how to apply dynamic loading at the base of model

Question

I want to apply (input) a dynamic load of sinusoidal wave which is having a frequency of 20hz and amplitude of 5m/s2 at the base of model how can I apply that? 
 Secondly, how can I use UBC3DPLM model for liquefaction and how can I get pre and post liquefaction output? 
 Rahul Dogra

Stefanos Papavasileiou · Answer

Dear Rahul, 
 I would advise you to follow our Pile driving tutorial example that demonstrates a similar case: https://communities.bentley.com/products/geotech-analysis/w/plaxis-soilvision-wiki/45567/plaxis-2d-tutorial-15-pile-driving 
 
 As for the UBC3DPLM, I am not sure what you are looking for. I would start by checking the documentation on the parameters. We already have an interesting article on our Wiki page about liquefaction: https://communities.bentley.com/products/geotech-analysis/w/plaxis-soilvision-wiki/46050/site-response-analysis-and-liquefaction-evaluation

Stefanos Papavasileiou · Answer

Dear Rahul, 
 Apologies as I missed the part that you mention that you want to apply the signal at the model bottom (base). The example I sent you shows how to configure a sinusoidal signal but of course explains a case where the dynamic source is from inside the model. 
 Instead, you can check the tutorial example of modelling an earthquake response: https://communities.bentley.com/products/geotech-analysis/w/plaxis-soilvision-wiki/45568/plaxis-2d-tutorial-16-free-vibration-and-earthquake-analysis-of-a-building 
 And this article can also come in handy: https://communities.bentley.com/products/geotech-analysis/w/plaxis-soilvision-wiki/45984/on-the-use-of-dynamic-boundary-conditions