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RE: Welding on bolts

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Steven, thanks for your advice.

1. I am also indeed very suprised that tack welding of nuts could lead to
the described damages. I bet the contractor has engaged some very
unqualified welders to do the job. 
2. It was quite clear on the site that the broken bolts and distorted nuts
were due to 'over welding'.
3. I don't think the contractor has the intention of enlarging/altering the
baseplate hole pattern. The design, by another engineer, seem alright.

In short, i think the problems arise because of the irresponsible contractor
and an ignorant 'welder'.

sgdon

-----Original Message-----
From: Steven A. [mailto:cratylus(--nospam--at)earthlink.net]
Sent: Tuesday, April 03, 2001 1:40 AM
To: seaint(--nospam--at)seaint.org
Subject: Re: Welding on bolts


     I had the impression that the connections you refereed to (in the
original message) dealt with a steel to steel assembly,
as opposed to column base plates. The inquiry spurred much e-mail debate
relative to high strength or slip-critical
bolting applications. It would appear that the the nature of the connection
is
entirely different.

     If you have numerous damaged bolts due to welding (I cannot imagine
tack
welding nuts could be responsible for the described broken bolts!), I would
be
curious to know whether the 'tack welding' was associated with correcting
slop

in the baseplate bolt holes. Further, if two of the of 6 bolts are broken,
could it have been purposely sheared off
because of a field problem or defective hole pattern in the fabricated
baseplate? The fact that all the nuts are "distorted"
suggests that problems arose in the field.

     Also, it sounds as if the "welding process", in combination with broken
bolts and distorted nuts, may be related to flame cutting to either remove
bolts or enlarge/alter the baseplate hole pattern.

     I would recommend caution in prescribing a method of repair before
taking
a closer look at what happened both in fabrication and erection.


     Steven A.




Boh Jaw Woei wrote:

> Now, on a base plate connection, 2 of the 6 botls are broken(due to the
> welding process) and almost all the nuts are 'distorted'. I am thinking of
> using hilti to installed 4 larger bolts to strengthen the base plate
> connection. Are there any other more efficient ways to compensate damges
> done to the base plate connection? thanks.
>
> sgdon
>
> -----Original Message-----
> From: Fountain Conner [mailto:fconner(--nospam--at)pcola.gulf.net]
> Sent: Friday, March 30, 2001 10:07 PM
> To: seaint(--nospam--at)seaint.org
> Subject: Re: Welding on bolts
>
> Along the same line...
>
> I work in an industry where the standard anchor bolt is A316 stainless
> steel.  How do you feel about crimping the threads each side of a nut
> that's embedded in the concrete for anchorage?
>
> Fountain E. Conner, P.E.
> Gulf Breeze, Fl. 32561
>
> P.S.  The wheel, huh?  Did you, perhaps, develop the triangular wheel?
> Y'know it has one less bump per revolution ;-)
>
> ----------
> > From: Sprague, Harold O. <SpragueHO(--nospam--at)bv.com>
> > To: 'seaint(--nospam--at)seaint.org'
> > Subject: RE: Welding on bolts
> > Date: Friday, March 30, 2001 9:26 AM
> >
> > Mechanical deformation of threads is very low tech.
>
> >
> > Regards,
> > Harold O. Sprague
>
> > inventor of the wheel,
>
> > etc.
>
>