We are constructing a double wall ammonia storage tank. Annular plates 12 mm were laid down and welded from both sides. After completion of annular ring 4 no of base plates 18" x 12" x 12 mm (for strap connection) were welded on each annular plate each using 4 fillet weld passes. Now problem is we are facing permanent distortion (i.e. annular ring lifted upward from inside) of maximum 4 inches from bottom. Expert opinion is required to rectify this issue.

We have installed Z type temporary anchors to pull back distorted plates to their position until inner shell is placed on annular plates (at the center approximately). This is because we are hoping that once inner shell load is placed distortion will be compensated but if not then what should we do?

Immediate response will be highly helpful.

Some pics are attached for understanding.

• https://files.engineering.com/getfile.aspx?folder=0b85d7d3-0ad3-49ff-9135-a