API 650 U Anchored Tanks supported by Grillage Beam 2

[Modeo]

Hi,
I'm working a sulfuric acid tank designed on API 650. From calculation, the tanks requires anchorage and the client requests to provide grillage beam supporting as leak detection technique.

The client provides to us drawings of anchor details he got on a similar tanks. (see attached)

Any ideas of standards, codes or references to design U-bolts and considering at the same time anchorage requirements of API 650.

Thanks in advance

 

[fegenbush]

In API 650 12th Edition, Addendum 3, paragraph 5.12.7 recommends using the AISI Steel Plate Engineering Data Volume 2 Part 5. Using the procedure in that standard and making your U-bolts from ASTM A36 material, it is possible to treat these as anchor chairs.

Given that this is a non-standard application, there is going to be a lot of using Recognized and Generally Accepted Good Engineering Practice to make the final call. Please let me know if you have a specific question, and I will help how I can.

 

[Geoff13]

The 6 mm pad plate on the shell is a terrible idea for any anchor chair. The chair should attach directly to the shell.

Watch out for the requirement for full yield embedment of the bolts (5.12.12 in 12th Ed, 2nd Add), which would two bolt yields as a point load on your beam bottom flange.

An interesting question would be what is the strength of the bolt? It will first yield in bending on the horizontal portion of the u-bolt. This will be a permanent deformation and now the bolt won't be tight. With additional applications of the load (wind, internal pressure) the tank will have to lift before the bolts becomes effective. I would be very reluctant to use this bolt detail.

 

[Modeo]

Thanks fengenbush and Goeff13 for your answers.

Indeed, I checked AISI Steel Plate Engineering Data Volume 2 Part 5 but adapting this model by some assumptions is another study to do.

Fegenbush, can you suggest me some Recognized and Generally Accepted Good Engineering Practice's docs to investigate ?

For the project, we decided to go for FEM calculation.

Thanks again for your helps.