DEEP PLOUGHING

LAYERS OF LENSES OF FROST SUSCEPTIBLE CLAY/SILT ARE OFTEN FOUND IN ALLUVIAL (NON-FROST SUSCEPTIBLE) SAND DEPOSITS. AS THE LENSES OCCUR FREQUENTLY IN SMALL SIZES, IT IS NOT POSSIBLE TO LOCATE THEM DURING SOIL SURVEYS. PAVEMENT DESIGN SHOULD BE BASED ON THE PROPERTIES OF THE SAND (DESIGN THICKNESS APPROXIMATELY 0,5 M), NOT OF THE SILT (DESIGN THICKNESS APPROXIMATELY 1,0 M). DURING CONSTRUCTION VISIBLE LUMPS OF SILT/CLAY IN THE FORMATION LEVEL IN CUTS ARE REMOVED DOWN TO HALF A METER BELOW THE FORMATION LEVEL, AND SAND IN DEPTH IS BROUGHT IN. THE REMAINDER OF THE FORMATION LEVEL IS THEN PLOUGHED IN DEPTH IN HALF A METER THICKNESS, WHICH ENABLES THE LOCATION AND REMOVAL OF FROST SUSCEPTIBLE MATERIALS. THE PRICE OF PLOUGHING IS LOW (APPROXIMATELY 0,30 KR./M3). THE SAVINGS IN COSTS COMPARED TO THE COST OF DESIGNING THE PAVEMENT FOR INFERIOR-QUALITY FROST SUSCEPTIBLE MATERIALS ARE HIGH (100.000 KR. ON THE KILOMETER OF MOTORWAY, WHERE THE PRINCIPLE WAS INTRODUCED). THE TECHNIQUE OF DEEP PLOUGHING MAY BE USED TO BREAK UP STRATA UNDER THE FORMATION LEVEL, MAKING THE SUBSOIL MORE HOMOGENEOUS, THUS REDUCING THE NECESSARY THICKNESS OF THE PAVEMENT.

Media Info

  • Features: Figures; Photos;
  • Pagination: p. 181-4
  • Serial:
    • Dansk Vejtidsskrift
    • Volume: 49
    • Issue Number: 9
    • Publisher: Dansk Vejtidsskrift APS
    • ISSN: 0011-6548

Subject/Index Terms

Filing Info

  • Accession Number: 00238256
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: TRIS
  • Created Date: Apr 20 1974 12:00AM