THE DESIGN OF PERMANENT CUTTING SLOPES IN STIFF FISSURED CLAYS

In the design of cutting slopes for permanent or 'long-term' stability in brown london clay and weathered upper lias clay, the following shear strength parameters can be used in association with the circular arc analysis: brown london clay c' = 1.5 kn/m squared, angle of shearing resistance referred to effective stress = 20 degrees; brecciated upper lias c' = 1.5 kn/m squared, angle of shearing resistance referred to effective stress = 23 degrees; fissured upper lias c' = 2 kn/m squared, angle of shearing resistance referred to effective stress = 25 degrees. These parameters apply to first-time slides. Provided that reasonably conservative values of the pore-pressure ratio are adopted the factor of safety can be 1.0 or marginally greater. Curves relating height to slope are presented, and comparisons made with nine long-term slips in brown london clay cuttings, and with eleven long-term slips in cuttings in the weathered upper lias. /TRRL/

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 457-466
  • Serial:
    • GEOTECHNIQUE
    • Volume: 24
    • Issue Number: 4
    • Publisher: Thomas Telford Limited
    • ISSN: 0016-8505

Subject/Index Terms

Filing Info

  • Accession Number: 00125134
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Nov 18 1975 12:00AM