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Abstract
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This paper investigates the effect of clogging
incidents of drilling fluid within a borehole drilled through
an earthfill dam by the 3D numerical analysis. Various
locations and heights are considered for the position of the
clogging zone of the borehole and the stress state and
potential of both shear and tension failures are examined in
the dam core. According to the results, the clogging incident decreases the minimum effective stress and increases
the deviatoric stress in the dam body around the borehole
which can impose tensile and shear failures. If the clogging
incident occurs after the dam construction, tension cracking
occurs in all locations of the clogging zone. However, the
likelihood of tension cracking is reduced after the stages of
steady seepage and consolidation completion. Moreover, if
the borehole clogging occurs at the upper heights of the
dam, a large damaged area with tension cracking and a
high-risk of shear failure are imposed in the core and the
stress decreases in a great zone. Besides, the damage
potential of the clogging incident becomes significant at the
edge of the dam core near the filter zone even during the
steady seepage stage.
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