STP554: Reliability of Dilatometer Tests in the Determination of the Modulus of Deformation of a Jointed Rock Mass

    Singh, B
    Post doctoral research associate, University of Minnesota, Minneapolis, Minn.

    Pages: 21    Published: Jan 1974


    Abstract

    The available results from radial jacking and dilatometer tests are inadequate for the proper assessment and comparison of the reliability of these test procedures. In order to arrive at a rational evaluation of such tests, a computer program was devised to simulate a jointed rock mass, and sets of test data were then developed by performing (that is, mathematically simulating) a series of dilatometer tests at various locations within the rock mass. The computations indicate that dilatometer tests may provide a more reliable estimate of the mass modulus at a much lower cost than two or three radial jacking tests, provided that the orientation of both tests are the same. Curves are presented to facilitate estimation of the minimum number of tests required, in terms of average joint frequency and modulus reduction factor (MRF). Further, it is shown that the discrepancy between small and large scale tests may be due largely to the difference in orientation between tests and improper statistical inference there-from.

    Keywords:

    rocks, rock mechanics, boreholes, extensometers, joints (junctions), modulus of elasticity, mathematical models, stochastic processes, evaluation


    Paper ID: STP32143S

    Committee/Subcommittee: D18.12

    DOI: 10.1520/STP32143S


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