Figure 58.1: Problem Geometry shows the geometry of the example problem with the suction pile skirt and cap and the inner and outer soil region. The suction pile is surrounded and partially filled with a sand-like soil with a low level of cohesion. Loading conditions include active and passive radial earth pressure on the outer and inner suction-pile surfaces.
A nonlinear static analysis with nominal geometry is performed using a specific loading history. Initially, the in-situ stress state is applied, accounting for the weight of the surrounding soil, which changes as a function of soil depth, and Poisson's ratio. The suction pile is further loaded with negative pressure, interface forces caused by the suction pile interacting with the driving structure, and additional friction forces between the pile skirt and the soil.
The resulting stress state is used as input for a linear buckling analysis to obtain the buckling modes related corresponding to the load state. Geometric imperfections are created from the deformation shape of the first buckling mode and a specified scaling factor.
After updating the geometry to account for imperfections, a subsequent nonlinear static analysis is performed. Compared to the results of the earlier static analysis with nominal geometry, the stress-state and deformation results are markedly different.
