Precast beam to bridge abutment connection

[TehMightyEngineer]

Does anyone have any good references on the detailing or design of precast tee beam girders to abutment connection? I may have a single span prestressed girder project project coming up where we'll be responsible for this connection detail and I can't seem to find a good reference on the typical details used.

Seems like steel girders are much more common when it comes to examples of this connection. Not something I'd like to reinvent the wheel on if I don't have to.

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

http://www.americanconcrete.com

 

[SlideRuleEra]

TME - If seismic loading is not a problem, one way that I have seen (in the 1970's) is to just set the girders on bearing pads (neoprene rubber) - no anchor bolts or other connections. See the following CalTans publication for some ideas:
CalTrans Bridge Design Practice - Precast Pretensioned Concrete Girders

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[TehMightyEngineer]

No seismic analysis required (other than minimum seat width), only significant load on the connection will be breaking forces I suspect. I was wondering if it was typical to just drop them onto neoprene bearing pads as that's about the only detail I could find. That's what we've done with precast slab bridges but those usually have rebar dowels into the abutments. I'll take a look through that CalTrans reference, I've probably looked at it a few years ago but forgot I had it in my pdf library.

Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

http://www.americanconcrete.com

 

[SlideRuleEra]

Just sit the girders on the neoprene bearing pads, no dowels, no bolts... just friction. Also, the bearing pads just sit on the caps, nothing holding them down either. The first time I saw this done was on the upper outer banks of North Carolina.

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[BridgeEI]

Our local DOT quit using double tee's a long time ago but if I recall correctly, I believe they had an encased plate in the bottom of the tee and this was welded to the anchor plate on the elastomeric pad. I'm not sure if the details exist but I'll try to dig them up.

I lied....it exists and is alive and well.

http://www.okladot.state.ok.us/bridge/1999-cb-lfd/brd_std_1999-lfd-cb-e-04.pdf

 

[MotorCity]

I am not a bridge guy, but could you use whatever detail they use in parking garages when the tees are supported by L shaped beams or inverted tee beams? Most of the tee beams I have seen have pretty thin webs and flanges, doesn't seem like there is a whole lot of anything to grab onto for a connection.

 

[TehMightyEngineer]

I lied....it exists and is alive and well.

Nice detail, that's exactly what I was hoping to find. Our DOT also has gone away from double tees but this is a non-DOT job, and as we don't own the forms for NEXT beams or bulb tees making a down and dirty tee or double tee girder in our stressing bed seemed like the easiest way to go. Adding a weld plate wouldn't be hard at all and I think the contractor might actually like it.

I also just rediscovered this website and will have to go through it again for useful nuggets of info: [URL unfurl="true"]https://www.fhwa.dot.gov/bridge/prefab/if09010/02c.cfm#d4[/url]

I am not a bridge guy, but could you use whatever detail they use in parking garages when the tees are supported by L shaped beams or inverted tee beams?

Not a bad thought at all. The precast double tees for buildings and parking garages love their embedded weld plates connection which fits with what BridgeEI was thinking above. Those don't usually have an elastomeric pad but I think that's just the inherent differences between a bridge girder and a garage floor beam.


Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries

http://www.americanconcrete.com