Experimental and Numerical Simulations of Jointed Rock Block Strength under Uniaxial Loading
Publication: Journal of Engineering Mechanics
Volume 127, Issue 12
Abstract
To simulate brittle rocks, a mixture of sand, plaster of paris, and water was used as a model material. Thin galvanized sheets were used to create joints in blocks made out of the model material. To investigate the failure modes and strength, 30 × 12.5 × 8.6 cm jointed model material blocks having different joint geometry configurations were subjected to uniaxial compressive loading. Results indicated three failure modes: (1) tensile failure through intact material; (2) combined shear and tensile failure or only shear failure on joints; and (3) mixed failure of the above two modes depending on the joint geometry. The fracture tensor component in a certain direction quantifies the directional effect of the joint geometry, including number of fracture sets, fracture density, and probability distributions for size and orientation of these fracture sets. Results obtained from the experiments were used to develop a strongly nonlinear relation between the fracture tensor component and the jointed block strength. The laboratory experiments conducted on jointed model material blocks were simulated numerically using the Universal Distinct Element Code (UDEC). With careful selection of suitable material constitutive models for intact model material and model joints, and accurate estimation and calibration of mechanical parameters of the constitutive models through a combination of laboratory testing and numerical simulations of the intact model material and model joints separately, it was possible to obtain a good agreement between the laboratory experimental and distinct element numerical results.
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References
1.
Bieniawski, Z. T. ( 1968). “The effect of specimen size on compressive strength of coal.” Int. J. Rock Mech. Min. Sci. Geomech. Abstracts, 5(4), 321–335.
2.
Bieniawski, Z. T., and Van Heerden, W. L. ( 1975). “The significance of in-situ tests on large rock specimens.” Int. J. Rock Mech. Min. Sci. Geomech. Abstracts, 12(4), 101–103.
3.
Brown, E. T. (1970). “Strength of models of rock with intermittent joints.”J. Soil Mech. and Found. Div., ASCE, 96(6), 1935–1949.
4.
Chappel, B. A. ( 1974). “Load distribution and deformational response in discontinua.” Géotechnique, London, 24(4), 641–654.
5.
Cundall, P. A. ( 1988). “Formulation of a three-dimensional distinct element model—Part 1. A scheme to detect and represent contacts in a system composed of many polyhedral blocks.” Int. J. Rock Mech. Min. Sci. Geomech. Abstracts, 25(3), 107–116.
6.
Einstein, H. H., and Hirschfeld, R. C. (1973). “Model studies on mechanics of jointed rock.”J. Soil Mech. and Found. Div., ASCE, 99(3), 229–248.
7.
Goodman, R. E., Taylor, R. L., and Brekke, T. L. ( 1968). “A model for the mechanics of jointed rock.” Proc., ASCE, 94(3), 637–659.
8.
Hart, R., Cundall, P. A., and Lemos, J. ( 1988). “Formulation of three-dimensional distinct element model—Part II: Mechanical calculations for motion and interaction of a system composed of many polyhedral blocks.” Int. J. Rock Mech. Min. Sci. Geomech. Abstracts, 25(3), 117–126.
9.
Heuze, F. E. ( 1980). “Scale effects in the determination of rock mass strength and deformability.” Rock Mech. Rock Engrg., 12(3-4), 167–192.
10.
Hoek, E., and Brown, E. T. (1980). “Empirical strength criterion for rock masses.”J. Geotech. Engrg. Div., ASCE, 106(9), 1013–1035.
11.
Hoek, E., and Brown, E. T. ( 1997). “Practical estimates of rock mass strength.” Int. J. Rock Mech. Min. Sci. Geomech. Abstracts, 34(8), 1165–1186.
12.
John, K. W. ( 1970). “Civil engineering approach to evaluate strength and deformability of closely jointed rock. Rock mechanics—Theory and practice.” Proc., 11th Symp. on Rock Mech., American Institute of Mining, Metallurgical and Petroleum Engineering, New York, 69–80.
13.
Kulatilake, P. H. S. W. (1985). “Estimating elastic constants and strength of discontinuous rock.”J. Geotech. Engrg., ASCE, 111(7), 847–864.
14.
Kulatilake, P. H. S. W. ( 1998). “Software manual for FRACNTWK—A computer package to model discontinuity geometry in rock masses.” Tech. Rep., Submitted to Metropolitan Water District of Southern California, University of Arizona, Tucson, Ariz.
15.
Kulatilake, P. H. S. W., Ucpirti, H., and Stephanson, O. ( 1994). “Effect of finite size joints on the deformability of jointed rock at the two dimensional level.” Can. Geotech. J., Ottawa, 31(3), 364–374.
16.
Kulatilake, P. H. S. W., Wang, S., and Stephansson, O. ( 1993a). “Effect of finite size joints on the deformability of jointed rock in three dimensions.” Int. J. Rock Mech. Min. Sci. Geomech. Abstracts, 30(5), 479–501.
17.
Kulatilake, P. H. S. W., Wathugala, D. N., and Stephansson, O. ( 1993b). “Joint network modelling with a validation exercise in Stripa mine, Sweden.” Int. J. Rock Mech. Min. Sci. Geomech. Abstracts, 30(5), 502–526.
18.
Ladanyi, B., and Archambault, G. ( 1970). “Simulation of shear behavior of a jointed rock mass.” Proc., 11th Symp. on Rock Mech., American Institute of Mining, Metallurgical and Petroleum Engineers, New York, 105–125.
19.
Oda, M. ( 1982). “Fabric tensor for discontinuous geological materials.” Soils and Found., Tokyo, 22(4), 36–108.
20.
Pratt, H. R., Black, A. D., Brown, W. S., and Brace, W. F. ( 1972). “The effect of specimen size on the mechanical properties of unjointed diorite.” Int. J. Rock Mech. Min. Sci. Geomech. Abstracts, 9(4), 513–529.
21.
UDEC—Universal Distinct Element code, user's manual. (1996). Vol. 1–2, Itasca Consulting Group, Inc., Minneapolis.
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Received: Sep 6, 2000
Published online: Dec 1, 2001
Published in print: Dec 2001
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