Numerical Simulation of Vertical Pullout of Plate Anchors in Clay
Abstract: The behavior of strip and circular plate anchors during vertical pullout in uniform and normally consolidated clays was studied
in this paper by means of small strain and large deformation finite-element analyses. Both fully bonded attached, and “vented” no
suction on rear face, anchors were considered. The current numerical results were compared with existing laboratory test data, finiteelement
results, and analytical solutions. This study showed that, in small strain analysis, the scatter of existing data was mainly due to
the effect of soil stiffness. In large deformation analysis, when soil and anchor base were attached with suction, the pullout capacity factor
formed a unique curve independent of the soil strength su, soil effective unit weight and anchor size Bwidth of strip anchor and
Ddiameter of circular anchor. The transitional embedment depth ratio, HSD/B or HSD/D, where HSDtransition depth between shallow
and deep embedment was 1.4 for a strip anchor and 0.75 for a circular anchor. The ultimate pullout capacity factors Nc for deep
embedment were 11.6 and 11.7 for smooth and rough strip anchors and 13.1 and 13.7 for smooth and rough circular anchors, respectively.
However, when the anchor base was vented, the soil stayed attached to the anchor base for deep embedment, and the pullout capacity was
therefore the same as for the attached anchor. The separation depth ratio, Hs /B or Hs /D, where Hsembedment depth at which the soil
and anchor base separated was found to increase linearly with the normalized strength ratio, su /B or su/D.
DOI: 10.1061/ASCE1090-02412008134:6866
CE Database subject headings: Anchors; Pull out resistance; Soil strength; Deep water; Finite element method; Deformation.