Hey guys, new user here. I am working on modeling PIG traps for work and am having a few problems understanding whether what I am doing is accurate. I'm modeling a 42" Pig trap and working on the buried section. I have already buried it several times to test the VAL and came up with a value of 393 feet. I am using twice the VAL for conservative results. I did not, however, place a hard anchor at the first node. Is this a good standard practice?

Secondly, I was getting ridiculously high bi-linear restraint values when I would bury the pipe (stiffnesses over 2 million psi, and a yield load of 3 million lbs). I was suspicious of this and read through the Caesar and Autopipe manuals to get a better idea of soil restraint properties and calculations, since I'm mechanical, not civil. I saw that there are equations for distances between soil restraints and when I checked the model I realized that were only 2 spans of well over 300 feet in the buried model. So I went in and added nodes so that the model will better match the equations provided in the manual. This decreased the bi-linear restraints, which seems more realistic, but when I compared the analysis results, the stresses and loads increased quite a bit. Is this simply a more accurate result or did I mess up Caesar's modeling?