Code_Aster
®
Version
8.2
Titrate:
WTNV129 - Triaxial compression test not drained with the model of Hoek-Brown
Date:
04/05/06
Author (S):
C. CHAVANT, V. GERVAIS
Key
:
V7.31.129-A
Page:
1/8
Manual of Validation
V7.31 booklet: Thermo hydro-mechanical in porous environment of voluminal structures
HT-62/06/005/A
Organization (S):
EDF-R & D/AMA, CS-SI
Manual of Validation
V7.31 booklet: Thermo hydro-mechanical in porous environment of voluminal structures
Document: V7.31.129
WTNV129 - Triaxial compression test not drained with the model
of Hoek-Brown modified in total stresses
Summary
This test makes it possible to validate the elastoplastic law of behavior of Hoek-Brown modified in stresses
total is HOEK_BROWN_TOT with hydraulic coupling. It is about a triaxial compression test in not drained condition.
The aspect not drained is modelized by a null voluminal deformation of the skeleton and the hydraulic coupling
is taken into account. The sample is completely saturated, the incompressible skeleton and the fluid being supposed.
For reasons of symmetry, one is interested only in the eighth of a sample subjected to a triaxial compression test.
The level of containment applied is 5 MPa.
It is about a test of nonregression.
Modeling A is a modeling of the 3d_HM type with integration at the points of Gauss.
Modeling B is a modeling of the 3d_HMS type with integration at the points of Gauss or the nodes
(see Doc. [R7.01.10]).
Code_Aster
®
Version
8.2
Titrate:
WTNV129 - Triaxial compression test not drained with the model of Hoek-Brown
Date:
04/05/06
Author (S):
C. CHAVANT, V. GERVAIS
Key
:
V7.31.129-A
Page:
2/8
Manual of Validation
V7.31 booklet: Thermo hydro-mechanical in porous environment of voluminal structures
HT-62/06/005/A
Contents
1
Problem of reference .......................................................................................................................... 3
1.1
Geometry ........................................................................................................................................ 3
1.2
Properties of the material .................................................................................................................... 3
1.3
Initial conditions, with the limits and loading ............................................................................... 4
2
Modeling A ....................................................................................................................................... 5
2.1
Characteristics of modeling ................................................................................................ 5
2.2
Characteristics of the mesh ........................................................................................................... 5
2.3
Functionalities tested .................................................................................................................... 5
3
Results of modeling A .............................................................................................................. 6
3.1
Values tested ................................................................................................................................ 6
4
Modeling B ....................................................................................................................................... 7
4.1
Characteristics of modeling ................................................................................................ 7
4.2
Characteristics of the mesh ........................................................................................................... 7
4.3
Functionalities tested .................................................................................................................... 7
5
Results of modeling B .............................................................................................................. 8
5.1
Values tested ................................................................................................................................ 8
6
Summary of the results .......................................................................................................................... 8
Code_Aster
®
Version
8.2
Titrate:
WTNV129 - Triaxial compression test not drained with the model of Hoek-Brown
Date:
04/05/06
Author (S):
C. CHAVANT, V. GERVAIS
Key
:
V7.31.129-A
Page:
3/8
Manual of Validation
V7.31 booklet: Thermo hydro-mechanical in porous environment of voluminal structures
HT-62/06/005/A
1
Problem of reference
1.1 Geometry
One considers here a cube of dimension 1m
× 1m × 1m.
Co-ordinates of the points (in m):
WITH B C D
X 0 0.0.5 1
y 0 1.0.5 1
Z 0 0.0.5 1
1.2
Properties of material
Parameters of the elastic law of behavior:
E
= 4500 MPa
= 0.3
Parameters of the law of Hoek-Brown modified:
rup
= 0.005
LMBO
= 0.017
end
C
S
)
(
2
= 225 MPa
2
rup
C
S
)
(
2
= 482.5675 MPa
2
end
C
m
)
(
= 13.5 MPa
rup
C
m
)
(
= 83.75 MPa
= 3 MPa
rup
= 15°
LMBO
= 30°
= 3.3
X
Z
y
With
B
D
·
·
·
·
C
1 m
1 m
1 m
Code_Aster
®
Version
8.2
Titrate:
WTNV129 - Triaxial compression test not drained with the model of Hoek-Brown
Date:
04/05/06
Author (S):
C. CHAVANT, V. GERVAIS
Key
:
V7.31.129-A
Page:
4/8
Manual of Validation
V7.31 booklet: Thermo hydro-mechanical in porous environment of voluminal structures
HT-62/06/005/A
1.3 Conditions
initial,
with the limits and loading
The test breaks up into two phases:
1) Initially, one brings the sample in a homogeneous state
0
0
0
zz
yy
xx
=
=
. For
that, the corresponding confining pressure is imposed on the front faces (
1
=
X
),
side straight line (
1
=
y
) and higher (
1
=
Z
), the water pressures are taken null everywhere and
displacements are taken null on the faces postpones (
0
0
=
=
X
X
U
), side left
(
0
0
=
=
y
y
U
) and lower (
0
0
=
=
Z
Z
U
).
2) Once the homogeneous state obtained, displacements are maintained locked on the faces
rear, side left and lower. Hydraulic flows are null on all the faces. One
displacement is imposed on the higher face (
)
(T
U
Z
) in order to obtain a deformation
zz
equalize with 25% starting from the beginning of the second phase, by increments of deformation
constant
4
5
.
2
-
-
=
E
zz
. On the front faces and side straight line, one imposes conditions
with the limits in total stress:
MPa
N
5
0
-
=
=
.
Code_Aster
®
Version
8.2
Titrate:
WTNV129 - Triaxial compression test not drained with the model of Hoek-Brown
Date:
04/05/06
Author (S):
C. CHAVANT, V. GERVAIS
Key
:
V7.31.129-A
Page:
5/8
Manual of Validation
V7.31 booklet: Thermo hydro-mechanical in porous environment of voluminal structures
HT-62/06/005/A
2 Modeling
With
2.1
Characteristics of modeling
Modeling 3D
Cutting: 1m in height, 1m in width
Loading of phase 1:
MPa
5
-
0
0
0
=
=
=
zz
yy
xx
(confining pressure)
Boundary conditions:
0
0
0
0
=
=
=
=
=
=
Z
Z
y
y
X
X
U
U
U
Coefficient of Biot: 1
UN_SUR_K of water: 0 (coefficient of incompressibility of water)
Modeling: 3d_HM
2.2
Characteristics of the mesh
A number of nodes: 20
A number of meshs and types: 6 QUAD8 and 1 HEXA20
2.3 Functionalities
tested
Controls
DEFI_MATERIAU HOEK_BROWN
STAT_NON_LINE COMP_INCR RELATION
“KIT_THM”
“RELATION_KIT” =
“HOEK_BROWN_TOT”, “LIQU_SATU”, “HYDR_UTIL”
Code_Aster
®
Version
8.2
Titrate:
WTNV129 - Triaxial compression test not drained with the model of Hoek-Brown
Date:
04/05/06
Author (S):
C. CHAVANT, V. GERVAIS
Key
:
V7.31.129-A
Page:
6/8
Manual of Validation
V7.31 booklet: Thermo hydro-mechanical in porous environment of voluminal structures
HT-62/06/005/A
3
Results of modeling A
3.1 Values
tested
Localization Number
of command Forced
(MPa) Code_Aster
Not D
16
'
xx
1,14121
28
'
xx
1,94894
36
'
xx
1,49781
44
'
xx
- 2,69068
52
'
xx
- 1,24045 10
1
80
'
xx
- 3,72255 10
1
16
'
yy
1,14121
28
'
yy
1,94894
36
'
yy
1,49781
44
'
yy
- 2,69068
52
'
yy
- 1,24045 10
1
80
'
yy
- 3,72255 10
1
16
'
zz
- 1,74245 10
1
28
'
zz
- 2,23066 10
1
36
'
zz
- 2,6216810
1
44
'
zz
- 2,95247 10
1
52
'
zz
- 3,24666 10
1
80
'
zz
- 5,2947 10
1
16
Pressure
water
6,14121
44
Pressure
water
2,30931
80
Pressure water
- 3,2225 10
1
Code_Aster
®
Version
8.2
Titrate:
WTNV129 - Triaxial compression test not drained with the model of Hoek-Brown
Date:
04/05/06
Author (S):
C. CHAVANT, V. GERVAIS
Key
:
V7.31.129-A
Page:
7/8
Manual of Validation
V7.31 booklet: Thermo hydro-mechanical in porous environment of voluminal structures
HT-62/06/005/A
4 Modeling
B
4.1
Characteristics of modeling
Modeling 3D
Cutting: 1m in height, 1m in width
Loading of phase 1:
MPa
5
-
0
0
0
=
=
=
zz
yy
xx
(confining pressure)
Boundary conditions:
0
0
0
0
=
=
=
=
=
=
Z
Z
y
y
X
X
U
U
U
Coefficient of Biot: 1
UN_SUR_K of water: 0 (coefficient of incompressibility of water)
Modeling: 3d_HMS
4.2
Characteristics of the mesh
A number of nodes: 20
A number of meshs and types: 6 QUAD8 and 1 HEXA20
4.3 Functionalities
tested
Controls
DEFI_MATERIAU HOEK_BROWN
STAT_NON_LINE COMP_INCR RELATION
“KIT_THM”
“RELATION_KIT” =
“HOEK_BROWN_TOT”, “LIQU_SATU”, “HYDR_UTIL”
Code_Aster
®
Version
8.2
Titrate:
WTNV129 - Triaxial compression test not drained with the model of Hoek-Brown
Date:
04/05/06
Author (S):
C. CHAVANT, V. GERVAIS
Key
:
V7.31.129-A
Page:
8/8
Manual of Validation
V7.31 booklet: Thermo hydro-mechanical in porous environment of voluminal structures
HT-62/06/005/A
5
Results of modeling B
5.1 Values
tested
Localization Number
of command Forced
(MPa) Code_Aster
Not D
16
'
xx
1,14121
28
'
xx
1,94894
36
'
xx
1,49781
44
'
xx
- 2,69068
52
'
xx
- 1,24045 10
1
80
'
xx
- 3,72255 10
1
16
'
yy
1,14121
28
'
yy
1,94894
36
'
yy
1,49781
44
'
yy
- 2,69068
52
'
yy
- 1,24045 10
1
80
'
yy
- 3,72255 10
1
16
'
zz
- 1,74245 10
1
28
'
zz
- 2,23066 10
1
36
'
zz
- 2,62168 10
1
44
'
zz
- 2,95247 10
1
52
'
zz
- 3,24666 10
1
80
'
zz
- 5,2947 10
1
16
Pressure
water
6,14121
44
Pressure
water
2,30931
80
Pressure water
- 3,2225 10
1
6
Summary of the results
This case test is a test of not-regression developed to validate the model of Hoek-Brown modified in
total stresses, HOEK_BROWN_TOT with hydraulic coupling.
One finds the same results with two modelings 3d_HM and 3d_HMS.