KOD
I apologize for this late answer and I thank you for the information related to ClassNK.
1. We noted that ClassNK will require a proof load test.
The current mooring system design consider 132 mm grade R4 chain, the MBL being 15965 kN.
For such chain link, the proof load provided by Vicinay on their online documentation is 11187 kN.
Could you please confirm that this proof load value is the one required by ClassNK ?
In calculation note referenced H01-CN-MEC-5510 rev C3, the accidental load case is considered with a mooring line tension ALS1=12772 kN, that is to say 14% superior to the proof load tension.
Regarding the results from p34 to 44, the mooring connector and associated washers and bushes can withstand the proof-load test with no yielding or failure for the polymer bushes.
In case the mooring steel foundation needs to be proof-loaded, there will be very local yielding depending on the equivalent mooring line angle for the proof-loading.
2. I attached a new standard from DNV “Support structures for wind turbines” where useful information related to offshore bolt connection can be found. Generally it makes reference to European standards “Eurocode”.
One example of similar structure on which we based our mooring interface structure design on Floatgen project are the lifting points of Gravity Based Structure of Thornton wind turbine foundation (about 750 t per lifting point). I attached related documentation to this email where concrete structures with multiple concrete bolts can be seen.
Some projects example can be found on this tensioning bolt supplier, but I suppose you have very similar projects in Japan.
http://www.macalloy.com/projects
We hope we provided useful information, for additional request please let us know.