I just came across some problems with the implementation of the “Sand Hypoplasticity Model” in Plaxis. I wanted to to perform a simulation of an oedometer test on a material for which i know the hypoplastic parameters using the soilt test tool in plaxis. While for the triaxial test every thing seems to work out quite well, i can’t manage to get proper results for the oedometer test. The strange thing is, during the test i get vertical strains with no change of the vertical stresses. It just shows a straight line within the epsilon1-sigma1-diagram. I have tried to check it with different sets of hypoplastic parameters (different materials) but still i get equal results. Is there any specific input i have to enter to make the oedometric test in Plaxis work in combination with the Sand Hypoplasticity Model. When using for example simple elasto-plastic contitutive models, its no problem to perform the oedometer test. What could be the problem?
Regards Manuel Winkler