- Tunnel construction according to the New Austrian Tunneling Method
- Тunnel construction according to the Top - Down Method (Cut and Cover Method)
New Austrian Tunneling Method (NATM)
The essence of the “New Austrian Method” for tunnel construction is transforming the earth mass from an environment pressurizing the facility into a load bearing element part of it by using appropriate supports.
The tunnel is constructed by means of full face excavation but it can be executed in parts. The most important in this case is to cause the formation of a relieving arch in the mass which turns it into a load bearing element and replaces lining by installing deformable support – anchors, steel arches and shotcrete. The new stable equilibrium is identified by the subsiding radial deformations of the excavation measured on site.
The above method is used in masses with arbitrary strength when there is enough tunnel covering for the formation of a relieving arch and in tunnels with arbitrary dimensions of the cross section.
Top - Down Method (Cut and Cover Method)
Tunnel construction according to the Top - Down Method (Cut and Cover Method)
- Strained rope anchors for fortification of landslides, roads, anchoring of dam walls.
- Rope Anchors for fortification of landslides, deep underground excavations including pile construction, diaphragm walls and sheet retaining walls.
- Soil nails for fortification of underground excavations.
Drilling and grouting works
- Drilling and grouting works for construction of dam walls
- Consolidation of soils
- Grouting works