FACTORS AFFECTING THE LONG TERM STRENGTH OF COMPACTED BEAUMONT CLAY. INTERIM REPORT

This report describes results of an ongoing study of the stability of embankments constructed of highly plastic clays in Texas. Previous studies showed that such embankments failed by sliding many (10-30) years after construction and that the apparent shear strengths were substantially lower that the long-term shear strengths determined on the basis of laboratory tests on compacted specimens. This report presents the finding of several series of tests performed to understand better the reasons for the discrepancies between field and laboratory shear strengths. Triaxial shear tests were performed to measure the effective stress shear strength parameters on (a) undisturbed specimens taken from actual slopes which had failed, (b) specimens prepared by consolidating soil from a slurry in the laboratory, and (c) specimens prepared by packing (remolding) soil into a special mold in the laboratory. In addition, residual shear strengths were determined on conventional compacted specimens. None of these tests fully explained the differences between field and laboratory strengths and produced agreement between laboratory and field values.

• Supplemental Notes:
  • Research study title: Development of Design Practice and Procedures for Determining Embankment Slope Stability.
• Corporate Authors:

  University of Texas, Austin

  Center for Transportation Research, 3208 Red River Street
  Austin, TX  United States  78705

  Texas State Department of Highways & Public Transportation

  Transportation Planning Division, P.O. Box 5051
  Austin, TX  United States  78763

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590
• Authors:
  • Green, R
  • Wright, S G
• Publication Date: 1986-10

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: 222 p.

Subject/Index Terms

• TRT Terms: Compacted clays; Effective stress; Embankments; Field tests; Laboratory tests; Residual shear strength; Shear strength; Stability (Mechanics); Time duration; Triaxial shear tests; Undisturbed samples
• Uncontrolled Terms: Long term
• Old TRIS Terms: Embankment stability
• Subject Areas: Geotechnology; Highways; I42: Soil Mechanics;

Filing Info

• Accession Number: 00472585
• Record Type: Publication
• Report/Paper Numbers: FHWA/TX-87/39+436-1, Res Rept 436-1, CTR 3-8-85-436-1
• Contract Numbers: 3-8-85-436
• Files: TRIS, USDOT, STATEDOT
• Created Date: Aug 31 1987 12:00AM