Are there ane posibilities in Caesar to see dependense of model analisys ongaps in the restrains.

I tried to do it
but modal analisys showed error message
Please Help if it is possible

Run a static analysis first and then point to one of the completed static load cases in the Dynimic Control Parameters to set the "state" of the nonlinear supports.
CAESAR II must make all restraints linear for dynamic analysis. If the restraint is closed or active in the static case, the linear support is included in the dynamic model. If the restraint is open or inactive in the static load case you select, the restraint is excluded from the modal analysis.

I mean how can I organize movement of the node (where restrain is placed)
so that spring will work not all the way
for example 5 mm - gap and only after that spring with C=....N/cm begin working..

Do you mean free motion for 5 mm before the spring stiffness begins?
NODE=xx, TYPE=X,Y,Z or "skew", GAP=5, STIFF=xxx

Or will that spring be preloaded so that once teh 5 mm gap closes, the pipe must first overcome that preload before the pipe continues motion? I'll have to think about that...

No, I do not mean preloaded spring
I whantto say that, there is gap XX and after pipe in this node moved on XX - spring becomes it's deformation..

for example in this way we can simulate unproper construscing of restrains in this node by workers on real pipe.
yes?

I am a little confused.
Tell me what's wrong with my first suggestion:

For free motion of 5 mm before the spring stiffness begins use -
NODE=xx, TYPE=X,Y,Z or "skew", GAP=5, STIFF=xxx

possibly? I don't understand you but here on picture - is situation what I mean
http://www.photoshare.ru/photo2321516.html

You were talking about it?

I am unable to reach your link

I think what Rafitop is trying to say is: (correct me if Im wrong)

Allow the pipe to delfect or lift-up to a 5mm clearance before it hits a support with specific stiffness (spring). I believe that Dave's interpretation to make the certain support is correct.

Goodluck!

Yes exactly, what Flexy105 has wrote)!
and how to make it?

or it's impossible?

No non-linearities in Dynamics.