SOIL SUCTION

PORESUG I JORDARTER

This study of the moisture equilibria in unsaturated inorganic soils briefly describes the structural features of inorganic soils and gives a review of the normal particle-size distribution and the mineralogical composition of Norwegian soils. In order to clarify the interactions of water with silicate surfaces the structure and properties of water are outlined. On the basis of the magnitude and nature of the bonds of water in soils four different types of bonding are distinguished: chemically bound water, adsorptionally bound water, capillary bound water and osmotically bound water. The retention of water in soils is expressed quantitatively in terms of the free energy of the soil water relative to the free energy of free pure water at the same temperature and pressure. For convenience, relative free energy is quoted as an equivalent suction. Five methods have been used in the laboratory to measure the suction/moisture content relation for the soils investigated. These five methods are: (1) suction plate, (2) pressure membrane, (3) osmosis, (4) sorption tests, (5) psychrometer. The relation is a function of the grading of the soil, the density, the compressibility and the mineral composition of the particles. Where ice and water are simultaneously present in soil, the extra phase (ice) suppresses one degree of freedom of the system. Instead of being almost independent variables, the suction and the temperature become related. In the last chapter this relation is discussed with regard to free energy. /TRRL/

  • Corporate Authors:

    Norges Tekniske Hogskole

    Institutt for Veg-Og Jernbanebygging
    7034 Trondheim-NTH,   Norway 
  • Authors:
    • Noss, P M
  • Publication Date: 1978-2

Language

  • Norwegian

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 208 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00184276
  • Record Type: Publication
  • Source Agency: Norwegian State Highway Laboratory
  • Report/Paper Numbers: Meddelese No. 14 Thesis
  • Files: ITRD, TRIS
  • Created Date: Jan 13 1979 12:00AM