Elea iC (Slovenia)

Abstract The Karavanke tunnel is a double tube double lane motorway tunnel connecting Slovenia and Austria through the Karavanke massif with overburden up to 1100 m. On the Slovenian side, the tunnel runs through very diverse ground conditions, considering a 1 km long section in soft and highly deformable Permo‐Carboniferous claystones, siltstones, and sandstones (PC) under high overburden as the major challenge. Construction of both tunnel tubes in PC, the Western tube in 80 s and the Eastern tube recently, was characterized with large deformations up to 1.6 m and heavy damage of the primary lining requiring an extensive remediation of the initially installed lining, sometimes even several times. This article focuses solely on the Permo‐Carboniferous section and presents the construction of the Western tube, application of the lessons learned into the design of the Eastern tube, performance of the designed primary lining in the Eastern tube, development and application of an alternative excavation and support concept to cope with the extreme deformations, and remediation of the primary lining using solely fiber reinforced shotcrete (fibercrete).

Abstract Tunnelling differs fundamentally from mining, high rise buildings and civil surface construction in many ways, but when it comes to challenges, it combines the toughest from the three worlds. Tunnelling projects inherit uncertainties of ground conditions and constant preparedness for on‐site changes from mining; complexity, dynamics and the need for detailing from buildings; and one of the challenges that tunnels inherit from civil surface construction is definitely the complex and curved geometry. To overcome the challenges and exploit the benefits of BIM methodology on tunnelling project it is essential to harmonize particles of existing standards, guidelines, processes and tools from the three worlds.There are hundreds of specific questions arising from the BIM tunnelling pioneers: Which tool should be used? How can the efficiency of modelling and implementation of changes be increased? Which elements of the primary support structures need to be modelled? Which properties need to be assigned to elements? How to classify the elements? What to do when the performance of the software is over its limits? How should the spatial elements be used? How accurate should specific elements be modelled? And many more. Unfortunately, each of the question generates hundreds of different solutions. Thais article will tackle some of them and provide possible solutions as a result of experience from past projects with the goal of raising the discussion in a wider tunnel engineering society and consequently promoting the development and implementation of BIM methodology in tunnelling.