Abstract
Abstract
This study evaluates how diaphragm-wall cracking and hydraulic anisotropy jointly affect seepage discharge and downstream slope stability in earth dams. A coupled two-dimensional numerical framework was developed by transferring pore-water pressures obtained from steady-state SEEP/W analysis into SLOPE/W limit-equilibrium stability analysis. The numerical database contains 105 full-factorial scenarios combining the anisotropy ratio
K
y
/
K
x
= 0.0001–1.00, the crack-width ratio
t
/
H
= 0.01–0.50, and the crack-location ratio
y
/
H
= 0.25–0.75. The results show that increasing
K
y
/
K
x
and
t
/
H
intensifies seepage through the cracked diaphragm wall and reduces the factor of safety (
FS
), whereas increasing
y
/
H
reduces the hydraulic severity of the defect. Across the studied domain,
q/(K
y
H)
varies from 0.006 to 0.180 and
FS
varies from 1.979 to 0.533. Comparison with the benchmark field-scale diaphragm-wall model gave differences of 3.33% in seepage discharge and 0.27% in
FS
. Four tree-based models, namely random forest, extra trees, gradient boosting, and XGBoost, were developed as numerical surrogates for
q
/(
K
y
H
) and
FS
. Gradient boosting achieved five-fold out-of-fold R² values of 0.9950 for
q
/(
K
y
H
) and 0.9959 for
FS
. SHAP analysis identified
K
y
/
K
x
and
t
/
H
as the dominant controls on seepage discharge, while
K
y
/
K
x
was the dominant control on
FS
. The study quantifies the coupled effects of crack geometry and hydraulic anisotropy and provides an explainable numerical screening approach for cracked diaphragm walls within the investigated parameter ranges.