Grade Beam Modelling with moment Frame

Choose the frame fixity based on engineering judgement. It can be fixed or pinned. This might be based on the base plate condition for example. The fixity of the frame columns above certainly impacts the forces and the design. Regarding drift, you want to set the Criteria - Ground level to the grade beam level most likely. https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/18422/ram-frame---criteria---ground-level 

Choose the frame fixity based on engineering judgement. It can be fixed or pinned. This might be based on the base plate condition for example. The fixity of the frame columns above certainly impacts the forces and the design. Regarding drift, you want to set the Criteria - Ground level to the grade beam level most likely. https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/18422/ram-frame---criteria---ground-level 

Hi Seth,
Thank you for the reply.
I understand that the frame fixity should be based on engineering judgement.
I just want to get clarification about grade beam modelling. Is that necessary to model?
Does the result provided from grade beam modelling can be used?
Please share your views on this.

Personally, I prefer to leave out the grade beams and design them separately.  If you want partial fixity at the base of the main model to approximate flexibility of the foundation, that can be handled with foundation springs.