Vol. 9 (2009 12 ), No. 03-091211 JASCOME CREEP ANALYSIS DISCONTINUOUS ROCK MASS AROUND UNDERGROUND CAVERN 1) 2) 3) Takakuni TATSUMI, Hidenori YOSHIDA and Masumi FUJIWARA 1) ( 761-0396 2217-20, E-mail: s08g407@stmail.eng.kagawa-u. ac.jp) 2) ( 761-0396 2217-20, E-mail: yoshida@eng.kagawa-u.ac.jp) 3) ( 730-0051 2-11-10, E-mail: m-fujihara@enecom.co.jp) The existence of a discontinuity in a rock mass cannot be disregarded when a longterm metamorphosis of the rock mass around an underground caven is discussed. The discontinuity can be opened, which increases the permeability of the rock mass. Foremore, the opening displacement of the discontinuity is increased by deviatoric stress condition. Thus, in this study, the analyses of long-term deformation in the discontinuous rock mass around the caven are conducted by the model which can consider the deformation of the discontinuity. In the result, it is found that the discontinuity is opened, but the deformation is converged. The proposed model is useful tool to analyse the long-term deformation of the discontinuous rock mass. Key Words : creep, cavern, discontinuity, discoutinuous rock mass 1. (1, 2) 300 m EDZExcavation Damaged Zone (1, 2) (3, 4) Maxwell (5, 6) (6) 2009 9 15 2009 11 12
2. 2.1. Carter (7) ε c = kσ n T p t q (1) ε c σ T t k n p q Norton-Bailey (8) Norton-Bailey ε c = qaσ n t q 1 = qa q 1 σ n q ε c q 1 q A = kt p = normaliry rule ε c ij { } ε c ij = ε c σ (3) σ ij (2) { σ = 1 (σxσ 2 y) 2 +(σ y σ z) 2 +(σ z σ x) 2 +6(τxy 2 + τyz 2 + τzx) } (4) 2 2 σ σ (8) 1 3 3 3 3 3 (6) 3 3 2.2. (5, 9, 10) (5, 9, 10) 2.3. (11, 12) (13) (13) (5,9,10) μ i (σn J <σy J ) μ = (μ i μ r) exp{ D(σn J σy J )} + μ r (5) (σn J σy J ) μ μ i μ r D σn J σy J 3. 3.1. 300m 300m 10 300m 0.5 2.0 2.0g/cm 3 300m 6 2 (6) (6)
10 10 Table 1 Analysis pattern of discontinuity 2.0 0.5 0.5 2.0 pattern pattern1 300m pattern2 y x disposal gallery pattern3 pattern4 Table 2 Width of open space of all analysis pattern Fig. 1 Concept of a cavern 300m 1600mm 600mm 128 503.5mm (5) 5 σ y =2.0 μ i =0.5 μ r =0.3 D =0.5 4 Table 1 Fig. 1 30 2 Fig. 1 3.2. 30 Fig. 2 Fig. 5 pattern1 Fig. 2 pattern3 Fig. 4 1 pattern2 Fig. 3 pattern4 Fig. 5 5 pattern2 pattern4 pattern1 pattern3 pattern pattern1 0.74 cm 4454.3 cm/s pattern2 0.16 cm 208.2 cm/s pattern3 0.58 cm 2736.3 cm/s pattern4 9 cm 65.9 cm/s pattern 0.5 pattern pattern Table 2 Fig. 2 Fig. 5 (6) 2 Hele-Shaw Table 2 20 ν =1.0 10 2 cm 2 /s 3 Table 2 300m
5.0 cm 5.0 cm Fig. 2 Deformed Shape (pattern1, 30 years later, scale fac- Fig. 4 Deformed Shape (pattern3, 30 years later, scale fac- tor:1) tor:1) 1.0 cm 1.0 cm Fig. 3 Deformed Shape (pattern2, 30 years later, scale fac- Fig. 5 Deformed Shape (pattern4, 30 years later, scale fac- tor:5) tor:5) Table 2 Fig. 6 Fig. 7 pattern1 Fig. 6 pattern3 Fig. 7 Fig. 8 pattern1 pattern3 pattern2 pattern4 Table 2 pattern1 pattern3 pattern2 pattern4 pattern1 1.5 cm 5000 14 pattern2 1600 0.4 cm pattern3 6000 1.3 cm patter4 2000 0.4 cm pattern Fig. 9 Fig. 12 pattern1 90 pattern2 pattern3 pattern4 60
Load 1 2.0 1.8 pattern1 pattern2 pattern3 pattern4 Confining Pressure 2.0 Confining Pressure 0.5 Shear Displacement (cm) 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 2000 4000 6000 8000 10000 12000 Time (day) Fig. 8 Time V.S. shear displacement Fig. 6 Stress condition (pattern1) Load 1 Confining Pressure 0.5 Confining Pressure 2.0 (14) Fig. 7 Stress condition (pattern3) 4. (1) 2 (1999) (2) TRU (2000) (3) Vol.103(1987) pp. 293-296 (4) Vol.109(1993) pp. 209-214
2 4 6 8 10 2 4 6 8 10 Fig. 9 Distribution of principal stress (pattern1, 30 years later, scale factor:1) Fig. 11 Distribution of principal stress (pattern3, 30 years later, scale factor:1) 2 4 6 8 10 2 4 6 8 10 Fig. 10 Distribution of principal stress (pattern2, 30 years later, scale factor:5) Fig. 12 Distribution of principal stress (pattern4, 30 years later, scale factor:5) (5) Vol.8(2008) pp. 31-36 (6) Vol.12(2009) pp. 255-264 (7) Carter, N.L. and Hansen, F.D. Creep of rock salt Tectonophysics Vol.92(1983) pp. 275-333 (8) (1985)pp. 59-65 (9) Vol.52A(2006) pp. 1-8 (10) Vol.51A(2005) pp. 51-58 (11) No.645/I II-50(2000) pp. 255-266 (12) No.680/ III-55(2001) pp. 245-261 (13) No.666/III-53(2000) pp. 145-158 (14) - - 49 5 (2008) pp. 266-276