Length-diameter ratio of rock samples x variability m strength of rocks
DOI:
https://doi.org/10.14195/2184-8394_79_4Abstract
This paper deals with the height/diameter aspects of rock samples used in uniaxial compressive strength tests. It discusses the necessity to obey the lower limit (2,5) proposed by Intemational Society for Rock Mechanics, specially when weak weathered rocks are considered. It emphasises the intrinsic variability of rocks and states that this effect can be of greater significance than the strength changes imposed by a reduction ofthat ratio until a limit of2,0.
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AL CHALABI, M. e HUANG, C.L. - Stress distribution within circular cylinders in compression. Int. Journal Rock Mech.. Min. Sei. Vol. 11, pp. 45-56, 1974.
ABNT - ASSOCIAÇÃO BRASILEIRA DE NORMAS TÉCNICAS - NBR 7215 Cimento Portland - determinação da resistência à compressão. CB 18, 1991.
BARROSO, E.V. - Estudo das características geológicas e comportamento geotécnico de um perfil de intemperismo em leptinito. Tese de Mestrado, Instituto de Geociências da UFRJ, Rio de Janeiro, 1993.
BARROSO, E.V.; MARQUES, E.A.G.; CEZAR, G.S. e VARGAS Jr., E.A. - Caracterização fisica de gnaisses intemperizados do Município do Rio de Janeiro. Cong. Bras. Geol. Eng., 8, ABGE, pp. 49-60, Rio de Janeiro, 1996.
BIENIAWSKI, Z.T. - The effect of specimen size on compressive strength of coal. Int. Journal Rock Mech.. Min. Sei, Vol. 5, pp. 325-335, 1968.
BORDIA, S.K. - The effects of size and stress concentrations on the dilantancy and fracture of rock. Int. Journal Rock Mech. Sei. Vol. 8, pp. 629-640, 1971.
BRADY, B.T. - Effects of insert on the elastic behavior of cylindrical materiais loaded between rough end plates. Int. Journal of Rock Mech. Min Sei, Vol. 8, pp. 325-335, 1971.
DOBEREINER, L. - Engineering geology of weak sandstones London. Tese para Doutorado, Department of Geology - Imperial College of Science and Technology, 1984.
DOBEREINER, L. - Constructions problems related to excavations on soft rocks. Int. Cong. Soil Mech. Found. Eng., Relato Geral, Rio de Janeiro, 1989.
HAWKES, I e MELLOR, M. - Uniaxial testing in rock mechanics laboratories. Engineering Geology, Vol. 4, pp. 177-285, 1970.
ISRM - Suggested methods for determining the uniaxial compressive strength and deformability of rock materiais. International Society for Rock Mechanics - Committee on Laboratory Tests, 1978.
KOTTE, J.J.; BERCZES, Z.G.; GRAMBRG, J. e SELDENRATH, T.R. - Stress strain relations and breakage of cylindrical granitic specimens under uniaxial and triaxial loads. Int. Journal ofRock Mech. and Min. Sei., Vol. 6, pp. 581-595, 1969.
LUNDBORG, N - The strength size relation of granite. Int. Journal of Rock Mech. and Min. Sei., Vol. 4, pp. 269-272, 1967.
NUNES, A.L.L. - Um estudo sobre as características de resistência e deformabilidade de arenitos. Dissertação para Mestrado em Engenharia Civil - Pontificia Universidade Católica do Rio de Janeiro, 1989.
PELLS, P.J.N. e FERRY, M. J. - Needless stringency sample preparation standards for laboratory testing of weak rocks. Proc. Int. Cong. Rock Mechanics, 5, Melbourne Section a, pp. 203-207, 1983.
PENG, S.D. - Stress within elastic circular cylinders loaded uniaxially and triaxially. Int. Journal Rock Mech. Min Sei., Vol. 8, pp. 399-432, 1971.
PRESTES, A -Aspectos geológico-geotécnicos de um perfil de alteração de gnaisse facoidal. Dissertação para o Mestrado em Engenharia Civil - Pontificia Universidade Católica do Rio de Janeiro, 1993.
RODHE, J. e FENG, H - Analysis of the variability of unconfined compression tests of rock. Rock Mech.. & Rock Eng., No. 23, pp. 231-236.
SZLAVIN, J. - Relationships between some physical properties of rock determined by laboratory test. - Int. Journal of Rock Mech. and Min. Sciences & Geomech. Abstr., Vol. 11, pp. 57-66, 1974.
TSIDZI, K.E.N. - Compressive strength of foliated rocks. Proc. Symp. on Mechanics of Jointed and Faulted Rock, pp. 421-428, 1990.
TURK, N. e DEARMAN, W.R. -A correction equation on the injluence of length to diameter ratio on the uniaxial compressive strength of rocks. Engineering Geology, Vol. 22, pp. 293-300, 1986.
WIJSK, G. - The uniaxial strength of rock materiais. Geotechnical Testing Journal, Vol. 3, pp. 115-119, 1980.
