ELASTIC STIFFNESS AND STRESS CONCENTRATION IN CEMENTED GRANULAR MATERIAL

The normal stiffness and stress concentration in a cemented granular material were investigated by the finite element technique. The detrital grains were assumed to have a circular geometry, and they were bonded by cement layers of finite thickness. The normal stiffness of the partially cemented system was found to increase with the cement stiffness and the degree of cementation. For a system with relatively soft cement, the overall stiffness also increases with decreasing cement thickness. If the grain and cement have identical elastic properties, the overall stiffness seems to be independent of cement thickness and is a function of only the degree of cementation. The partially cemented system may be more stiff or compliant than a system of uncemented grains in Hertzian contact. Numerical results show that the cemented system is stiffer than the Hertzian system only if the areal percentage of cementation Acem is equal to or greater than 2.2%, if the elastic mismatch Ecem/Eg is equal to or greater than 0.3 and if the ratio of the minimum cement thickness to the grain radius ho/R is equal to or less than 1/9. Compared to the Hertzian system, the stiffness of a partially cemented system has a relatively low pressure dependence. Results show that the stress field is considerably more complex than what is assumed in the elastic foundation model. Appreciable shear stresses and lateral normal stresses can develop within the cement layer. Tensile stresses and very high compressive stresses may develop in the vicinity of the triple junction among grain, cement and pore space, with important implications for the micromechanics of failure in a cemented granular material. (A)

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    Elsevier

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    Kidlington, Oxford  United Kingdom  OX5 1GB
  • Authors:
    • ZANG, A
    • WONG, T-F
  • Publication Date: 1995-9

Language

  • English

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Filing Info

  • Accession Number: 00713431
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Nov 22 1995 12:00AM