A critical pressure test carried out on a hydraulic piezometer gives an indication of the total pressure in the soil surrounding the piezometer tip. To find out if this pressure corresponds to the minor or major principal stress, critical pressure tests have been made on 15 piezometers with their tips in groups of earth pressure cells in the clay cores of two dams. The tests were carried out during construction and repeated several times after construction when varying degrees of pore pressure dissipation had occurred. Major and minor principal stressed were calculated from earth pressures measured by the cells and it was found that when the effective stresses were low, the critical pressures were close to (sigma 1 + sigma 3)/2. When the effective stresses were greater, the critical pressures were less than (sigma 1 + sigma 3)/2, but were always greater than sigma 3.

  • Supplemental Notes:
    • Presented at the ASCE Specialty Conference on In-Situ Measurements of Soil Properties, North Carolina Univ., June 1975.
  • Corporate Authors:

    Building Research Establishment

    Building Research Station, Garston
    Watford WD2 7JR, Hertsford,   England 
  • Authors:
  • Publication Date: 1975

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 15 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00127198
  • Record Type: Publication
  • Report/Paper Numbers: CP 39/75
  • Files: ITRD, TRIS
  • Created Date: Dec 16 1975 12:00AM