DESIGN OF INSULATED FOUNDATION

The test areas and associated theoretical analysis is reported of twelve structures in which artificial insulation retards geothermal heat loss. Four of the structures were instrumented with thermocouples and settlement gages. One structure has been tested over a 2-year period and the other three over a 1-year period. A general method of design is described and examples are presented. Insulated foundations may be adopted for both heated and unheated structures. In the former type, the perimeter foundation is protected by a layer of insulation around the building. The width and thickness of the insulation strip may be determined from the freezing index of the area. In unheated structures a continuous insulation mat must be provided beneath the entire area of both floor and footings. The perimeter insulation strip must also be provided. Figures are preseated which illustrate conventional and insulated foundations for heated and unheated buildings, and details are given of the installation of insulated foundations. A computer program is described which was utilized to prepare design graphs for the proposed approach and to evaluate the effect of the most important parameters. The program provided a solution to the heat conduction problem that allowed for transient heat flow and included the effect of lates heat of fusion. The potential capability and limitations of the program are discussed. The thermal properties of various soils are considered and the thermal properties of selected materials are tabulated. The effects are reviewed of depth to bottom isothermal boundary, of soil type, latent heat of fusion, and dimensional effects. A 14-point design procedure and recommendation is presented together with illustrations and examples. The use of non-water absorbing insulation material (extruded polystyrene board, styrene bead-board, or concrete) also provides a water barrier and reduced thermal gradients below footings.

  • Corporate Authors:

    Royal Norwegian Council for Scientific & Ind Res

    Gaustadalleen 25
    Oslo 3,   Norway 
  • Authors:
    • Robinsky, E I
    • Bespflug, K E
  • Publication Date: 1974-5

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 23-35
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00261589
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Oct 22 1974 12:00AM