Effects of statistical distribution of joint trace length on the stability of tunnel excavated in jointed rock mass

Document Type: Reply to comment on Paper

Authors

Department of Civil Engineering, Faculty of Engineering, Razi University, Kermanshah, Iran

Abstract

The rock masses in a construction site of underground cavern are generally not continuous, due to the presence of discontinuities, such as bedding, joints, faults, and fractures. The performance of an underground cavern is principally ruled by the mechanical behaviors of the discontinuities in the vicinity of the cavern. During underground excavation, many surrounding rock failures have close relationship with joints. The stability study on tunnel in jointed rock mass is of importance to rock engineering, especially tunneling and underground space development. In this study, using the probability density distribution functions of negative exponential, log-normal and normal, we investigated the effect of joint trace length on the stability parameters such as stress and displacement of tunnel constructed in rock mass using UDEC (Universal Distinct Element Code). It was obtained that normal distribution function of joint trace length is more critical on the stability of tunnel, and exponential distribution function has less effect on the tunnel stability compared to the two other distribution functions.

Keywords


[1] Jaeger J.C., Cook N.G.W (1979) Fundamentals of Rock Mechanics, third ed. Halsted Press, NY.
[2] Everling G (1964) Model Study of rock-joint deformation. Int J Rock Mech Min Sci & Geomech Abstr 1:319-326.
[3] Goodman RE, Heuz FE, Bureau GJ (1972) On modelling techniques for the study of tunnels in jointed rock. In: The 14th US Symposium on Rock Mechanics (USRMS). American Rock Mechanics Association, pp. 441–479.
[4] Jeon S, Kim J, Seo Y, Hong C (2004) Effect of a fault and weak plane on the stability of a tunnel in rock – a scaled model test and numerical analysis. International Journal of Rock Mechanics and Mining Sciences 41(1): 658-663.
[5] Yeung M, Leong L (1997) Effects of joint attributes on tunnel stability. International Journal of Rock Mechanics and Mining Sciences 34 (3):348. e341-348. e318.
[6] Hao Y, Azzam R (2005) The plastic zones and displacements around underground openings in rock masses containing a fault. Tunnelling and underground space technology 20 (1):49-61.
[7] Itasca Consulting Group, Inc. (2004) UDEC-Universal Distinct Element Code. User’s manual, version 4.0, Minneapolis.
[8] Jiang Y, Tanabashi Y, Li B, Xiao J (2006) Influence of geometrical distribution of rock joints on deformational behavior of underground opening. Tunnelling and underground space technology 21 (5): 485-491.
[9] Goodman RE, Shi G-h (1985) Block theory and its application to rock engineering. Prentice-Hall, Englewood Cliffs, NJ.
[10] Chan L-y, Goodman RE (1987) Predicting the number of dimensions of key blocks of an excavation using block theory and joint statistics. In: The 28th US Symposium on Rock Mechanics (USRMS). American Rock Mechanics Association, pp. 81– 87.
[11] Baecher G, Lanney N, Einstein H (1977) Statistical description of rock properties and sampling. In: The 18th US Symposium on Rock Mechanics (USRMS). American Rock Mechanics Association, pp. 1-8.
[12] Hoerger S, Young D (1990) Probabilistic prediction of keyblock occurrences. Rock mechanics; contributions and challenges:229-236.
[13] Song J-J, Lee C-I, Seto M (2001) Stability analysis of rock blocks around a tunnel using a statistical joint modeling technique. Tunnelling and underground space technology 16 (4): 341-351.
[14] Jia P, Tang C (2008) Numerical study on failure mechanism of tunnel in jointed rock mass. Tunnelling and Underground Space Technology 23 (5): 500-507.
[15] Wang X, Kulatilake P, Song W-d (2012) Stability investigations around a mine tunnel through three-dimensional discontinuum and continuum stress analyses. Tunnelling and Underground Space Technology 32: 98-112.
[16] Sari M, Karpuz C, Ayday C (2010) Estimating rock mass properties using Monte Carlo simulation: Ankara andesites. Computers & Geosciences 36 (7): 959-969.
[17] Park H, West T (2001) Development of a probabilistic approach for rock wedge failure. Engineering Geology 59 (3): 233-251.
[18] zadhesh J, jalali S-M.J, ramezanzadeh A (2013) Estimation of joint trace length probability distribution function in igneous, sedimentar y, and metamorphic rocks. In: Arab J Geosci.
[19] MathWave Technologies (2014) EasyFit -Data Analysis and Simulation. available from http://www.mathwave.com.