PHYSICAL PROPERTIES OF SEATTLE SOILS

A STRESS-METER TESTING APPARATUS WAS DEVELOPED TO MEASURE PHYSICAL PROPERTIES OF TROUBLESOME SOILS ALONG THE SEATTLE FREEWAY. LATERAL STRESS COEFFICIENTS, SUBGRADE MODULI, AND PASSIVE FAILURE STRESSES WERE OBTAINED USING THE APPARATUS. HIGH-PRESSURE TRIAXIAL CELLS WERE DEVELOPED TO FIND PRECOMPRESSION STRESSES AND THE EFFECT OF LATERAL STRESS RELIEF ON STRENGTH PROPERTIES. PRECOMPRESSION PRESSURE FOR SEATTLE CLAYS WAS FOUND TO BE 375 PSI. NEUTRAL COEFFICIENTS OF EARTH PRESSURES FOR OVER-CONSOLIDATED SEATTLE SOILS WERE NOTED TO BE GREATER THAN UNITY AND TO INCREASE WITH SOILS INCREASING LIQUID LIMIT. AN EQUATION RELATING NEUTRAL COEFFICIENTS OF EARTH PRESSURES TO SOIL STRESS HISTORY AND SOIL PROPERTIES WAS PROPOSED. SUBGRADE REACTION MODULI WERE SHOWN TO INCREASE WITH INCREASING LIMIT OF SEATTLE CLAYS. NO DIRECT CORRELATION WAS FOUND BETWEEN PASSIVE FAILURE STRESS AND LIQUID LIMITS OF SEATTLE CLAYS, BUT AN AVERAGE VALUE WAS GIVEN FOR DESIGN PURPOSES. STRENGTH LOSS OF OVER- CONSOLIDATED SEATTLE CLAYS WAS ABOUT 23% DUE TO LATERAL STRESS RELIEF AND ABOUT 50% DUE TO CREEP. DESIGN STRENGTH OF ABOUT 27% OF THE SOILS INITIAL SHORT-TERM STRENGTH WAS RECOMMENDED FOR STABILITY CALCULATIONS OF UNRESTRAINED SLOPES.

  • Supplemental Notes:
    • Hpr-1/3/, UNIV GC-1530
  • Corporate Authors:

    Washington State Department of Highways

    Olympia, WA  United States 

    University of Washington, Seattle

    Seattle, WA  United States  98195
  • Authors:
    • Sherif, M A
  • Publication Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 00228615
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS, STATEDOT
  • Created Date: Aug 15 2004 2:08AM