Dear Souvik Roy ,

First of all, if you are dealing with a symmetry geometries and boundary conditions, you may want to activate the "Weak Spring" option in "Analysis Setting" that is going to add a spring element automatically to your model and avoid rigid body motion. Since you did not say anything regarding the BCs, I can't say this is the solution for your problem.

If you want to apply the springs, then you need to follow these steps.

Add a "Connections" to your model in case you don't have one in your analysis. Then Under "Connections", insert "Spring". There are two option available for defining a spring which are Body-Body and Ground-Body options. In your case, I think that you need to use Ground-Body one. You can define the Ground side using Cartesian coordinate and on the other side you can select either point, line or surface from your geometry.

Since you mentioned that you want to put constrain longitudinally and laterally, then you need to apply two springs in those directions.

Hope this get you started.

Dear Hamidreza Ahmadi Moghaddam ,

Thanks a lot for your valuable inputs. It got me started for sure. :)

About boundary conditions, I am planning an elastic foundation for both of the asphalt base layer and asphalt shoulder. I am adding an elastic support from static structural to simulate this condition (Though I am open to any other suggestions). Also I tried with the "weak spring". Applying which I received a warning message stating, "One or more bodies maybe underconstrained and experiencing rigid body motion. Weak springs have been added to attain a solution."

Also with the weak spring option I want to try to introduce a non-dimensional joint stiffness as a property of the connections which will simulate the aggregate interlocking between two interconnecting concrete slabs.