To evaluate the effect of the strain-softening of structured clays on the vertical bearing capacity of the spudcan foundations

firstly

the VUSDFLD subroutine was used to define the relationship between the undrained shear strength and accumulated absolute plastic shear strain

so that the coupled Eulerian-Lagrangian (CEL) numerical analysis method can simulate the strain-softening effect of structured clays. Then

based on the improved CEL numerical analysis method

the effects of soil sensitivity

soil strain-softening parameter

and soil brittleness parameter on the soil backflow above the spudcan as well as on the vertical bearing characteristics of spudcan foundations were analyzed. The results show that soil sensitivity

soil strain-softening parameter and soil brittleness parameter all have impacts on the soil backflow and on the vertical bearing capacity of spudcans

in which the effect of the brittleness parameter is most significant. Also

compared with the situation without considering the strain-softening effect

the bearing capacity factor of spudcan foundations and limiting cavity depth considering the strain-softening effect of structured clay are dramatically lower. Finally

the prediction expressions of the normalized limiting cavity height and vertical bearing capacity of spudcan foundations in structured marine clay were established

and the prediction results are reasonable. The research results of this paper can be used to assess the bearing capacity and penetration depth of spudcan foundations in practical engineering.