A better understanding of the cyclic fatigue phenomenon in rock could be helpful in the design of safe structures in rock and improving rock breaking methods. Specimens of Berea sandstone and Westerly granite were subjected to uniaxial and triaxial cyclic compression at a uniform loading rate of one cycle per second. Both the rock types weakened significantly under cyclic compression, the fatigue strength increasing with an increase of confining pressure. The accumulated permanent strain at the maximum stress level was found to be independent of the stress path and bounded by the complete stress-strain curve. Cyclic loading produces dilatancy and the onset of dilatancy is significantly reduced by repeated cycling. Photomicrography and acoustic emission monitoring indicate microfracturing as the principal mechanism of fatigue failure.

  • Supplemental Notes:
    • This article is an excerpt from the Proceedings of the Fourteenth Annual Engineering Geology and Soils Engineering Symposium that was sponsored by Idaho Transportation Department, Division of Highways; University of Idaho, Department of Geology and Department of Civil Engineering; Idaho State University, Department of Geology and Department of Engineering; and Boise State University, Department of Geology, and Department of Physical Science and Engineering. This symposium was held at the Rodeway Inn, Boise, Idaho, and was hosted by Boise State University.
  • Corporate Authors:

    Idaho Department of Highways

    P.O. Box 7129
    Boise, ID  United States  83707
  • Authors:
    • Rajaram, V
  • Publication Date: 1976-4-9

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Filing Info

  • Accession Number: 00142685
  • Record Type: Publication
  • Created Date: Feb 1 1977 12:00AM