Numerical Analysis of Plate-Load Test Results on Fractured Rocks Using an Equivalent-Continuum Model: Case Study of the Bakhtiary Dam Site
Publication: International Journal of Geomechanics
Volume 15, Issue 1
Abstract
The plate-load test (PLT) is widely performed at large dam sites to determine the rock mass deformability. Analytical relations based on the theory of elasticity, as suggested by the International Society for Rock Mechanics and the American Society for Testing and Materials test standards, are commonly used to interpret the test results and calculate the rock mass deformation modulus. However, because of inconsistency of the test gallery geometry with the half-space medium assumption embedded in the analytical relations, a systematic error occurs in the calculation of the deformation modulus. Furthermore, when the tests are conducted on jointed rock masses, the test results show a considerable scatter, mainly due to the anisotropy of the deformability of jointed rock masses. In this paper, numerical modeling is used to interpret the results of a series of PLTs conducted at the Bakhtiary dam site in southwest Iran. An equivalent continuum model, called JointedRock, is used to back-calculate the stiffness of bedding planes from the test results. Finally, the equivalent continuum deformation moduli of the rock mass are determined numerically for various directions of loading relative to the orientation of major joint sets.
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Acknowledgments
The authors acknowledge the financial support of the Natural Sciences and Engineering Research Council of Canada. Thanks also go to the project manager of the Bakhtiary Dam and Hydroelectric Power Plant project for providing access to the test data.
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Published In
International Journal of Geomechanics
Volume 15 • Issue 1 • February 2015
Copyright
© 2014 American Society of Civil Engineers.
History
Received: Jun 11, 2013
Accepted: Apr 21, 2014
Published online: May 30, 2014
Published in print: Feb 1, 2015
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