LABORATORY TESTS ON A NEW BOREHOLE SEAL FOR PIEZOMETERS

When piezometers are placed in boreholes the borehole must be backfilled with a material as compressible and impervious as the original soil, which will form an effective seal against both the sides of the borehole and the connections from the piezometer tip. It is currently normal practice to use a grout for this purpose and this entails the use of machinery and pipework at the site of the borehole. Recently a simplified approach has been introduced by Soil Instruments Ltd. They have manufactured bentonite pellets which sink through water and swell to form a compressible clay of low permeability. This article describes tests to observe the behaviour of a borehole seal formed by these pellets and to measure its permeability. The seal was found comparable with one formed by grout and was made simply by pouring the pellets into a water-filled 'borehole' without any tamping or the need for any special machinery./Author/ /TRRL/

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00174653
• Corporate Authors:

  Foundation Publications Limited

  7 Ongar Road
  Brentwood CM15 9AU, Essex,   England 
• Authors:
  • Filho, P R
• Publication Date: 1976-1

Language

• English

Media Info

• Features: Figures; Photos; References;
• Pagination: p. 16-18
• Serial:
  • GROUND ENGINEERING
  • Volume: 9
  • Issue Number: 1
  • Publisher: EMAP CONSTRUCT LIMITED
  • ISSN: 0017-4653

Subject/Index Terms

• TRT Terms: Bentonite; Boreholes; Clay; Equipment; Grout; Laboratory tests; Permeability; Piezometers; Tests; Water
• ITRD Terms: 4186: Bentonite; 5711: Bore hole; 4177: Clay; 3674: Equipment; 5921: Permeability; 6107: Piezometer; 6255: Test; 4355: Water
• Subject Areas: Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00137742
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Files: ITRD, TRIS
• Created Date: Apr 13 1977 12:00AM