The article describes the triefus impression device designed to give a visual impression of the state of underground rock. The device, over 2 M long, is used in conjunction with nx boreholes (78 mm). It consists of an inner tube through which water or air passes to inflate a rubber tube. When a test is required, a thermoplastic film is wrapped around the device and is lowered down the borehole. The rubber tube is inflated to 75-100 psi forcing the film against the borehole walls so obtaining an impression of joint patterns, bedding planes, and fault zones. It may also be possible to distinguish between coarse and fine grained rock types. The device is descirbed as having application where the location of faults, joints, crushed seams, low strength zones or areas of high permeability is critical. (TRRL)

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  • Corporate Authors:

    Morgan-Grampian (Professional Press) Limited

    Morgan-Grampian House, Calderwood Street
    London SE18 6QH,   England 
  • Publication Date: 1980-12

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00334999
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD, TRIS
  • Created Date: Sep 16 1981 12:00AM