Estimating Joint Normal and Shear Stiffness Coefficient Using Statistical Methods

Document Type : Research Article

Authors

1 Dept. of mining and metallurgy, Yazd university

2 Dept. of Mining and Metallurgy, Yazd University

Abstract

In analyzing stability of geo-mechanical structures, considering the strength parameters of intact rock and discontinuity is of paramount importance. In jointed rocks, instable conditions are controlled in multiple manners by coefficient of discontinuity strength. The compressive strength of joint surface, roughness coefficient, deformation modules of rock mass and normal and shear stiffness coefficient are among the most important influential parameters in the behavior of discontinuities that often is estimated by experimental and in-situ tests. Among these parameters, estimating joint normal and shear stiffness coefficient, is expensive because it needs in-situ tests and use of huge and costly equipment, and there is a high probability of experimental and human error in it. In this study it has been tried to calculate some of the parameters of intact rocks and discontinuities that seem relevant to discontinuity normal and shear stiffness coefficient by using quantitative values. Therefore, the present data were gathered from the results of various experimental and in-situ tests and then were studied. Statistical analysis of single and multivariable of this data indicated that there is a considerable relationship between normal and shear stiffness coefficient with intact rock and discontinuity parameters in a way that estimating normal and shear stiffness coefficient from other parameters became possible.

Keywords

Main Subjects


[1] Bandis, S.C., Lumsden, A.C., Barton, N.R., 1983. “Fundamentals of Rock Joint Deformation” international Journal of Rock Mechanics and Mining Sciences and Geo-mechanics, Abstract, 20(6): 249-268.
[2] Goodman, R.E., Taylor, R.L., Brekke, T.L., 1968. “A model for the mechanics of jointed rock” Journal of the Soil Mechanics and Foundations Division: proceedings of the American Society of Civil Engineers, 94(SM3): 637-659.
[3] lnfanti, N., Kanji, M.A., 1978. “In situ shear strength, normal and shear stiffness determinations at Agua Vermelha Project” Proceeding of 3rd International congress of IAEG, Madrid, Vol. 2, pp. 175-183.
[4] Kulhaway, F.H., 1978. “Geo-mechanical model for rock foundation settlement” Journal of the Geo-technical Division: Proceedings at American Society of Civil Engineers I 06(GT2): 21 L-227.
[5] Rosso, R.S., 1976. “A comparison of joint stiffness measurements in direct shear, triaxial compression and in situ”. International Journal of Rock Mechanics and Mining Sciences and Geo-mechanics, Abstracts, 13: 167-172
[6] John, K.W., 1970. “Civil engineering approach to evaluate strength and deformability of regularly jointed rock”. Proceeding of 11th Symposium on Rock Mechanics, pp. 68-82
[7] Barton, N.R., 1972. “A model study of rock-joint deformation” International Journal of Rock Mechanics and Mining Sciences, 9: 579-602
[8] Yazdani, M, Sharifzadeh, M, Kamrani, K. Ghorbani, M, 2012. “Displacement-based numerical back analysis for estimation of rock mass parameters in Siah Bisheh powerhouse cavern using continuum and discontinuum approach”, Tunnelling and Underground Space Technology 28 41–48
[9] Palassi, M., Asadollahi, P., “Tunnel Design Using Continuum and Discontinuum Approaches and the Effect of Joint Orientation on the Design”. 2007.
[10] Nutakor, D, Daemon, J, 2006, “Experimental determination of stiffness of joint in welded tuff” Final Technical report.
[11] Li, c, “Deformation modulus of jointed rock masses in three- dimensional space” Lulea University of Technology, SE-971 87 Lulea, Sweden
[12] Belytschko, T. Plesha, M. Dowding, C, H. 1984 “a computer method for stability analysis of caverns jointed rock” international journal for analytical and numerical methods in geo-mechanic, vol 8 473- 492.
[13] Vardakos, S, 2003, “Distinct Element Modeling of the Shimizu Tunnel No.3 in Japan” Virginia Polytechnic Institute and State University.
[14] Damjanac, B, 2008, “phase of long- term cavern stability” supporting technical report. Itasca consulting group, Inc.
[15] Perazzelli, p, Rotonda, T, 2009 “Stability Analysis of on active marble Quarry by DEM  Modelling” Proceedings of the International Conference on Rock Joints and Jointed Rock Masses, Tucson, Arizona, USA, January 7-8
[16] Flavio L, 2005, “Rock mechanics characterization of the rock mass” summary of primary data SKB
[17] Choi, S O, Chung, S, K. 2004. “Stability analysis of jointed rock slopes with the Barton-Bandis constitutive model in UDEC”. Int. J. Rock Mech. Min. Sci. Vol. 41, No. 3
[18] Fernando, T, 2008, “Numerical Analyses of the Hanging wall at the Kiirunavaara Mine” Licentiate Thesis.
[19] Wang,J,G, Ichikawa,Y, Leung,C,F, 2003 “A constitutive model for rock interfaces and joints”  International Journal of Rock Mechanics & Mining Sciences 40 (2003) 41–53
[20] Staub, I, Fredriksson, A, Outters, N, 2002“Strategy for a Rock Mechanics Site Descriptive Model” SKB
[21] Melin, H, 2012 “Controlling parameters for normal and shear behavior of rock fractures-a study of direct shear test data” SKB
[22] Hung, O, Coate, D F, 1998“Deformability of joints and its relation to rock foundation settlements” Can. Geo-tech. J. vol. 15