BACKFILLING IN PUBLIC RIGHTS-OF-WAY - FINAL REPORT

THREE COMMONLY USED METHODS OF COMPACTING COHESIVE AND SEMI-COHESIVE TRENCH BACKFILL SOILS WERE EVALUATED UNDER FIELD CONDITIONS WITH MINIMUM TECHNICAL CONTROL. THE METHODS TESTED WERE THE MECHANICAL TAMPER, MOBILE TRENCH COMPACTOR AND JETTING. THE MECHANICAL TAMPER WAS FOUND TO BE RELATIVELY INEFFECTIVE IN NORMAL FIELD OPERATING CONDITIONS. THE MOBILE TRENCH COMPACTOR SHOWS MUCH PROMISE IN OBTAINING DENSITIES OF 95 PCF OR GREATER UNDER NORMAL FIELD OPERATING CONDITIONS. THE MOBILE TRENCH COMPACTOR SHOWS MUCH PROMISE IN OBTAINING DENSITIES OF 95 PCF OR GREATER UNDER THESE SAME CONDITIONS. THE JETTING METHOD WAS FOUND TO BE INEFFECTIVE AS A COMPACTION METHOD FOR COHESIVE-TYPE BACKFILLS. IT IS RECOMMENDED THAT THE USE OF MECHANICAL (HAND) TAMPERS BE RESTRICTED TO AREAS OUTSIDE THE LIMITS OF SIDEWALKS, PAVEMENTS AND LIGHTLY LOADED STRUCTURES. IN AREAS WHERE DRY DENSITIES OF 95 PCF OR GREATER ARE REQUIRED, THE COMPACTION OPERATIONS WITH MECHANICAL TAMPERS SHALL BE CAREFULLY CONTROLLED AND SUPERVISED. THE MOBILE TRENCH COMPACTOR WAS FOUND TO BE MUCH MORE EFFECTIVE THAN THE MECHANICAL TAMPER AND ITS USE IN COMPACTING COHESIVE TRENCH BACKFILLS UNDER SIDEWALKS, PAVEMENTS AND LIGHTLY LOADED STRUCTURES IS RECOMMENDED WHEN THE WEATHER AND MOISTURE CONTENT OF THE SOIL ARE SUITABLE FOR THE COMPACTION OF COHESIVE SOILS. WHERE WEATHER, AND THE SOIL MOISTURE CONTENT MAKE IT IMPRACTICABLE TO COMPACT COHESIVE SOILS, OR WHERE THE TRENCH WIDTH AND/OR DEPTH PREVENT THE USE OF THE MOBILE TRENCH COMPACTOR, IT MAY BE NECESSARY TO BACKFILL WITH SAND, CRUSHED ROCK OR SCREENINGS. THE RELATIVE COST OF ADEQUATELY COMPACTING COHESIVE TRENCH BACKFILLS WITH THE MOBILE TRENCH COMPACTOR UNDER PROPER WEATHER, SOIL MOISTURE AND TRENCH CONDITIONS IS APPROXIMATELY ONE-HALF TO TWO-THIRDS OF THE COST OF JETTED GRANULAR BACKFILLS. /AUTHOR/

  • Supplemental Notes:
    • pp 1-f3, 21 FIG, 9 TAB, 9 REF, 6 APP
  • Corporate Authors:

    American Society of Civil Engineers

    1801 Alexander Bell Drive
    Reston, VA  USA  20191-4400
  • Publication Date: 1968-4

Subject/Index Terms

Filing Info

  • Accession Number: 00214831
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 10 1994 12:00AM