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SAMC
o
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• ANNUAL REPORT 2013
in the SAMCoT cruise to the Fram Strait in August-
September studying applicability of hydrostatic weigh-
ing technique for the determination of ice density in the
field conditions. In the autumn she has been working on
an OMAE conference paper about direct shear box tests
together with Arttu Polojärvi and Knut Høyland. The
abstract for the IAHR conference paper about odome-
ter tests and effects of block size, gradation and other
factors on compressibility of rubble ice was submitted
in December 2013. Her current laboratory work mostly
concerns odometer tests.
Frozen soils
In the first half of 2013, PhD candidate Yared Bekele
completed his last course, part of the organized
academic training. During the same period, the devel-
opment of the theoretical formulations required for a
fully coupled thermo-hydro-mechanical (THM) finite
element modeling of ground freezing and thawing
was underway. A state-of-the-art report based on the
topic was prepared and a related conference paper
was published in the proceedings of the COUPLED
2013 (Computational Methods for Coupled Problems
in Science and Engineering V) conference. A second
conference paper presenting the theoretical and finite
formulations has been accepted for publication at the
NUMGE 2014 (Numerical Methods is Geotechnical
Engineering) conference.
Yared Bekele development of a numerical tool for the
thermo-hydro-mechanical (THM) coupled finite element
simulation is a work in progress. A finite element
package from SINTEF Applied Mathematics, called
IFEM, was selected as a working platform.
IFEM stands for Isogeometric Finite Element Method
and is a new alternative approach to the conventional
finite element method. The method uses splines for
numerical integration and has several advantages over
the conventional finite element method. It is believed
that the numerical difficulties in FE modeling of THM
coupled problems may to a large extent be addressed
by the use of this numerical method.
Some of the advantages of isogeometric finite element
analysis over the conventional finite element method
include achievement of local mass conservation and
better continuity of pressures and temperatures by
using splines for numerical integration.
Hierarchical development of the numerical tool starts
with hydraulic (H) implementation for water flow,
proceedingwith the hydro-mechanical (HM) and thermo-
hydro-mechanical (THM) parts to include deformations
and temperature variation.
Figure 33. Gradation of maximum ice block dimension normalized by average thickness plotted from the data obtained in
Barents Sea, years: 2002, 2003, 2004, 2005, 2007.