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Fractal Analysis of the Progressive Failure of Shales and Stiff Clays Under Shear

  • Luis E. VallejoEmail author
  • Jairo M. Espitia
  • Bernardo Caicedo
Conference paper
Part of the Springer Series in Geomechanics and Geoengineering book series (SSGG)

Abstract

Shales and stiff clays when deformed under direct shear stress conditions develop narrow shear zones within which different sets of discontinuities or cracks are present. These cracks form in the shear zone in a progressive manner. In the first stage of deformation, a small set of unconnected cracks called Riedel shears form. In the second stage of deformation, a series of cracks called Thrust shears form. They connect with the Riedel shears. In the third stage of deformation, The Riedel and Thrust discontinuities interact, forming an undulating and rough failure surface. In this study, the fractal dimension concept from fractal theory is used to evaluate the progressive degree of cracking in the shear zone that causes the failure of shales and stiff clays forming part of natural slopes and earth dams. It was established that the intensity of cracking in the samples was reflected in the fractal dimension values. High levels of cracking were associated with high values of the fractal dimension.

Keywords

Fractal Dimension Shear Zone Direct Shear Failure Surface Direct Shear Test 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

References

  1. Hirata T (1989) Fractal dimension of fault systems in Japan. Pure appl Geophys 131:157–170CrossRefGoogle Scholar
  2. Hyslip JP, Vallejo LE (1997) Fractal analysis of the roughness and size distribution of granular materials. Eng Geol 48:231–244CrossRefGoogle Scholar
  3. Mandelbrot BB (1967) How long is the coast of Great Britain? statistical self-similarity and the fractal dimension. Science 156:636–638CrossRefGoogle Scholar
  4. Mandelbrot BB (1982) The Fractal Geometry of Nature. Freeman, San FranciscozbMATHGoogle Scholar
  5. Perfect E (1997) Fractal models for the fragmentation of rocks and soils: a review. Eng Geol 48:185–198CrossRefGoogle Scholar
  6. Skempton AW (1966) Some observations on tectonic shear zones. In: Procedings of the 1st International Congress on Rock Mechanics, Lisbon, vol. 1, pp. 329–335Google Scholar
  7. Vallejo LE (1982) Development of the shear zone structure in stiff clays. In: Procedings of the 4th international conference on numerical methods in geomechanics, Edmonton, Alberta, Canada, vol. 1, pp. 255–262Google Scholar
  8. Vallejo LE (1995) Fractal analysis of granular materials. Geotechnique 45:159–163CrossRefGoogle Scholar
  9. Vallejo LE (1996) Fractal analysis of the fabric changes in a consolidating clay. Eng Geol 43:281–290CrossRefGoogle Scholar
  10. Vallejo LE (2009) Fractal analysis of temperature induced cracking in clays and rocks. Geotechnique 59:283–286. doi: 10.1680/geot.2009.59.3.283 CrossRefGoogle Scholar

Copyright information

© Springer International Publishing AG 2017

Authors and Affiliations

  • Luis E. Vallejo
    • 1
    • 2
    • 3
    Email author
  • Jairo M. Espitia
    • 1
    • 2
    • 3
  • Bernardo Caicedo
    • 1
    • 2
    • 3
  1. 1.Department of Civil and Environmental EngineeringUniversity of PittsburghPittsburghUSA
  2. 2.Departmento de Ingenieria de MinasUniversidad Pedagogica y Tecnologica de ColombiaSogamosoColombia
  3. 3.Departamento de Ingeneria Civil y AmbientalUniversidad de los AndesBogotáColombia

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