Dear all.

I would be grateful if someone can help with this doubt about stress results in underground pipeline.

My question is related to how Caesar II calculate Stress Equivalent in Restrained areas (B31.4 402.7 Combining of Stresses Seq). Applying the formula Seq=sqrt(SH^2-SH*SL+SL^2+3St^2) we obtain different values than from Caesar II Output Stresses (Multiple Code/Allow) Comb column. Indeed, it seems that Caesar II divides the result between 0.875, but this as far as I am concerned, does not apply on Seq calculation, it is already included on the 0.9 SMYS of the Comb Allowable.

Resuming, it seems that Caesar II is applying the mill tolerance factor on Seq, and from my point of view it should only be imposed on Comb Allow through 0.9 factor over SMYS.

Thanks in advance.