The future of new cycling links – the Legi kamen tunnel

The thesis describes and analyses the construction of the Huda Luknja cycling link between Velenje and Mislinja, and more specifically the Legi Kamen tunnel, which is one of the facilities on the cycling link and the only tunnel that requires new construction. The main topics of the thesis are the excavation of the tunnel and the primary support of the Legi Kamen tunnel.

In the first part, I present the procedures for the start of work on the Legi Kamen tunnel project. First of all, it is necessary to select a professional and homogeneous working group with the necessary personnel for the smooth execution of the work. The planning team then draws up a time schedule and a financial plan for the work, which must be submitted to the client.

To facilitate the execution of the works plans for labor, materials, and machinery shall also be drawn up. All preparatory work must be carried out before the works start, the most extensive of which is the preparation and organization of the site with all the facilities, installations, and equipment. The site must be prepared in accordance with the Occupational Health and Safety Act and the Environmental Protection Act, and these laws must be complied with throughout construction.

In addition to the above, additional regulations and laws (Mining Act and Explosive Works Act) must be observed during the construction of the tunnel due to blasting. The Lega Stone Tunnel was built according to the new Austrian method of tunneling. In the following part of the thesis, I present this method in theory and with the example of the Legi Kamen tunnel. I describe in more detail the support types that were specified and used for the primary support of the tunnel and the materials needed for their construction.

In the last part of the thesis, I present the results of my research work, in which I compared the excavation of a tunnel by mining and a hypothetical excavation of a tunnel by mechanical bouncing. The results show that in order to determine the most economically appropriate method of work, it is necessary to carry out a cost and time analysis of the work.

The largest difference between the two methods of work in favor of the method with mining was in the hardest hill category, while the smallest difference was in the softest hill category.

I have also carried out an analysis of the steel consumption in the installation of the rod beams and compared them with the other types of steel arches used in mining. It turned out that we saved 65% of the steel that would have been consumed by installing conventional TH29 steel arches by using rod beams, thus providing a more economical and environmentally friendly method of working.