CLOSURE ON SPECIAL PROBLEMS IN SLOPE STABILITY

ONLY A FEW OF THE MANY SPECIAL PROBLEMS ENCOUNTERED IN PREDICTION OR INVESTIGATION OF SLOPE STABILITY WERE PRESENTED. SATYANARAYANA TOUCHES ON A VERY SPECIAL AND IMPORTANT PROBLEM IN SOIL MECHANICS, SWELLING OR EXPANSIVE SOILS. THE WRITERS DISCUSS EXPANSIVE SOILS WHICH VARY GREATLY IN ORIGIN AND COMPOSITION. SWELLING SOILS USUALLY ARE HIGHLY PLASTIC WITH HIGH ACTIVITY RATIOS AND EXHIBIT LARGE PORE-WATER TENSION OR SUCTION PRESSURES AND CONSEQUENTLY EXERT HIGH SWELLING PRESSURES DEPENDING ON THE WATER CONTENT AND LOAD. A COMPACTED, PARTIALLY SATURATED, AND SWELLING SOIL IN A FILL OR DAM MAY IN TIME BECOME FULLY SATURATED AND EXHIBIT CONSIDERABLE SWELLING. SOME REMEDIAL MEASURES ARE TO: (1) PLACE THE FILL AT MOISTURE CONTENTS WETTER THAN OPTIMUM, (2) PROTECT EXPOSED SURFACES IN FILLS AND ABUTMENTS AGAINST WETTING AND DRYING BY IMPERVIOUS BUT NONSWELLING SOILS OR BY OTHER MATERIALS AND (3) USE A SURCHARGE OF NONSWELLING SOILS TO REDUCE THE SWELLING. REFERENCE IS MADE TO DISCUSSION OF HEAVE AND SETTLEMENT OF SWELLING SOILS CONDUCTED IN A SYMPOSIUM AND A TEXAS CONFERENCE ON EXPANSIVE SOILS. CONSIDERING CURRENT KNOWLEDGE, IT IS VERY DIFFICULT TO DETERMINE THE RESIDUAL FACTOR OR THE STRENGTH PARAMETERS TO BE USED IN A STABILITY ANALYSIS OF SWELLING CLAYS AND CLAY SHALES. FIELD OBSERVATIONS ARE SUGGESTED WHICH MAY YIELD DATA FOR ESTIMATION OF THE RESIDUAL FACTOR OR THE STRENGTH PARAMETERS IN A POTENTIAL FAILURE SURFACE, BUT THESE OBSERVATIONS OR EXPERIMENTS ARE ADMITTEDLY DIFFICULT AND EXPENSIVE TO PERFORM. THE WRITERS FEEL THAT A COMPLETE UNDERSTANDING OF SWELLING OF SOILS DEPENDS ON ACCURATE FIELD SAMPLING FOR IN SITU MOISTURE AND DENSITY VALUES AND ON THE ABILITY TO PLACE GAGES IN THE IN SITU SOIL THAT WILL MEASURE NEGATIVE PRESSURES WITH CHANGES IN MOISTURE ACCURATELY. REFERENCES: SPECIAL PROBLEMS IN SLOPE STABILITY, W.J. TURNBULL, M.J. HVORSLEV, JOURNAL OF THE SOIL MECHANICS AND FOUNDATIONS DIVISION, PROCEEDINGS OF THE AMERICAN SOCIETY OF CIVIL ENGINEERS, PROCEEDINGS PAPER 52328, JULY 1967.

  • Supplemental Notes:
    • Vol 94, Sm6, PP1375-1378, 10 REF, APP
  • Corporate Authors:

    N/A

    ,   United States 
  • Authors:
    • Turnbull, W J
    • Hvorslev, M J
  • Publication Date: 0

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  • Accession Number: 00232598
  • Record Type: Publication
  • Report/Paper Numbers: No SM5, Proc Paper 490
  • Files: TRIS
  • Created Date: Aug 15 2004 2:44AM