PLANNING OF ROAD PROJECTS-EARTHWORKS-BULGARIA

The differences between the Proctor compaction methods in the laboratory and the methods adopted in Bulgaria are reported, as well as their consequences in maximum densities. The influence is considered of certain characteristics of compaction energy on maximum densities. With the same compaction energy, the normal Proctor method always gives maximum densities slightly higher than Bulgarian methods. The latter methods, however, give higher maximum densities with clays. On the basis of the analysis of meteorological data (from 29 observatories over a 30-year period), and the application of Prof. Loukinaof's method, the frost penetration of soils in the northern climatic zone is calculated to be 69 to 97 cm, and 24 to 74 cm in the southern climatic zone. An equation is presented which can be used to calculate the depth of frost penetration for an amount of frost equivalent to 100 to 600 degrees/day. Owing to the fact that the mass of the road has some thermic resistance, the depth of frost penetration is about 20-30 percent less than that found in natural ground. The minimum depths of road surfacing required for different roads (with different types of traffic) in different climatic zones are tabulated.

  • Supplemental Notes:
    • Presented at the XIVth World Road Congress, Prague, Czechoslovakia, 1971.
  • Corporate Authors:

    Permanent International Assoc of Road Congresses

    43 Avenue du President Wilson
    Paris 16eme,   France 
  • Authors:
    • Marchev, P N
    • Nicolor, A G
    • Paskov, P K
    • Todorow, C G
  • Publication Date: 1971

Media Info

  • Features: Figures; Tables;
  • Pagination: 21 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00265664
  • Record Type: Publication
  • Report/Paper Numbers: Book I-4
  • Files: TRIS
  • Created Date: Feb 27 1975 12:00AM