rolled beam splice

By bags1235 Date 11-02-2007 11:50

I have a two-span bridge beam in which I have a shop splice specified between two different sized rolled beam member (w-shapes). I have received a fabricator question asking how is this splice to be made? I responded that is shall be a shop cjp groove weld, welded, prepared, finished and tested in conformance with AWS Bridge welding code which seems very fundamental to me, but am I missing something? Are there known difficulties of making this type of shop weld between two different rolled beam member sizes?

By jwright650 (*****)

Date 11-02-2007 12:44

Can you provide the W-sections that you have proposed in this situation? Also if they are different depth sections, how do you want them to fit this up and welded, flush top with the top flanges aligned flush?, if so how much out of alignment are the botton flanges? Will you require the fabricator to abide by the 2.5:1 slope in regards to the mis-match in that joint?....As a fabricator, I can think of a zillion more questions if that was all the info someone supplied me with.....so....
Supply enough info and direction for a 3rd grader to clearly understand what is required, and you can't go wrong...Haha, that is what my ole chief draftsman used to tell us up and coming detailers when I started out in the drawing room many moons ago.

By bags1235 Date 11-02-2007 13:56

There are actually two different bridges involved with the following sections:

splice W920x342 to W920x417
and
splice W920x368 to W920x449

The members shall be spliced such that the web centerlines align.

By jwright650 (*****)

Date 11-02-2007 18:21 Edited 11-02-2007 18:24

Ok, You've thrown me a curve....Are these older W36" sections? I ask this because they don't convert to any W36" shape that I see in the AISC's 13th edition of the Steel Construction Manual.

Here are some WF Sections that are close to what you quoted:

W920x342 [W36x231] to W920x417 [W36x282]
....this combo has a 5/8" mis-match in depth.(might present some fit-up challenges at the bottom flanges) ...if the top flanges are required to be top flush.
Flanges only have an 1/8" difference in width(no problem there)
Flange thickness has a mis-match of 1 1/4" vs 1 9/16"(which would require some creative stringer stacking, but can be accomplished)
Webs ¾" vs 7/8"

The other splice is W920x368 [W36x247] to W920x449 [W36x302]...this combo has a ¾" mis-match in depth(again same, scenario at the bottom flanges if top flush is required)
Flanges have an 1/8" difference in width(no problem there)
Flange thickness has a mis-match of 1 3/8" vs 1 11/16"(again requiring some creative welding to make a nice transition)
Webs 7/8 vs 1"

Sounds doable.

edit: Just remember to keep the thickness transitions at 2.5:1 or less like D1.1:2006 suggests(paragraph 2.25)(Fig 2.2)