A parametric study on the vertical pullout capacity of suction caisson foundation in cohesive soil

The pullout capacity of suction caisson foundation plays a vital role in its field performance. This study presents numerical investigation on the vertical pullout capacity of suction caisson foundation in cohesive soil under both drained and undrained conditions. The influence of soil cohesion, internal friction angle and caisson aspect ratio on the ultimate vertical pullout capacity of suction caisson foundation has been investigated. It is noted that the upper limit of pullout capacity is governed by undrained condition and the lower limit by drained condition. The pullout capacity increases with increasing soil cohesion, friction angle and caisson aspect ratio when caisson diameter is kept constant, whereas it decreases with increasing caisson aspect ratio when caisson length is kept constant. Mathematical models have been developed for both drained and undrained pullout capacity. The pullout capacity values have been compared with those of available analytical and simplified relationships, and it has been found that the developed models can accurately predict the vertical pullout capacity of suction caisson foundation.