Connecting a Diaphragm to a Stringer Splice 1

[bridgebuster]

Happy Thanksgiving.

Does anyone know of a DOT that permits the connection of an intermediate diaphragm to a girderor stringer splice?

Someone in my office designed a three-span bridge, with a 30-degree skew; the stringers have four splices each. The intermediate diaphragms frame into the girders at a 90-degree angle. Unfortunately, he didn't show the splices on his framing plan and the detailer has noted 16 locations where the diaphragms are directly in line with the girder splices.

The bridge is owned by a municipality but they follow NYSDOT standards, which prohibits this type of connection. We can't move the splices because the fabricator has already cut the stringers.

The fabricator wants to connect the diaphragms at the splice; the owner doesn't care. I can detail a connection and I'm not concerned about fatigue because the bridge only carries non-commercial vehicles. It is designed for HS-25.

In my office the mangement wants me to find a standard that shows this is acceptable because we're deviating from the NYSDOT standards.

 

[MichSt]

I know in Michigan and Ohio, that detail wouldn't fly. I would stick to the standards and modify your framing plan as necessary.

 

[Qshake]

bridgebuster....

Sorry to hear about the predicament. Most DOT's that I know of in the midwest have older details for siuations just like yours. The norm is to use a bent plate bolted onto the splice which also connects the out of plane cross frame or diaphragm. While this may not be optimal, it's definitely doable.

Here is an example from Ohio, no doubt,....

http://spinternet.dot.state.oh.us/D...Superstructure Detail Beam Splices/SDBS16.pdf

But as I've said, it's a common detail for many older manuals and such.

Best of luck.

Regards,
Qshake

Eng-Tips Forums:Real Solutions for Real Problems Really Quick.

 

[bridgebuster]

Thanks very much Qshake. It's just what I needed.