If the spreader bars are uncertified and there is no traceability of material certificates, don't use them.
I am confused in the calcuation how the compression strength of the material is 410 MPa and the yield strength is 245 MPa. ???
According to the CISC Design Guide for Crane-Supporting Steel Structures "side thrust is distributed to each side of the runway in accordance with the relative lateral stiffness of the supporting structures."
In the AISC ASD design code, Fy, is defined as the specified MINIMUM yield strength for the type of steel being used. Consequently, I would advise against using Mill Test Certificate values as the basis for performing your design.
Nonetheless, I have seen MTC values used for existing...
The design of corrugated or crimped plate bulkheads is covered in the following publication which is available for download on the American Bureau of Shipping (ABS) website:
ABS GUIDE FOR BUCKLING AND ULTIMATE STRENGTH ASSESSMENT FOR OFFSHORE STRUCTURES, Section 3.0