THE INFLUENCE OF MACROPORES ON DEBRIS FLOW INITIATION

Soil structure affects the movement of water in hillslope soils and therefore exerts a strong influence on slope stability. A debris flow is analysed within the confines of an instrumented catchment on the South Island, New Zealand, in order to examine the influence of soil macropores on slope stability. Tensiometric and slope throughflow data for nearby slope areas show that vertical cracks conduct rainfall at rates well in excess of the mineral soil matrix conductivity. The presence of a well connected pipe system at the soil-bedrock interface distributes this water quickly downslope. Under exceptionally high rainfall intensities, however, this crackpipe system may induce slope instability by increasing the rate of infiltration over lateral pipeflow rates. This results in a build-up of pore pressure at the soil-rock interface and subsequent slope failure. (Author/TRRL)

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/04812085
• Corporate Authors:

  GEOLOGICAL SOCIETY

  BURLINGTON HOUSE, PICCADILLY
  LONDON,   United Kingdom  W1V 0JU
• Authors:
  • McDonnell, J J
• Publication Date: 1990

Language

• English

Media Info

• Features: References;
• Pagination: p. 325-331
• Serial:
  • QUARTERLY JOURNAL OF ENGINEERING GEOLOGY
  • Volume: 23
  • Issue Number: 4
  • Publisher: GEOLOGICAL SOCIETY
  • ISSN: 0481-2085

Subject/Index Terms

• TRT Terms: Failure; Flow; Hydrology; Porosity; Rainfall; Runoff; Slope stability; Soil structure; Soils
• Uncontrolled Terms: Flow rate
• Geographic Terms: New Zealand
• Old TRIS Terms: Soil porosity
• ITRD Terms: 5520: Failure; 5430: Flow (fluid); 4332: Hydrology; 6226: In situ; 8079: New Zealand; 5938: Porosity; 2507: Rain; 4329: Run off; 5783: Slope stability; 4156: Soil; 6255: Test; 4355: Water
• Subject Areas: Geotechnology; Highways; Hydraulics and Hydrology;

Filing Info

• Accession Number: 00617409
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Files: ITRD, TRIS
• Created Date: Nov 30 1991 12:00AM