ETL 1110-2-344
31 Dec 93
Figure A-5. Pressures from backfill in vertical direction
Figure A-6. Pressures from backfill in horizontal direction
The equivalent nodal forces fσ0 for the elements
for plane strain. The negative sign on the pore
pressures p in Equation 6 reconciles the difference
subject to the initial stresses are computed as a
between the sign conventions for soil mechanics
volume integral over the element domain
and standard solid mechanics. The pore pressures p
correspond to full uplift for those elements adjacent
⌠ B Tσ dV
fσ
(7)
⌡V
to the crack surfaces and vary linearly in the hori-
0
0
zontal direction from full uplift at the crack tip to
zero (empty lock chamber) at the toe of the mono-
where B is the strain-displacement operator.
lith. The initial stresses are constant in the vertical
Because the initial stresses are hydrostatic, the equi-
direction at a given horizontal distance from the
valent nodal forces act in both the horizontal and
toe.The pore pressure distribution over the elements
vertical directions. Elements subjected to initial
adjacent to the interface is shown in Figure A-7.
A-7
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