Hello,
I am currently carrying out analysis on a large diameter pile in Plaxis 2D, with specific emphasis on the contribution of the base capacity. I understand that Plaxis 2D allows you to plot the full Fy reaction force against the displacement across the pile. I was curious to know if it is possible to get this Fy force from the shaft and the Fy force from the base separately, rather than as one total force, or what is the best method for obtaining the shaft and base capacity separately from a pile in Plaxis 2D.
Moreover, I was comparing the two soil constitutive models of the HSsmall model and the Mohr Coulomb model model. I was intrigued to know if the dilatancy cut-off option is also available in the Mohr Coulomb model Model, or if there is a reason why it is only an option in the HSsmall model.
Thanks,
John
Hi John,
If you want to get the individual contribution of the shaft and the base in a PLAXIS 2D pile model, you will need to retrieve the stresses of the shaft (shear stress in the interface) and the foot (vertical stress just below the pile's foot) and integrate these to go from stress to a total force.I think the Fy you refer to is the total reaction force caused by a prescribed displacement (see Force Fx, Fy and Fz. What are these parameters?)
Note that if you want to balance this Fy with your calculations, please take into account that the soil already contains stresses before you start loading the pile, so then there will be a difference.
For the second question, indeed only the Hardening Soil models (Hardening Soil, HS Small) have a dilatancy cut-off option.
By the way, I assume you only do a vertical loading of the pile in PLAXIS 2D using an axisymmetric approach? See e.g. this article: communities.bentley.com/.../points-of-interest-for-pile-modelling-in-a-2d-plane-strain-model