Anchor Bolts Installed Too Short 6

[iv63]

1½”Ø anchor bolts have been installed too short (top of anchor bolt is about ¼” below of top of hex nut). Is it acceptable to use jam nut instead of hex nut? Since height of jam nut is two times smaller than hex nut can the strength of jam nut be estimated one half of the strength of hex nut? If strength of jam nut is not adequate to resist design tension in anchor bolt would welding the jam nut to the anchor bolt be acceptable? Thank you for your help. iv

 

[dik]

If they are 1-1/2" bolts, then they are probably designed for tension and jam nuts are likely too small.

Are the anchor rods weldable?

Dik

 

[rowingengineer]

what grade are the anchor bolts. I would suggest an full strength extension piece should be considered if possible.

http://www.nceng.com.au/

"A safe structure will be the one whose weakest link is never overloaded by the greatest force to which the structure is subjected” Petroski 1992

 

[Elite7]

Chip off pedestal to expose the anchor bolts. Install sleeve on the end of each anchor bolt, and thread on new threaded bars on top. Cast additional height of pedestal so as to cover the threaded sleeves and leave the new threaded bars exposed as the new ends of the anchor bolts. The steel column sitting on top of the pedestal will have to be shortened to suit.

 

[WillisV]

Use elocone nuts. This is what they are made for. Work great.

http://www.canam-steeljoists.ws/

http://www/v4/epublica.nsf/va_download/2C3C81683453B3C08525796B004D90FB/$File/eElocone.pdf

 

[vthomidis]

I think WillisV has your answer.....

Elite7, your proposal is quite sound but i think rather hard to
apply - it comes close to designing a new building...

 

[fegenbush]

The AISC Field Fixes guide recommends using a coupling to extend the anchor bolt and building up an anchor chair to make up the space that the coupling requires. This may or may not be acceptable to your design or aesthetic preferences.

 

[iv63]

WillisV:
Thank you very much for the excellent link. I will recommend these special elongated nuts.
iv

 

[ToadJones]

Might take some hole reaming to get the elongated nuts to fit if the bolt pattern isnt perfect and the holes aren't over-sized enough, but that's easy compared to the rest of the alternatives.
Nice reference Willis.

 

[rowingengineer]

Nice reference Willis, this is the best solution.

http://www.nceng.com.au/

"A safe structure will be the one whose weakest link is never overloaded by the greatest force to which the structure is subjected” Petroski 1992