is necessary to keep monitoring and evaluating the rock massive, while driving of the tunnel with explosives or the tunnel excavator, and that not only inside the tunnel, but also on the surface. The resulting data are used to adjust the speed of the drive and utilization of the safety measures.
It is traditional, that the tunnel is protected by St. Barbara, the Christian patron saint of the miners, gunners and those, working with explosives. A priest will consecrate her wooden statue and will say a prayer for successful accomplishment of the tunnel construction. The patron of the tunnel, the stand-in for St. Barbara for the duration of the construction, Ing. Marie Nádvorníková will be present at the event. The tunnel will be named in her honor – it will be called Marie.
The construction of the tunnel between Lochkov and Radotín started in June this year and its completion is planned to the end of year 2008. The following technology installation should take till October 2009.
Other technical data of the construction:
Excavated soil 310 000 m3
Construction concrete 90 000 m3
Concrete reinforcement 9 000 t
Volume of the explosive 200 t
Construction pit of the tunnels 230 000 m3
Subsequent backfill of the tunnels 130 000 m3
Stope area of the two line tube 100 m2
Stope area of the three line tube 136 m2