pore pressure

Question

dear all

I wanted to simulate the effect of sediment deposition on pile foundations on a submarine slope, so here's what I did,

1) clay formation; 2) generate the pile foundation; 3) plasticity calculation (activate silt); 4) Consolidation calculation （ activate silt， time interval = 1 ）；5 ) Consolidation calculation （ activate silt， time interval = 360 ） 
 Bottom hydraulic boundaries are closed at all stages， The result of the model is that the pore pressure of the 4) and 5) phases and the internal force of the pile foundation do not change， then I added a load to the silted soil, and the result was the same. 
 I'm confused， why do stages 4 and 5 appear to have the same effect? Is there a mistake in the simulation process or do I not understand the consolidation calculation？ 
 Looking forward to your answer 
 thank you

Dennis Waterman · Accepted Answer

Dear Xiong qi, 
 Unfortunately you didn't mention anything about what those results from 4) and 5) exactly are, so I can only answer you based on some guessing from my side. So just to give some suggestions: 
 1) Did you generate any excess pore pressures at all in phases 1) to 3) If there are no excess pore pressures there is nothing to consolidate, so then it doesn't matter if you consolidated 1 day or 360 days. 
 2) So it could be that either the permeabilities are very high so that in 1 day or in 360 days all excess pore pressures are dissipated and results are the same 
 3) So it could be that either the permeabilities are very low so that in 1 day or in 360 days almost no excess pore pressures are dissipated and results are the same 
 With kind regards, 
 Dennis Waterman

pore pressure

Top Replies