Instituto Superior de Engenharia de Lisboa Departamento de Engenharia Civil Disciplina de InglêsTunneling ConstructionNew Austrian Tunneling Method - NATM Cristóvão Andrade Nº 38644
New Austrian Tunneling Method –NATMMethod Origin:• New Austrian Tunneling Method- Created betwen 1957 and 1965;• Austrian origin;• Developed by Muller, Rabcewicz and Pache.Propertys:• Tunnel auto-sustention;• Aplication of a shotcrete layer;• Monotorization of the tunnel state.
New Austrian Tunneling Method - NATMConstructive Method:- Creation of a first suport on the surface of the tunnelopening (loosenig zone) to avoid deterioration;- Opening of a tunnel traject not very long ;- Projection of concrete in all the circular perimetre of theexcaved zone (25 at 50 mm);- Introduction of metalics suports (cambots);- Fixation of the sustention reinforcement (usualy 6mm);- First hand of shotcrete, in a layer with thickness notsuperior at 150 mm;- Perfuration of the formed layer for the inserection of theanchorages;- Introduction of the suport for the next excavation cicle.
New Austrian Tunneling Method - NATM Legend Objective of the control Instrument 1 Deformation of the Convergence tape excavation surface. Surveying marks 2 Deformation of the Strainsters pavement of the tunnel envelope. 3 Monitorization of the Anchorage force pavemente suport, of the anchorage element. 4 Monitorization of the Embedments gauge pavimente suport referent Preasure Cells at concrete layer.
New Austrian Tunneling Method – NATMCase of Study – Frankfurt Subway• NATM method it was apllied at 55 - 70 % of the excavation process;• Joining the utilization of a tunneling machine roadheader to execute the process, it was possible spent 20% of the time of execution in relation at the use of any other kind of it;• This utilization alows get specifics operations of NATM method, like the terrains suport – in this case, it was not with shotcrete in the tunnel walls, but with the inserection of steel archs like temporarly suports.
New Austrian Tunneling Method - NATMBibliography/ Reference:• Tatiya, Ratan. “Civil excavations and tunneling: a pratical guide.”, Bristol, 2005.