Anchorage as Per API 650

Only one bolt? Take more bolts use smaller ones? Strongly recommend to have another engineer in your company looking at this. Noone here will be liable if giving advice but you are. Also what exactly did you calculate? You haven't had any reply because no one sees what you have done.

Even it is a big bolt its better save than sorry.

The OP stated 36 56mm (2-1/4 inch) anchor bolts around a 62 meter circumference. Anchor spacing would be about 1.75 meters. This does not sound unreasonable.

"36 nos" did not compute as numbers when flying over it. Anyway more than to say it sounds reasonable does not seem possible.

I should have added, while the numbers appear to be reasonable thy may not be necessarily correct.

That anchor spacing seems a bit long....can the OP recalculate with more anchors closer together and then possibly come up with a more common, smaller bolt size.

I haven't spotted foundation hold down bolts this big before, have I led a sheltered life?

A difference of words:

• Anchorage, a town in Alaska.

• Anchorage, a mechanical fastening device.

The size of the bolts is quite large. In Nevada the water storage tanks are set with no hold down bolts, the bottom is welded together onto a concrete pad with embedded steel weld anchors that are welded to the tank bottom as it is being fabricated.

I know Nevada isn't in a "Seismic" zone but I think your calculations are off.

Possibly the "seismic" values

The anchor bolt requirements do not sound that unreasonable. We have done projects in Chile where they have pretty substantial seismic requirements and we have in some cases put two circles of anchor bolts on equipment (one inside and one outside of the vessel skirt).

I would have a local civil engineer review the calculations as a sanity check and just to be sure.