ROCK-MASS BEHAVIOUR AT PUYMORENS

This article discusses the rock behaviour and geological conditions encountered during the construction of the Puymorens tunnel under the Pyrenees on the road between Barcelona, Spain and Toulouse, France. The 4.82km two-lane tunnel, with a cross-section of about 86sqm, was excavated from both sides by drill-and-blast, and is supported by shotcrete. A major face collapse occurred during drilling, as the actual rock-mass conditions were considerably different from the geological conditions predicted. The tunnel lies predominantly in Cambrian and Silurian slates, contacting gneisses and granite in the southern tunnel. The rock-mass has high deformability and squeezing plastic conditions. The article describes: (1) the geology and the Alpine-type tectonics of the area; (2) the collapse in the north drive; (3) construction aspects; (4) the contrast between forecast and actual conditions; and (5) the results of monitoring, especially long-term creep measurements. Under geological conditions of this type, it is essential to perform deep, representative exploration boring and calibrate seismic measurements. Rock mechanics tests and in situ stress measurements should be conducted to optimise stability calculations. Reflection seismics is recommended to improve detection of critical fault zones and other rock defects.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/09568700
• Corporate Authors:

  THE MINING JOURNAL LTD

  60 WORSHIP STREET
  LONDON,   United Kingdom  EC2A 2HD
• Authors:
  • SCHENK, V
• Publication Date: 1995-11

Language

• English

Media Info

• Features: References;
• Pagination: p. 345,347-8,350-2
• Serial:
  • WORLD TUNNELLING AND SUBSURFACE EXCAVATION
  • Volume: 8
  • Issue Number: 9
  • Publisher: THE MINING JOURNAL LTD
  • ISSN: 0956-8700

Subject/Index Terms

• TRT Terms: Construction management; Continuous structures; Creep; Detection and identification; Detectors; Drilling; Excavation; Excavations; Geology; Geomorphology; Measurement; Presplitting (Blasting); Seismicity; Shotcrete; Surveillance; Tunnels
• Geographic Terms: France; Spain
• ITRD Terms: 5188: Blasting; 3666: Construction method; 9006: Continuous; 4732: Creep (mater); 9115: Detection; 3871: Drilling; 5155: Excavation (process); 8036: France; 4053: Geology; 4055: Geomorphology; 6136: Measurement; 5731: Seismic; 4730: Shotcrete; 8105: Spain; 9101: Surveillance; 3374: Tunnel
• Subject Areas: Bridges and other structures; Construction; Geotechnology;

Filing Info

• Accession Number: 00720786
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD
• Created Date: May 24 1996 12:00AM