Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Transversely isotropic poroelastic behaviour of the Callovo-Oxfordian
  claystone: A set of stress-dependent parameters   In the framework of a deep geological radioactive waste disposal in France,
the hydromechanical properties of the designated host rock, the
Callovo-Oxfordian claystone (COx), are investigated in laboratory tests.
Experiments presented in this study are carried out to determine several
coefficients required within a transversely isotropic material model. They
include isotropic compression tests, pore pressure tests, and deviatoric
loading tests parallel and perpendicular to the bedding plane. We emphasize the
adapted experimental devices and testing procedures, necessary to detect small
strains under high pressures, on a material, which is sensitive to water and
has a very low permeability. In particular, we discovered a significant
decrease of elastic stiffness with decreasing effective stress, which was
observed to be reversible. In both isotropic and deviatoric tests, a notable
anisotropic strain response was found. The Young modulus parallel to bedding
was about 1.8 times higher than the one perpendicular to the bedding plane. A
notably low Poisson ratio perpendicular to the bedding plane with values
between 0.1 and 0.2 was evidenced. While the anisotropy of the back-calculated
Biot coefficient was found to be low, a significant anisotropy of the Skempton
coefficient was computed. The performed experiments provide an overdetermined
set of material parameters at different stress levels. Using all determined
parameters in a least square error regression scheme, seven independent elastic
coefficients and their effective stress dependency are characterized.
Parameters measured under isotropic loading are well represented by this set of
coefficients, while the poroelastic framework with isotropic stress dependency
is not sufficient to describe laboratory findings from triaxial loading.

22
The categories of this paper are: chao-dyn
20
The categories of this paper are: acc-phys
16
The categories of this paper are: stat
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
29
The categories of this paper are: funct-an
28
The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
7
The categories of this paper are: hep-th