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th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
strength of soil in the entire failure plane to the residual shear
strength and global failure will occur.
7. REFERENCES
Figure 4 shows the variation of shear stress at 4 different
locations A, B, C and D (Fig. 1) which are located from the
vertical face of the excavated/eroded block at horizontal
distance of 3 m, 12.5 m, 25 m and 35 m, respectively. Consider
the soil element B at 12.5 m distance. The shear stress in this
element is increasing with movement of the excavated/eroded
soil block. When the block is displaced by an amount of 115
mm, the shear stress in this element is reached to the peak shear
strength of the soil (50 kPa). However, at this displacement of
the block, the element A is almost at the residual shear strength.
On the other hand, the elements C and D are still in the pre-peak
state. That means the shear stress is gradually transferred to the
soil elements in the right with displacement of the
excavated/eroded soil block. For the soil element under the
slope of the river bank there is an initial shear stress. With
movement of the block the shear stress is increased from that
initial value. However, the initial shear stress is less in the
elements far from the river bank. Similar variation in shear
stress and mobilized shear strength are obtained for Case-I and
II.
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5. CONCLUSION
This paper presents a new numerical approach to model the
initiation and propagation of shear band in upward progressive
failure as encountered near the river banks. Toe erosion is
considered as the triggering factor. Coupled Eulerian-
Lagrangian (CEL) approach currently available in ABAQUS FE
software is used for numerical analysis. Nonlinear strain
softening behavior of sensitive clay is incorporated in this large
deformation finite element analysis. Three cases are analyzed in
this study. In Cases I and II global failure is occurred. However,
in Case-III, although global failure is not occurred, the shear
band propagation reduced the shear strength in the potential
failure plane significantly over a large distance and the slope
might be marginally stable for further loading.
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and the Associated Hazard and Risk to Linear Infrastructure.
Doctoral thesis, Queen's University.
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6. ACKNOWLEDGEMENTS
The writers would like to acknowledge the financial support
from Research & Development Corporation of Newfoundland
and Labrador and C-CORE.
