Triaxial test in PFC 7.0

I need to calibrate the microparameters of the soil by simulating the triaxial test in PFC. Can anyone help me with the coding? I have found an example of “Sleeved triaxial test of a bonded material” in Flac 3D examples
which is running fine in PFC, but I am still not able to calibrate after several trials. Do we need to modify that triaxial code for use in PFC software.
In my case, I’m simulating the triaxial test by making the boundary flexible and using dry sand as the material. I am using the linear contact model for walls and the rolling resistance model for sand. Please suggest the appropriate changes.

I would suggest looking at the Material modelling support files too for triaxial tests.
The linear model implemented here can be modified into a RRlinear model. Usually if using the bulk calibration approach along with RRlinear model, the parameters like effective modulus, interparticle friction, stiffness ratio and rolling resistance friction needs to be iterated till the simulated response matches the bulk response. Several parameter combinations could result in a match and finding a suitable set which matches both the shear and volumetric response is challenging. However, a trial and error approach could be adopted to calibrate the model.