pipe-soil interaction

Hi,

I read ASCE method papers and autopipe soil tutorial, but I still dont understand should I place an anchor in the virtual anchor location or this is done by autopipe itself. While analysing results, I see than longitudial appears even after virtual anchor length. Is it correct? 

Here I attach my model. I entered 1000 mm spacing though it is too small for many regions because no convergence problems accured. It only affects computational time, am I right?