I have carbon steel buried piping network to be analyzed in CAESAR-II. Pipes are coated with 25mm concrete for protection against corrosion. The design temperature and pressure are 50degC and 1.6MPa. I have all other parameters needed to generate buried mesh.

My question is whether this approach of analysis is correct for buried coated pipes because mechanical bonding between pipe and concrete coating will offer more resistance to pipe expansion than the resistance offered by just soil. I am getting displacements like 20mm but we know that concrete does not expand that much so in reality I think either the pipe will be more stressed than CII results or the concrete coating will crack open or the pipe will slip inside coating by breaking the mechanical bond. If the coating cracks, it is going to be a serious problem for the health of the pipe.

Please suggest how to address this issue in CII. (Don't ask me to put pipes in tunnel or above ground. Site constraints.)

Thanks,
MAJ