EVALUATION OF SELF-BORING PRESSUREMETER TESTS IN BOSTON BLUE CLAY

The research performed "undrained" self-boring pressuremeter tests (SBPT) at tow sites in a deep marine clay deposit of moderate sensitivity (Boston Blue clay) having a decreasing over consolidation ratio with depth. The program involved 2 tests with the French PAFSOR and 14 tests with the English CAMKOMETER devices. The initial pressure recorded after self-boring was generally much less than the in situ total horizontal stress, perhaps mainly due to improper installation techniques. However, the Marsland--Randolph graphical interation method yielded quite reasonable estimates of total horizontal stress, especially in the upper "stiff" clay, and this technique should be further evaluated via SBPT programs in other clay deposits. Values of undrained shear strength obtained from elastic-plastic and various derived methods of analysis were very sensitive to the input data, often showed considerable scatter and generally exceeded the in situ undrained shear strength appropriate for bearing capacity and stability analyses. In particular, derived peak strengths in the deep "soft" clay were too high by a factor of two or more. However, most of the tests did give reasonable estimates of undrained shear modulus. (FHWA)

  • Corporate Authors:

    Massachusetts Institute of Technology

    Department of Civil Engineering, 77 Massachusetts Avenue
    Cambridge, MA  United States  02139

    Urban Mass Transportation Administration

    400 7th Street, SW
    Washington, DC  United States  20590
  • Authors:
    • Ladd, C C
    • Germaine, JJT
    • Baligh, M M
    • Lacasse, S M
  • Publication Date: 1980-9

Media Info

  • Pagination: 239 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00325946
  • Record Type: Publication
  • Report/Paper Numbers: FHWA-RD-80-052 Intrm Rpt., FCP 35B2-501
  • Contract Numbers: DOT-FH-11-9264
  • Files: TRIS, USDOT
  • Created Date: Mar 12 1981 12:00AM