Abdalajis east railway tunnel (Spain) - double shield universal TBM cope with extremely poor and squeezing formations

For more than 30 years Double Shield TBMs were successfully utilised all around the world in a variety of geological formations. However, in some circumstances, Double Shield TBMs required the execution of by-pass tunnels and other special hand mining works to face special extremely poor conditions, and mainly: important and rapid squeezing phenomena, very unstable tunnel faces (flowing ground) and combinations of the two. To overcome these limitations, the new Double Shield Universal (DSU) TBM was designed and successfully tested in a first experimental application in the 18 km long Val Viola tunnel in the north of Italy. Following this first experimental application a DSU TBM has been specifically designed and manufactured for the 10 m diameter high speed railway tunnel of Abdalajis (Spain). This DSU TBM is characterized by extended facilities to treat the ground ahead of the face. In the first 2,5 km of tunnel, the encountered argillite formation was very unstable with rapid convergence of the tunnel walls and frequent face collapses. Large gas inflows with pressures up to 11 bars were measured in this section. In particular, for about 600 m at the contact with the adjacent limestone formation, the argillite rock was completely altered by the tectonic action and transformed into a kind of flowing gravel with very low friction angle and small cohesion. To advance the TBM under these conditions it was necessary to make large use of expanding foams to fill large voids in front and over the cutterhead. In addition, several patterns of chemically grouted micro-piles were executed from inside the TBM shield to improve the ground characteristics and stability ahead of the machine. Despite these extreme conditions and the restrictions to the tunnelling operations given by the gas presence, the TBM was able to advance without requiring any bypass or hand mining excavation and without the shields to get trapped. The article describes with details the technologies and the methods adopted to overcome these special geological conditions as well as the possible improvements to DSU technology that have been derived from the Abdalajis experience. (A) This paper was presented at Safety in the underground space - Proceedings of the ITA-AITES 2006 World Tunnel Congress and the 32nd ITA General Assembly, Seoul, Korea, 22-27 April 2006. For the covering abstract see ITRD E129148. "Reprinted with permission from Elsevier".

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/08867798
• Authors:
  • GRANDORI, R
• Publication Date: 2006-5

Language

• English

Media Info

• Pagination: p268
• Monograph Title: Rock chain 1: A set of codes for the studies of blocks instability inside a tunnel
• Serial:
  • Tunnelling and Underground Space Technology
  • Volume: 21
  • Issue Number: 3-4
  • Publisher: Elsevier
  • ISSN: 0886-7798
  • Serial URL: https://www.sciencedirect.com/journal/tunnelling-and-underground-space-technology

Subject/Index Terms

• TRT Terms: Design; Geology; Railroad tracks; Railroad transportation; Technology; Tunnels
• ITRD Terms: 9011: Design (overall design); 4053: Geology; 1173: Rail bound transport; 1062: Railway track; 3855: Technology; 3374: Tunnel
• Subject Areas: Bridges and other structures; Construction; Design; Geotechnology; Railroads; I54: Construction of Tunnels;

Filing Info

• Accession Number: 01032442
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: Sep 6 2006 1:49PM