THE MEASUREMENT OF SMALL PERMEABILITIES IN THE LABORATORY

The author describes a new type of falling head permeameter which he has developed to overcome the shortcomings of the constant head and usual falling head permeameter when measuring the permeability of a homogeneous clay. The basic principle is the replacement of the capillary tube in the usual type by a pressure transducer. The method is described in detail. A modification of the usual falling head permeameter formula was found to be satisfactory because of the linear relationship between volumetric deformation and pressure for the transducer. Details are given of tests, namely the measurement of the permeability of a montmorillonite traxial sample and of a rubber membrane. In discussing the method, the author points out that the equipment is already available in most laboratories. He found that great care must be taken to saturate fully the sample under test. His main problems were in the various connections and valves and he describes the methods used to check leakage and to ensure that it does not occur at points where it could not be checked. He concludes that the device is quick and easy to use and that although it was mounted on a triaxial cell for his work it could also be used with an oedometer or a permeameter. /TRRL/

Media Info

  • Features: Figures; Tables;
  • Pagination: p. 454-458
  • Serial:
    • GEOTECHNIQUE
    • Volume: 23
    • Issue Number: 3
    • Publisher: Thomas Telford Limited
    • ISSN: 0016-8505

Subject/Index Terms

Filing Info

  • Accession Number: 00260948
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Oct 11 1974 12:00AM