... failure criterion (Hoek et al. 2002). For nu- merical analysis, the PLAXIS program was used for tunnel stability for conditions both during and after construction, i.e. in operating conditions. Based on economic considerations and a appro- priate safety factor, the final lining was designed on the basis...

..., but the tunnels no longer fulfilled requirements for traffic space and safety. During winter the road was covered with ice from inflowing water, and the tunnel lining had deteriorated due to freeze-thaw effects. The true ground conditions did not reveal themselves prior to the reconstruction of the tunnels...