Code_Aster
®
Version
8.3
Titrate:
WTNV128 - Triaxial compression test not drained with the model of Hoek-Brown
Date:
04/05/06
Author (S):
C. CHAVANT, V. GERVAIS
Key
:
V7.31.128-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: V7.31.128
WTNV128 - Triaxial compression test not drained with the model
of Hoek-Brown modified in effective stresses
Summary
This test makes it possible to validate the elastoplastic law of behavior of Hoek-Brown modified in stresses
effective, that is to say HOEK_BROWN_EFF with hydraulic coupling. It is about a triaxial compression test in condition not
drained. The aspect not drained is modelized by a null voluminal deformation of the skeleton and the coupling
hydraulics is taken into account. The sample is completely saturated, the skeleton and the fluid being supposed
incompressible.
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
8.3
Titrate:
WTNV128 - Triaxial compression test not drained with the model of Hoek-Brown
Date:
04/05/06
Author (S):
C. CHAVANT, V. GERVAIS
Key
:
V7.31.128-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
8.3
Titrate:
WTNV128 - Triaxial compression test not drained with the model of Hoek-Brown
Date:
04/05/06
Author (S):
C. CHAVANT, V. GERVAIS
Key
:
V7.31.128-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
8.3
Titrate:
WTNV128 - Triaxial compression test not drained with the model of Hoek-Brown
Date:
04/05/06
Author (S):
C. CHAVANT, V. GERVAIS
Key
:
V7.31.128-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
8.3
Titrate:
WTNV128 - Triaxial compression test not drained with the model of Hoek-Brown
Date:
04/05/06
Author (S):
C. CHAVANT, V. GERVAIS
Key
:
V7.31.128-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_EFF”, “LIQU_SATU”, “HYDR_UTIL”
Code_Aster
®
Version
8.3
Titrate:
WTNV128 - Triaxial compression test not drained with the model of Hoek-Brown
Date:
04/05/06
Author (S):
C. CHAVANT, V. GERVAIS
Key
:
V7.31.128-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
- 0.239568
28
xx
- 0.257851
36
xx
- 1.10550
44
xx
- 4.29762
52
xx
- 7.28266
80
xx
- 15.7587
16
yy
- 0.239568
28
yy
- 0.257851
36
yy
- 1.10550
44
yy
- 4.29762
52
yy
- 7.28266
80
yy
- 15.7587
16
zz
- 16.0195
28
zz
- 20.4913
36
zz
- 24.7968
44
zz
- 28.9045
52
zz
- 33.7174
80
zz
- 54.1101
16
Pressure
water
5.23957
44
Pressure
water
0.702380
80
Pressure
water
- 10.7587
Code_Aster
®
Version
8.3
Titrate:
WTNV128 - Triaxial compression test not drained with the model of Hoek-Brown
Date:
04/05/06
Author (S):
C. CHAVANT, V. GERVAIS
Key
:
V7.31.128-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_EFF”, “LIQU_SATU”, “HYDR_UTIL”
Code_Aster
®
Version
8.3
Titrate:
WTNV128 - Triaxial compression test not drained with the model of Hoek-Brown
Date:
04/05/06
Author (S):
C. CHAVANT, V. GERVAIS
Key
:
V7.31.128-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
- 0.239568
28
xx
- 0.257851
36
xx
- 1.10550
44
xx
- 4.29762
52
xx
- 7.28266
80
xx
- 15.7587
16
yy
- 0.239568
28
yy
- 0.257851
36
yy
- 1.10550
44
yy
- 4.29762
52
yy
- 7.28266
80
yy
- 15.7587
16
zz
- 16.0195
28
zz
- 20.4913
36
zz
- 24.7968
44
zz
- 28.9045
52
zz
- 33.7174
80
zz
- 54.1101
16
Pressure
water
5.23957
44
Pressure water
0.702380
80
Pressure water
- 10.7587
6
Summary of the results
This case test is a test of not-regression developed to validate the model of Hoek-Brown modified in
effective stresses, HOEK_BROWN_EFF, with hydraulic coupling.
One obtains the same results with two modelings 3d_HM or 3d_HMS.