Fluid pressure in coupled model
Fluid pressure in decoupled model
Perm eability in coupled model
Perm eability in decoupled modelNormalstressinjointplanedirection(MPa)Hydraulicconductivitycoe cient(m/0 5 10 15 20 25 30 35 40 45 50 s)− 4−3. 5− 3−2. 5− 2−1. 5− 1−0. 50Displacem ent from le side of A-A section (m)0E + 005E− 071E− 061.5E− 062E− 062.5E− 06Figure 19: Observed changes of normal stress in joint plane direction and hydraulic conductivity between coupled and decoupled models.50
45
40
35
30
25
20
15
10
5
0
0 5 10 15 20 25 30 35 40 45 50- 0205 × 10 −^5
× 10 −^6 - 5581 × 10 −^9
108642Figure 20: Darcy’s velocity magnitude (m/s).a plot of normal stress in joint plane direction and hydraulic
conductivity along the horizontal section A-A耠where푦=27
as is shown inFigure 16. The coupled and decoupled model
could be analyzed using Comsol Multiphysics code. In the
coupledcase,thegoverningequationsforsolidandfluid
phase are solved in weakly coupled sense. For the sake of
convenient contrast, the normal stress distribution as well as
hydraulic conductivity is plotted when no seepage-coupled
process is considered. The result shows that the normal
stress will be underestimated when no coupling of seepage
process is included. Moreover, the compressive stress leads to
thedecreaseofpermeability,andthehydraulicconductivity
increaseswhenseepageprocessisincluded.
4.6.2. Seepage Distribution.Flow velocity with the angle of
joint plane being 15∘is shown inFigure 20.Alltheprocess
is not considered time dependent. Therefore, the velocity
50
4540
35
30
25
20
15
10
5
0
0 5 10 15 20 25 30 35 40 45 502- 5
1- 5
0
0- 21 × 106
× 106
Figure 21: The seepage pressure distribution (Pa).101- 9
- 8
- 7
- 6
- 5
- 4
- 3
- 2
- 1
0
20 25 30
34
32
30
28
26
24
22
20
18
16Figure 22: Damage zone of the simulating model (the direction
of damage zone is approximately perpendicular to that of the joint
planes whose angle is 15∘).