Dear Ramesh,

Are you using PLAXIS new version or old version..in new version geogrid itself an element tool available so you could use that element to simulate geogrid..if you are using old version in this case you have to follow some assumption (the behaviour of geogrid is rigid and linear in nature) and based on the assumption you can use plate or shell element to simulate the geogrid..it is better to use plate element to simulate the model. ok all the best..

Thanks Sir @karthigeyan.I am using plaxis 2018 version.

Dear Ramesh,

You verify from PLAXIS manual, if you are using 2018 version then definitely you have geogrid element. I suggest you to see from PLAXIS manual..ok all the best pa..

Which version of PLAXIS 3D are you using?

I'm using plaxis 2018 version@ali ahmadi.

I'm mainly facing problem with interface of geogrid and soil ,which property should be used to define interface element in materials.

Dear Ramesh,

In PLAXIS interface is simulated in an indirect manner such as use interface factor 'Rf' for soil is 0.67 and 'Rf' for geogrid is 1. if you use plate element to simulate geogrid then in this case interface is automatically created in PLAXIS. plate element is a structural element therefore interface not reguired. if you use geogrid element available in 2018 version in this case use Rf factor to define interface..ok all the best..

You can directly add the geogrid layer using the option and changing the interface for soil-structure interaction.

Add interaction coeff. between soil and geosynthetics and again run the software