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  1. bridgebuster

    "Bridge Engineering Vols. 1 & 2" by J.A.L. Waddell

    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...
  2. bridgebuster

    Field welding vs bolting to existing steel structures

    How old is very old? If you choose to weld- I prefer bolts- you might want to consider taking a coupon and testing it to ensure it’s weldable.
  3. bridgebuster

    Min free distance between girder and wall

    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"...
  4. bridgebuster

    Min free distance between girder and wall

    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.
  5. bridgebuster

    Truck loading with lane load

    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...
  6. bridgebuster

    Semi-integral Abutment Design

    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.
  7. bridgebuster

    Semi-integral Abutment Design

    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...
  8. bridgebuster

    Semi-integral Abutment Design

    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...
  9. bridgebuster

    Cost estimating software recommendation.

    Our estimating department also uses HCSS.
  10. bridgebuster

    Temporary Fencing Requirements

    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.
  11. bridgebuster

    Seismic Design for Stone Blocks

    This is drawing showing the anchoragehttps://files.engineering.com/getfile.aspx?folder=d5726a61-c906-474b-ab8d-3bb4342bf8cf&file=BPU_Drawing.pdf
  12. bridgebuster

    Seismic Design for Stone Blocks

    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
  13. bridgebuster

    AASHTO LRFD Bridge Design Software

    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.
  14. bridgebuster

    Girder bearing pad replacement

    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...
  15. bridgebuster

    Light pole mounted on traffic barrier

    BridgeSmith - we did precast on a job. The precaster called before he started the shop drawings; a few tweaks here and there; things went well.
  16. bridgebuster

    Light pole mounted on traffic barrier

    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
  17. bridgebuster

    Mill reports for redesign

    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.
  18. bridgebuster

    Thank God for Sparkies

    I'm glad you're on the mend dik. All the best for a full recovery.
  19. bridgebuster

    Cracks on pier cap

    I agree with Bridgesmith. In the 1983 AASHTO, the shear values were lowered quite a bit. Also, the photo doesn't match the drawing. Is there an expansion joint present?
  20. bridgebuster

    Steel Truss Bridge, Stringer Repair Detail

    SRE - no offense taken. I respect your opinions.
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