I don't think I'm clear on the question.

When you bury a model in CAESAR, CAESAR adds and/or replaces existing restraints with restraint nodes, based on the properties of the soil and pipe.

When you have a thrust block, that means that actual soil resistance will be higher due to increased surface area at a given point.

The net result may be impactful or may be negligible.

If my back were to a wall to estimate an arbitrarily-sized block's impact, I would determine the lateral soil resistance of an appropriately long and diameter line, and changing axial and lateral restraints appropriately in my "real" model.