2D PLAXIS Plate Element - Buoyant Weight

Question

Good day 
 My query concerns the selection of an appropriate weight parameter "w" when modelling a plate element in Plaxis 2D. Does Plaxis automatically account for buoyancy for plate elements that are below the water table? In other words, for a submerged plate element, must the specified weight parameter "w" be based on the equivalent buoyant unit weight of the plate material, or the unsubmerged (i.e. "dry in air") unit weight? 
 Many thanks

Stefanos Papavasileiou · Answer

Dear Nataly and Sam, 
 You are correct as to that PLAXIS does not take into account the buoyancy effects for plate material. 
 This means that the calculation kernel does not adjust the unit weight of the plate based on the elevation the phreatic level is. 
 Therefore, for taking into account the fact that a plate is submerged, the user should manually adjust the unit weight to consider the buoyancy that exists in reality. 
 The above is added extra to any adjustments needed for the case of thick plates which overlap with the soil, as mentioned correctly before. 
 Sorry for the confusion caused regarding this. Indeed, the best solution is always to create a simple model to understand how the program performs the analysis. 
 Thank you, Nataly, for spotting this inconsistency!

2D PLAXIS Plate Element - Buoyant Weight

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