This article outlines the design and describes the construction of the Qinling Tunnel, the longest rail tunnel under construction in China. It is located on the north section of the Xian-Ankang railway. It has two roughly parallel 18.46km long tubes about 30m apart. It has a cover of 870m at the Xian portal on the north and 1025m at the Ankang portal in the south; its maximum depth below the mountains is about 1600m. The geology along the tunnel is mainly hard rock, consisting of gneisses and granites, with many rock bursts. The first tube is being excavated by two open-type tunnel boring machines (TBMs) and supported by primary shotcrete, bolts, and secondary cast-in-situ concrete, with a precast segment for the invert; its internal diameter is at least 7.7m. The second tube has a horseshoe-shaped cross section, and will be built by drill+blast and supported by primary shotcrete and bolts and secondary cast-in-situ concrete. The tubes are connected by cross passages at 420m intervals, and each of them has large safety chambers every 120m and small chambers at 60m in between. Construction of the pilot tunnel for the second tube began from both ends in January 1995, and was very rapid. Construction of the first tube began in December 1997, but has been slower than expected due to the very hard gneiss rock.

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  • Corporate Authors:

    Miller Freeman

    Calderwood Street
    London,   United Kingdom  SE18 6QH
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  • Publication Date: 1999-5


  • English

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  • Accession Number: 00768685
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Sep 10 1999 12:00AM