Installation process of suction caisson (pile)

Question

Hi people, 
 I have a question of the installation process of the suction caisson (pile) foundation of offshore wind turbine. Since I already review the tutorial of &ldquo;Loading of a suction Pile&rdquo;, I&rsquo;m wondering if I can use Plaxis 3D model to create a procedure of the installation of suction caisson (pile). Following are the project descriptions: 
 The installation of suction caisson foundation is performed in two phases. (a) self-weight penetration and (b) suction assisted penetration. During self-weight penetration, the foundation is kept on the sea bed soil and allowed to penetrate under its own weight for a while. When self-weight penetration is over, a seal is formed around the bottom skirt of foundation and now it is ready for the second phase penetration. The water is pumped out through the provision provided at the top of caisson generating suction beneath the foundation which allows caisson foundation to penetrate to the desired depth. 
 I&rsquo;d like to observe the seepage curve, permeability, total displacement, and principle effective stresses of the soil while suction caisson is penetrating to the desired depth. If the above can be carried out successfully, then perform the following test of loading capacity. Hope to gain a more accurate outcome. 
 Best Regards

Stefanos Papavasileiou · Answer

Dear Chia-Wei, 
 Based on the description you have sent us, unfortunately, it is not possible to model this with finite elements, e.g. PLAXIS 3D. 
 From the information, it seems that this concern a large displacements problem that goes beyond what PLAXIS 3D can do in this case. 
 In general, the installation effects go beyond what any finite element software can simulate. 
 Note that any techniques mentioned in the literature (e.g. press-and-replace) or used by engineers are always approximations rather than full models simulating the effects that take place in such a situation.