In view of the above-mentioned specifics of columnar ice modeling, the flexural
and shear strength values given in Table 4 should be referred to the upper consolidated layer, while the compressive strength should be referred to the lower
layer.
It is interesting to compare the data in Table 4 with the ice strength properties
obtained by conventional methods (Table 2). Both tables give flexural ice strength
parameters and indenter pressures, though not at all tests.
We emphasize the following results:
• The sea ice flexural strength values are quite close both under the vertical
loading of a cantilever ice beam and under horizontal loading of a clamped
beam despite different test procedures applied. The tests performed by the
authors to find the flexural strength of seawater ice in the horizontal plane using
cantilever ice beams have not revealed any major differences.
• It was found in the tests with fine-grained ice that the ice flexural strength in the
horizontal plane decreases substantially (almost 10 times) as compared with the
vertical flexural strength, while the model columnar ice feature a substantial
(almost 4 times) increase in this parameter. It should be taken into account that
different test procedures were applied during vertical and horizontal bending of
ice beams, and conclusions should reasonably be drawn from the data obtained
by similar test procedures. However, this issue was beyond the scope of the
study.
• Lower indenter pressures for the model ice presented in Table 4 as compared
with Table 2 are generally explained by the differences in the boundary conditions: free boundaries in the case of indenter penetration into an ice beam and
without such boundaries in the case of boundless ice sheet.
Table 4 Strength parameters of ice (according to beam tests with fixed ends)
Ice type
Beam#
p ind
formula (1)
(kPa)
σ f
formula
(2) (kPa)
σ c
formula
(3) (kPa)
τ s formula
(4) (kPa)
σc
σf
Sea ice
Sea1_L
351
4085
11.6
Sea2_M
483
3609
7.5
Sea3_S
343
Model ice/FG
fine granule
FG1
1.5
1.6
1.1
FG2
0.7
1.4
2.0
1.4
FG3
1.1
1.2
1.7
1.4
Model ice/
columnar
Col3
134
122
0.9
Col4
176
140
0.8
Col6
169
42
Col5
226
41
606
M. Karulina et al.
and shear strength values given in Table 4 should be referred to the upper consolidated layer, while the compressive strength should be referred to the lower
layer.
It is interesting to compare the data in Table 4 with the ice strength properties
obtained by conventional methods (Table 2). Both tables give flexural ice strength
parameters and indenter pressures, though not at all tests.
We emphasize the following results:
• The sea ice flexural strength values are quite close both under the vertical
loading of a cantilever ice beam and under horizontal loading of a clamped
beam despite different test procedures applied. The tests performed by the
authors to find the flexural strength of seawater ice in the horizontal plane using
cantilever ice beams have not revealed any major differences.
• It was found in the tests with fine-grained ice that the ice flexural strength in the
horizontal plane decreases substantially (almost 10 times) as compared with the
vertical flexural strength, while the model columnar ice feature a substantial
(almost 4 times) increase in this parameter. It should be taken into account that
different test procedures were applied during vertical and horizontal bending of
ice beams, and conclusions should reasonably be drawn from the data obtained
by similar test procedures. However, this issue was beyond the scope of the
study.
• Lower indenter pressures for the model ice presented in Table 4 as compared
with Table 2 are generally explained by the differences in the boundary conditions: free boundaries in the case of indenter penetration into an ice beam and
without such boundaries in the case of boundless ice sheet.
Table 4 Strength parameters of ice (according to beam tests with fixed ends)
Ice type
Beam#
p ind
formula (1)
(kPa)
σ f
formula
(2) (kPa)
σ c
formula
(3) (kPa)
τ s formula
(4) (kPa)
σc
σf
Sea ice
Sea1_L
351
4085
11.6
Sea2_M
483
3609
7.5
Sea3_S
343
Model ice/FG
fine granule
FG1
1.5
1.6
1.1
FG2
0.7
1.4
2.0
1.4
FG3
1.1
1.2
1.7
1.4
Model ice/
columnar
Col3
134
122
0.9
Col4
176
140
0.8
Col6
169
42
Col5
226
41
606
M. Karulina et al.