THE DEPTH EFFECT AS A SYSTEMATIC SOURCE OF ERROR IN COMPACTION TESTS

DER TIEFENEINFLUSS ALS SYSTEMATISCHE FEHLERQUELLE BEI VERDICHTUNGSPRUEFUNGEN

The variability of density in the vertical axis of the soil differs from the inconstancy in the horizontal direction by its classification. For the testing and evaluation of the density of a layer of soil these systematic variations of the stratum signify noteworthy sources of error. A description is given of the investigation of a trial area 50 M x 50 M formed of lightly cohesive sand subsoil of uniform character with EV2 between 450 and 650 KP/sq cm. The surface (gravely sand 0/32) was consolidated with a light tandem roller to a depth of 30 cm. The density tests, investigation details and their evaluation (21 trials) are recounted and show a significant influence of depth upon the compaction process. The degree of compaction of a gravel layer subjected to a vibrating apparatus increases so strongly with depth that the influence of depth in compaction control should not remain unnoticed. It increases in super lineal form. The variability of density is particularly pronounced in the upper 10 cm zone. The form of the trial hole (cylindrical or conical) has a marked influence. The question of the depth of the test has considerable significance. Values in the 9 to 20 cm deep zone below the surface can be several per cent less than the density of the total consolidated layer, therefore test results without reference to the depth are inappropriate for making a judgement. The major test error may be expected from the isotope apparatus measuring on the surface, since the values can originate from a depth of between 0 and 3 cm. /TRRL/

  • Corporate Authors:

    Strabag Bau-AG

    Siegburger Strasse 241
    Koeln 21,   Germany 
  • Authors:
    • Haas, Harald
    • John, E
  • Publication Date: 1977

Language

  • German

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00194102
  • Record Type: Publication
  • Source Agency: Bundesanstalt für Straßenwesen (BASt)
  • Files: ITRD, TRIS
  • Created Date: Jul 11 1979 12:00AM