Dear Boh Jaw Woei:
If your project is in Los Angeles, numerous requirements come into play.
Keeping up with them is challenging for both engineers and contractors alike.
Boh Jaw Woei wrote:
> 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'.
> -----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
> entirely different.
> If you have numerous damaged bolts due to welding (I cannot imagine
> welding nuts could be responsible for the described broken bolts!), I would
> curious to know whether the 'tack welding' was associated with correcting
> 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
> 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.