If you work on older bridges the ancient texts come in handy, by shedding light on long list terms, understanding why certain things were done, etc. A few years ago I did a superstructure replacement of a 2 span bridge designed in 1940, the pier design was exactly what Waddell recommended. In...
I'm not aware of any AASHTO provisions. On new NYSDOT bridges, centerline of bearing to face of backwall is usually 1-3" or 1'-6". The girder standards call for the centerline of bearing to be 8" from the end of the girder and the deck standards call for the deck to overhang end of girder by 6"...
If you're designing for particular DOT check their standards. Yes, the distance from the end of the girder should be larger than the displacement plus some fat.
A 20T truck is H20, two axels spaced at 14;'. The closest recognized legal load to a tandem 20T truck is AASHTO Type 3, which is 25T. The first axle is 16k, the next axle15' away is 17k, the third axle is also 17k, & 4 feet away. You could use that configuration and proportion the loads down to...
Correct, but it assumes the integral abutment is a free standing column, which seems overly conservative to me. Meanwhile, the longitudinal deflection for the bridge as currently designed is less than an inch.
Thanks for the replies; as I said above I needed a sanity check or perhaps a sounding board. My initial response to him was "B@!!$#|+" There's enough passive pressure to resist 80% of the seismic force and I wasn't even considering shear resistance of the elastomeric bearings. Then he proceeded...
We have a project under construction. 175' long integral abutment bridge. Due to a number of issues related to pile driving at one abutment, the owner asked about changing one abutment to semi-integral and using drilled-in micropiles. The designer said it was impossible because under an extreme...
We have a project with templates fence. It’s designed for wind per ASCE 7-22. It’s in an area no accessible to the public. Depending on your situation, you could try a load case with an eccentric 250 pound load to simulate a person climbing on it.
see attached calculations. it's from a project we did 20 years ago. Stone veneer on a retaining wall in NYC.https://files.engineering.com/getfile.aspx?folder=cc279838-4a52-468d-bdd6-e69543c39e47&file=Panel_Attachment_Calculations.pdf
CSIBridge has become very popular with our staff. Several of our engineers are being trained in Open Bridge. We've been using STAAD, Leap. and MDX for many years. We haven't used Merlin Dash & DESCUS for about 20 years; I liked these better than MDX. I've also used LRFD Simon.
Are you a contractor bidding on the work? On the design side with this type of work, the engineer provides a bearing design. On NYSDOT projects, the jacking system and shoring is designed by the contractor, in accordance with specification requirements.
The cost per bearing would be the cost to...
See attached; we do this all the time. I've never seen a barrier without hairline cracks, though yours look more significant.https://files.engineering.com/getfile.aspx?folder=931af9a0-4906-4ab1-a896-afa1c6f18217&file=light_blister.pdf
I used mill certs to reanalyze a temporary railroad structure. I inherited a project during construction and stumbled upon a major design error. I went the mill certs route and fortunately the yield strength was much higher.
