What kind of foundation is this?

[JStephen]

This is a screen-grab from a video where they're setting a very large vessel in place.
The foundation has a row of anchor bolts sticking up for the vessel.
But around the edge of the foundation is what looks like a row of bolts holding it down.
Anyone know what's going on there? Just curious!

And it's from this video, towards the end:

https://www.youtube.com/watch?v=aGO020ZBRtY

 

[dhengr]

Jstephen:
Looks like they might have been looking for some additional anchor bolt embedment in the deeper conc. foundation for wind and EQ overturning. Although, exactly how and why is tough to tell without more info. Alternatively, the inner set of A.B’s. on their vessel chairs, and on a somewhat smaller bolt circle dia., must transmit the primary moments from the vessel to that octagonal base. That octagonal base could be a steel fabrication which is also a leveling base for the column, leveling nuts below and finally grout below, and that base could be shop drilled/match drilled to fit with the vessel base flg. Then the moments/tensile loads are taken down to the conc. foundation at a slightly larger bolt circle radius. It seems to me that I’ve seen this steel sub-base detail before, but other than the above, I’m not sure of all the why’s and wherefore’s. These kinds of A.B. arrangements show up on wind turbine towers too.

 

[Trestala]

From my past experience with a major oil company, they have a configuration where the bolts holding down the vessel aren't embedded to the concrete but are surrounded with pipe sleeves with an end plate which carries the tension from the bottom of the octagonal base to the top of base ring (there are two nuts above, and two nuts below the octagonal base). The octagonal base is then held down by those outer bolts. The inner circle bolts could be removed without lifting the vessel and without destroying the concrete. You can simply rotate the bolts and pull it out.

 

I think what I see is the skirt, joining the PV about 60% up from the bottom flange. As noted already, they want this PV to be seriously well anchored.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[r6155]

As mentioned by RaymondN anchor bolts are DIN 7992. I do not think these bolts are used for this tower
See

https://www.youtube.com/watch?v=YK2Sgg94BVo

Regards
r6155

 

[Dhurjati Sen]

Dear Stephen,

This vessel would experience lot of vibration, there could be a stirrer inside it separating oil from water. Hence the added reinforcement for the foundation.

DHURJATI SEN