SENSITIVITY TO REMOULDING OF SOME VOLCANIC ASH SOILS IN NEW ZEALAND

Sensitivity to remoulding of some volcanic ash materials in New Zealand has been investigated. The subsoils studied were derived from airfall andesitic ashes containing a high proportion of allophane or from hydrothermally altered ashes containing mainly halloysite. These materials were characterised by large losses of strength on remoulding. Sensitivity values vary from 5 to 55 but do not directly relate to soil mineralogy or classification characteristics of the materials. Sensitivity is, however, associated with high undisturbed strength rather than with low remoulded strength. The study shows that only a small component of sensitivity may be attributed to thixotropy. Scanning electron micrographs of the most sensitive material showed imogolite fibrous linkage of allophane particles that were destroyed on remoulding and did not reform after long periods of resting. It is suggested that the irreversible breakdowns of electrostatic and physical bonds, existing between clay minerals, largely explains sensitivity in volcanic ash soils. (A)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00137952
• Corporate Authors:

  Elsevier

  Radarweg 29
  Amsterdam,   Netherlands  1043 NX
• Authors:
  • Jacquet, D
• Publication Date: 1990

Language

• English

Media Info

• Pagination: p. 1-25
• Serial:
  • ENGINEERING GEOLOGY
  • Volume: 28
  • Publisher: Elsevier
  • ISSN: 0013-7952

Subject/Index Terms

• TRT Terms: Ash content; Compressibility; Consolidation; Sensitivity; Soil stabilization; Soils; Strength of materials; Thixotropy; Volcanic rock; Volcanoes
• Geographic Terms: New Zealand
• ITRD Terms: 5905: Compressibility; 5791: Consolidation (soil); 4580: Fly ash; 8079: New Zealand; 5928: Sensitivity; 4156: Soil; 5544: Strength (mater); 5934: Thixotropy; 4002: Volcanic
• Subject Areas: Geotechnology;

Filing Info

• Accession Number: 00604142
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Files: ITRD, TRIS
• Created Date: Feb 28 1991 12:00AM