DISCUSSION ON FROST HEAVING

MR. WATKINS DOES NOT FEEL THAT THE PAPER BY BENKELMAN AND OLMSTEAD OFFERS A COMPLETE EXPLANATION, SINCE THE PHENOMENA OBSERVED IN SOME FIVE OR SIX HUNDRED FROZEN SOIL CORES TAKEN FROM MINNESOTA SUBGRADES ARE NOT ENTIRELY EXPLAINED BY THIS THEORY. THERE SEEMS TO BE A DIFFERENCE IN THE SPACING AND THICKNESS OF THE ICE LAYERS IN THE DIFFERENT SOIL TEXTURES. A FIGURE WHICH SERVES TO EXPLAIN THE FORMATION OF THIN EVENLY SPACED ICE LAYERS IS PRESENTED. FIELD STUDIES INDICATE ICE, EXCEPT POSSIBLY HORIZONTAL ICE LAYERS, FORMS ONLY IN EXISTING VOIDS. THEREFORE, IT SEEMS THAT THE FORMATION OF THE HORIZONTAL VOID PLANES PRECEDES THE FORMATION OF THE ICE LAYERS. MR. TABER FEELS FROST HEAVING IS DUE TO THE GROWTH OF ICE CRYSTALS AND NOT TO CHANGE IN VOLUME. PRESURE IS DEVELOPED IN THE DIRECTION OF CRYSTAL GROWTH WHICH IS USUALLY DETERMINED CHIEFLY BY THE DIRECTION OF COOLING. EXCESSIVE HEAVING RESULTS WHEN WATER IS PULLED UP THROUGH THE SOIL TO BUILD UP LAYERS OR LENTICULAR MASSES OF SEGREGATED ICE THAT GROW IN THICKNESS BECAUSE WATER MOLECULES ARE PULLED INTO THE THIN FILM THAT SEPARATES THE GROWING COLUMNAR ICE CRYSTALS FROM THE UNDERLYING SOIL PARTICLES. AFTER REPEATED CYCLES OF FREEZING AND THAWING, IT WAS FOUND THAT PROMPT REFREEZING AFTER THAWING, RESULTED IN GREATER ICE SEGREGATION AND HEAVING THAN OCCURRED ON THE FIRST FREEZING. DIFFERENCES OF THESE RESULTS AS INTERPRETED BY BENKELMAN, OLMSTEAD, AND BURTON ARE DISCUSSED. THE AMOUNT OF ICE SEGREGATION AND FROST HEAVING IN SOILS IN CONTROLLED NOT ONLY BY PARTICLE SIZE, BUT ALSO BY OTHER FACTORS, SUCH AS SHAPE OF SOIL PARTICLES, COMPOSITION, AMOUNT OF WATER AVAILABLE, SIZE AND PERCENTAGE OF VOIDS, RATE OF COOLING AND MINIMUM TEMPERATURE, TENSILE STRENGTH, AND THE SURFACE LOAD OR RESISTANCE TO HEAVING. REPEATED CYCLES OF FREEZING AND THAWING INTRODUCED NO NEW FACTORS AND DO NOT ALTER THE MECHANICS OF FROST HEAVING. EXPERIMENTS SHOW THAT WITHIN CERTAIN LIMITS EXCESSIVE HEAVING TENDS TO INCREASE AS THE PARTICLE SIZE DECREASES, BUT THAT THE PRESENCE OF MUCH COLLOIDAL MATERIAL PREVENTS EXCESSIVE HEAVING BY REDUCING THE PERMEABILITY, EVEN THOUGH ICE SEGREGATION OCCURS.

  • Supplemental Notes:
    • Vol 11, Pt 1, PP 165-168, 173-177, 5 FIG
  • Authors:
    • Watkins, W I
  • Discussers:
    • Taber, S
  • Publication Date: 1932

Media Info

  • Monograph Title: Proceedings of the Eleventh Annual Meeting of the Highway Research Board Held at Washington, D.C. December 10-11, 1931. Part I: Reports of Research Committees and Papers
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00237903
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Jun 1 1971 12:00AM