Difficult terrain: Tunnelling projects in Bosnia along the A1
The A1 in Bosnia and Herzegovina is a motorway project that will link Budapest with Southern Dalmatia as part of the Pan-European Traffic Corridor Vc. The section leads through difficult topography, resulting in a need for a large number of bridges and tunnels.
On the section that leads from the town of Vlakovo west of Sarajevo south-west towards the town of Tarčin, DSI Austria supplied ground support products and injection foam resins for the following double tube tunnels:
- Tarčin Tunnel (400 m long)
- Suhodol Tunnel (2,800 m long)
- Grabosječ Tunnel (860 m long)
- Tulica Tunnel (340 m long)
- Gaj Tunnel (860 m long)
The tunnels were primarily excavated using the New Austrian Tunnelling Method (NATM). Self-Drilling Ø R32-250 and R51-550 DYWI® Drill Hollow Bar Anchors were installed for excavation pre-support. In addition, DSI supplied the Type 114 AT-Pipe Umbrella System for pre-support. The pipe umbrella pipes increase the stability in the working area by transferring loads in the longitudinal direction. In order to prevent the ingress of water and to consolidate loose rock in the tunnel working area, DSI Austria also supplied high quality DYWI® Inject Cement Injection Pumps with the necessary accessories.
DSI's products were completely and successfully installed until July 2014. The new road section has been opened to traffic by the end of 2014.