The principle is described of the Finnish Digital Terrain Model which has been developed for the comparison of different alignment and gradeline alternatives. In order to ensure that the use of DTM is as efficient as possible, a model process analysis of the road planning project has been prepared which contains the different phases of planning and construction. In a study of the swelling of soils from 5 different contsruction sites, the permanent swell was calculated (i.e. the ratio of in-situ unit weight to the unit weight to the unit weight in construction). The results revealed a distinct grouping according to different soils. Studies are reported which were planned to determine the angle of internal friction of stone materials. The effect of particle shape, angularity, density, percentage of fines and moisture content were also studied. Determination of the friction angle carried out in laboratory conditions show that the shape of the gradation curve has a noticeable effect on the friction angle, even within the relatively narrow area specified for the base course. Other factors of importance are density, particle shape and angularity, moisture content, and to some extent the percentage of fines. A survey was made to clarify the adequacy of lightweight aggregate as embankment fill under certain conditions. The importance is emphasized of knowing the unit weight of material, its behavior at the stage of embankment construction, variations in unit weight resulting from moisture in course of time, and the need of strengthening the upper part of the embankment or the required pavement thickness. Lightweight aggregate has proved a suitable material in many construction projects where it has provided adequate stability and prevented uneven settlement. Investigations are reported of 4 different insulation materials, concerning their ability to protect the subgrade from freezing, and their long-term behavior in operation.

  • 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:
    • Hakala, J
    • Eerola, M
    • Hailikari, T
    • Kankare, E
    • ORAMA, R
  • Publication Date: 1971

Media Info

  • Features: Figures; Tables;
  • Pagination: 31 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00265666
  • Record Type: Publication
  • Report/Paper Numbers: Book I-7
  • Files: TRIS
  • Created Date: Feb 27 1975 12:00AM