Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Re: Structural steel--isolated joints

[Subject Prev][Subject Next][Thread Prev][Thread Next]
"I'd look at the whole system including a dynamic analysis"

agreed


"I'll risk raining on the parade and say that making that connection any
more flexible is just going to make the problem worse. "

How so?

We need the lateral support to resist the crane thrust perpendicular to the
crane rail. Do we need it for the vibrations?

You are right that the upper plate was added recently because the crane rail
was leveled. That is why there is the big gap in the bolted connection of
the lower plate. It is not clear if the cracks were already in the column
when the leveling was done and the upper plate added.

----- Original Message ----- 
From: "Christopher Wright" <chrisw(--nospam--at)skypoint.com>
To: "SEAOC Newsletter" <seaint(--nospam--at)seaint.org>
Sent: Tuesday, August 10, 2004 11:12 PM
Subject: Re: Structural steel--isolated joints


> >I'd agree, however the attachment is only a foot or  so above the columns
> >attachment to the primary crane support bent (two 10"x .25 wall pipes
laced
> >together)
> I'll stick to my guns after seeing the crack at the connection. This
> isn't anything like a typical crane rail connection. If this were my
> problem I'd look at the whole system including a dynamic analysis. I
> think the lateral loading was underestimated. You can probably make a
> pretty good estimate of the dynamic amplification as arising from a
> suddenly imposed displacement of the scale of the misalignment of the
> rails.
>
> If I'm not seeing things, it looks like someone tried weld repairs to the
> connector plates. I can't remember a situation like this where weld
> repairs did anything but make it worse.
>
> I'll risk raining on the parade and say that making that connection any
> more flexible is just going to make the problem worse.
>
> Christopher Wright P.E.    |"They couldn't hit an elephant at
> chrisw(--nospam--at)skypoint.com        | this distance"   (last words of Gen.
> ___________________________| John Sedgwick, Spotsylvania 1864)
> http://www.skypoint.com/~chrisw
>
>
>
> ******* ****** ******* ******** ******* ******* ******* ***
> *   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
> *
> *   This email was sent to you via Structural Engineers
> *   Association of Southern California (SEAOSC) server. To
> *   subscribe (no fee) or UnSubscribe, please go to:
> *
> *   http://www.seaint.org/sealist1.asp
> *
> *   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you
> *   send to the list is public domain and may be re-posted
> *   without your permission. Make sure you visit our web
> *   site at: http://www.seaint.org
> ******* ****** ****** ****** ******* ****** ****** ********
>



******* ****** ******* ******** ******* ******* ******* ***
*   Read list FAQ at: http://www.seaint.org/list_FAQ.asp
* 
*   This email was sent to you via Structural Engineers 
*   Association of Southern California (SEAOSC) server. To 
*   subscribe (no fee) or UnSubscribe, please go to:
*
*   http://www.seaint.org/sealist1.asp
*
*   Questions to seaint-ad(--nospam--at)seaint.org. Remember, any email you 
*   send to the list is public domain and may be re-posted 
*   without your permission. Make sure you visit our web 
*   site at: http://www.seaint.org 
******* ****** ****** ****** ******* ****** ****** ********