Dear Yip,

Soil nail can be modelled in PLAXIS using beam element as available in PLAXIS library..which year version are you using in your work..PLAXIS is having tutorial manual as similar to your work so i recommend to you to simulate tutorial problem first and than after familiar with the software, you simulate for your problem.. ok all the best in your work..

You could use embedded beam element available in PLAXIS

Hi

It should be better to define the additional step based on the Phi C reduction. This step will give you the FS of soil model.

In addition you can simply use Geo-slope to find the FS.