| Learning from complexity - geomechanical back analysis of complex rock failures of the Brenner Base Tunnel Konrad Bergmeistser1; 1, Vienna, Austria; PAPER: 464/Geomechanics/Keynote (Oral) SCHEDULED: 18:15/Fri. 25 Oct. 2019/Athena (105/Mezz. F) ABSTRACT: With a total length of 64km, the Brenner Base Tunnel will be the world's longest tunnel. The northernmost construction lot, Tulfes-Pfons, comprises 41.5 km of tunnel. Conventional tunnelling methods were used for 26.5 km of this length, and an open gripper tunnel boring machine for the remaining 15 km. The area extends from the Innsbruck Quartz Phyllite zone to the Penninic Bündnerschiefer group. An open tunnel boring machine made it possible to investigate the rock mass in greater detail. Several fault zones and 10 large overbreaks in the different shapes and geotechnical rock mass behaviours were encountered in the first 13 km. One of them is presented more in detail in this contribution: the overbreak “San Francisco”, which was investigated with two-dimensional finite element back analyses which were including also the interaction effects with the ongoing advance of the main tunnels. The determination of the material parameters for the material laws for the rock mass and sprayed concrete is described and the finite element model including the concrete shells is explained. The calculations show that advanced material models are appropriate and loading/unloading effects can be successfully simulated. Purpose-built heavy steel segments, injected infill concrete and a cement/water suspension for binding the collapsed rock made it possible to bridge these cavities. Bergmeister, K.; Reinhold, C. (2017): Learning and optimization from the exploratory tunnel - Lernen und Optimieren vom Erkundungsstollen – Brenner Basistunnel. In: Geomechanics and Tunneling. Berlin, 05/2017 Österreichische Gesellschaft für Geomechanik, Ernst&Sohn, Berlin Bergmeister, K. (2011): Brenner Basistunnel – Der Tunnel kommt. Tappeinerverlag – Lana Bergmeister, K. (2012): Life Cycle Design for the world longest tunnel project. In: IAALCE (Editors: Strauss, Frangopol, Bergmeister), Vienna References: Bergmeister, K.; Reinhold, C. (2017): Learning and optimization from the exploratory tunnel - Lernen und Optimieren vom Erkundungsstollen – Brenner Basistunnel. In: Geomechanics and Tunneling. Berlin, 05/2017 Österreichische Gesellschaft für Geomechanik, Ernst&Sohn, Berlin Bergmeister, K. (2011): Brenner Basistunnel – Der Tunnel kommt. Tappeinerverlag – Lana Bergmeister, K. (2012): Life Cycle Design for the world longest tunnel project. In: IAALCE (Editors: Strauss, Frangopol, Bergmeister), Vienna |
