Hello All
Dear Akhila,
With the current implementation of the constitutive models, you will need to calculate equivalent parameters of the material data set that will take into account the improved soil behaviour due to the presence of the fibers. This data set can then be directly assigned to the soil polygons.
Note that it is possible to implement a user-defined soil model that can simulate the behaviour you intend to have. For more information, please check the link below: https://communities.bentley.com/products/geotech-analysis/w/plaxis-soilvision-wiki/45468/plaxis-user-defined-soil-models