ESTIMATING STANDARD DENSITIES FOR EMBANKMENT AND SUBGRADE SOILS

AN INVESTIGATION WAS MADE TO DEVELOP A RAPID AND RELIABLE METHOD FOR ESTIMATING THE OPTIMUM STANDARD SOIL DENSITY (AASHO METHOD T-99) FOR EMBANKMENT AND SUBGRADE SOILS ENCOUNTERED IN ALABAMA. A LITERATURE SURVEY WAS MADE TO SEEK OUT ANY RAPID METHODS FOR ESTIMATING DENSITY VALUES REPORTED BY OTHERS AND TO EVALUATE THE RELATIVE MERITS OF EACH BASED ON THE REPORTED INFORMATION. AS A RESULT OF THE PRELIMINARY INVESTIGATION, IT WAS DETERMINED THAT TYPICAL MOISTURE- DENSITY CURVES AND MOISTURE-PENETRATION RESISTANCE CURVES WOULD BE THE BEST METHOD TO MEET THE OBJECTIVES OF THE RESEARCH PROJECT, NAMELY TO PROVIDE HIGHWAY SOILS INSPECTORS WITH RAPID AND SUFFICIENTLY RELIABLE METHODS FOR ESTIMATING STANDARD SOIL DENSITIES WHEN TIME OR CIRCUMSTANCES PREVENTED A MORE DETAILED LABORATORY TEST. A DETAILED LABORATORY INVESTIGATION WAS MADE OF THE MECHANICAL PROPERTIES OF 85 SOIL SAMPLES CHOSEN TO REPRESENT THE TYPES OF SOIL COMMONLY OCCURING IN ALABAMA, AND A SET OF MOISTURE-DENSITY AND MOISTURE-PENETRATION RESISTANCE RELATIONSHIPS WERE DEVELOPED TO DESCRIBE THESE SOILS. A NOMOGRAPH USING ALABAMA HIGHWAY DEPARTMENT SOIL DENSITY DATA WAS DEVELOPED FOR DETERMINING MAXIMUM DRY DENSITY AND OPTIMUM MOISTURE FROM A ONE-POINT DENSITY TEST. BY THE USE OF THE METHODS DEVELOPED, IT IS POSSIBLE FOR A SOILS INSPECTOR IN THE FIELD TO DETERMINE THE APPROXIMATE STANDARD DENSITY OF EMBANKMENT OR SUBGRADE SOILS IN A MATTER OF MINUTES, WHEREAS TYPICAL PROCEDURES MAY REQUIRE AS MUCH AS AN HOUR OR MORE IN SOME CASES. THE METHODS DEVELOPED IN THIS REPORT ARE NOT INTENDED TO REPLACE THE STANDARD LABORATORY METHODS CURRENTLY BEING USED TO DETERMINE MAXIMUM DENSITY, BUT TO SIMPLY FURNISH FIELD INSPECTORS WITH A RAPID AND RELIABLE APPROXIMATION WHEN MORE EXACT INFORMATION IS NOT AVAILABLE AND JOB CONDITIONS WARRANT THE USE OF EXPEDIENT DENSITY CONTROL MEASURES. /AUTHOR/

Media Info

  • Pagination: 88 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00232772
  • Record Type: Publication
  • Report/Paper Numbers: HPR 43
  • Files: TRIS, USDOT, STATEDOT
  • Created Date: Jan 19 2003 12:00AM