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  1. BridgeNerdGuy

    Girder Tensile Stress in Precompressed Tensile Zone At Service III?

    I must have found this topic more interesting than the other bridge engineers around here. What intrigues me the most is that limiting designers to ZERO tensile stress at SERVICE III would often result in deeper girders, additional girders lines, and an increased prestressing steel quantity...
  2. BridgeNerdGuy

    Optimum span length

    AASHTO [5.12.3.3.4] allows for the calculation of restraint moments (caused by deck shrinkage and restrained girder rotations) to be waived when a positive moment connection per [5.12.3.3.9] is provided (usually by simply extending prestressing strands into diaphragm) and requiring the girders...
  3. BridgeNerdGuy

    Optimum span length

    Interesting. I think these comments are regionally motivated or influenced. Simple span made continuous for live load is a bread and butter preferred structure type for highway bridges in my market. The design tasks aren't too hard either, anyone capable of designing a steel bridge can easily...
  4. BridgeNerdGuy

    Circular Concrete Columns

    This is ACI 318 based but shows the physics at play quite well. I'm unfamiliar with the Canadian code differences but since this is a full example calc maybe you can find the differences and set up your own Canadian version in excel. I use this method in excel and iterate over the neutral axis...
  5. BridgeNerdGuy

    Sesimic Analysis for Single Span Bridges

    I would not solely use the AASHTO LRFD Bridge Design Specifications for the design of this structure. The code is written for vehicular traffic bridges which have structural properties and behavior much different than this castellated beam. Section [1.1] SCOPE OF SPECIFICATIONS states "The...
  6. BridgeNerdGuy

    Is this deadman just a pure oncrete without reinforcements?

    You told us you were designing this bridge in other threads. You've asked for design resources, posted pictures of your structural model, and have asked many other very basic and concerning questions. If you are actually designing this you need to be honest with yourself and the capabilities of...
  7. BridgeNerdGuy

    AASHTO LRFD Table A4-1 Live Load Significantly Low

    If you just solve a continuous beam loaded with the Design Truck and compare moments to the table you will notice the table values are much lower. Why? You need to determine how much of the deck resists this load, Your value needs to be divided by the strip width in 4.6.2.1. Table A4-1 reports...
  8. BridgeNerdGuy

    Concrete column design: Equation

    I just want to second the resource dik shared. I used an earlier version of that same file to set up my circular reinforced concrete column excel sheet that generates the interaction diagrams. I've had great success comparing my excel diagrams/capacities/results to software output for bridge...
  9. BridgeNerdGuy

    Pedestrian Bridge Resources

    Not an addendum but AASHTO publishes the LRFD Guide Specifications for the Design of Pedestrian Bridges. The free table of contents can be found here: https://store.transportation.org/Item/PublicationDetail?ID=1552
  10. BridgeNerdGuy

    Girder Tensile Stress in Precompressed Tensile Zone At Service III?

    The WSDOT Bridge Design manual [5.2.1.C] does not allow tension in bridge girders at the service III limit state, i.e. final stresses after losses with all permanent loads plus live load. AASHTO LRFD 9th edition Table [T5.9.2.3.2b-1] allows some tension in the precompressed tensile zone assuming...
  11. BridgeNerdGuy

    NCEES Structural PE (SE) Examination - Refresher/Review Course Recommendations?

    I think "the kinks" come from moving to a closed book format regarding references that are not codes, transitioning the long form essay into a multiple choice format, and moving from 2 day 16 hour to 5 each 4 hour sessions. The "regular" PE exams were a much less drastic change IMO...take the...
  12. BridgeNerdGuy

    NCEES Structural PE (SE) Examination - Refresher/Review Course Recommendations?

    I took the exam in 2022 & April 2023. From reddit and engineer boards it seems 200-300 hours per exam is the going rate these days as the exam only gets broader and codes only get larger. My time includes 1 failed attempt at lateral; with 30 days to go I realized passing the lateral PM was a...
  13. BridgeNerdGuy

    Post Tension I girder failing concrete stress compression

    Transfer typically refers to the stage immediately after stressing but before time dependent losses can occur. At this point you can add steel to the top of your section, minimize the eccentricity of your strands, reduce strand quantity, or change sections to increase the denominators recalling...
  14. BridgeNerdGuy

    NCEES Structural PE (SE) Examination - Refresher/Review Course Recommendations?

    Drift, the exam is moving to full CBT after the October 2023 cycle, including the afternoon. The exam will now be 5 4 hour sessions instead of 2 8 hour exams.
  15. BridgeNerdGuy

    NCEES Structural PE (SE) Examination - Refresher/Review Course Recommendations?

    The SE was a whole different animal than the PE with structural depth IMO; significantly harder, more in depth, and time was much more of a concern. There are some unicorns out there who have enough professional experience they could pass without extensive studying but for the vast majority of...
  16. BridgeNerdGuy

    NCEES Structural PE (SE) Examination - Refresher/Review Course Recommendations?

    It is Dr. Foued Zayati. Picture this, we've all heard someone ask a question in a professional or academic setting where the instant response of half the room is "oof, you should really know that by now, you're destined to fail if you don't get this already." I found it refreshing and almost...
  17. BridgeNerdGuy

    Steel Decking over CHS beam

    This is an interesting and goofy structure. If I'm interpreting everything correctly this looks like a summer intern project gone wrong! My first concern is for the web crippling of the metal deck panels due top lack of bearing area. The grid of pipes is already fully constructed and now you...
  18. BridgeNerdGuy

    Wind Load Factor for Construction Loading

    ^ Revised link to the TOC which can be accessed for free: https://store.transportation.org/Item/PublicationDetail?ID=3728
  19. BridgeNerdGuy

    NCEES Structural PE (SE) Examination - Refresher/Review Course Recommendations?

    First and foremost, be aware the SE is transitioning to a computer based testing after the October 2023 cycle so the opinions you collect will be from people who studied for and took a different format of the exam. I feel for people testing in 2024/2025; they're literal guinea pigs for an...
  20. BridgeNerdGuy

    Flat slab bridge thickness

    @BridgeSmith I agree with your terminology distinction here

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