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  1. w12x26

    Brick Pier - f'm? Renovation/Addition in NYC

    I have not touched brick design in years but I have done a few rehab jobs in NYC and if I recall correclty, for a sound looking brick strucure I used to use a value of 1,200 to 1,500 psi for f'm. Try to get the applicable standards from the Masonry Institute??? (don't quite remember the name)...
  2. w12x26

    Sports Facility Structural Fee

    .25 to .5 of the construction cost is about average. I am not sure about the 11% of the architect's fee. 11% would be great. My bids are based on an estimate on how long it would take to do the work based on an hourly rate and about a 10% contingency depending on the client.
  3. w12x26

    CMU Wall Repair

    I assumed that foundation problems were a given and that they were verified. Now if there is no indication of settlement or foundation failure then I would address the roof framing. Are there ceiling joists or is the roof cathedral ceiling? the cracks could be induced by the lateral thrust at...
  4. w12x26

    A tricky question

    The system from a structural analysis point of view is stable but from a design view it is unstable because of the material and section properties. I would have gone through the determination of the reactions and loads in the strut and then the deflection before realizing it is unstable. It is...
  5. w12x26

    CMU Wall Repair

    This seems to be a differential settlement problem. Repairing the crack as suggested by Ron would be enough. You need to address what is causing parts of the footing to settle. This is most likely due to an improper or missing drainage system. As far as repairing the foundation you can either...
  6. w12x26

    Load testing of concrete structures

    BAretired, ACI 318, Chapter 20 also recommends the test load to remain in place for 24 hours which I am using for this exercise.
  7. w12x26

    Load testing of concrete structures

    Ron, I checked ACI 318 and the procedure was very detailed. It's been years since I deal with a concrete structure. Your tip was very helpful. Thanks.
  8. w12x26

    Cantilevered Beam Backspan- Unbraced Beam Length

    I am curious to see the load diagram for this problem. Obviously this a building structure and I really do not understand the relatively high loads.
  9. w12x26

    Cantilevered Beam Backspan- Unbraced Beam Length

    StructuralEIT, I used 36ksi steel and that may be the reason the beam did not figure.
  10. w12x26

    Cantilevered Beam Backspan- Unbraced Beam Length

    I ran a quick calculation on Enercalc and found the beam to be overstressed even for the fully braced compression flange condition. I may be missing something then. This was a pure ASD check and I am not sure I want to introduce plastic design into this exercise. I also usually design for...
  11. w12x26

    Load testing of concrete structures

    If you can give the name of the reference and relevant section it would then be very helpful.
  12. w12x26

    Cantilevered Beam Backspan- Unbraced Beam Length

    The 7' 6" cantilever is most likely an architectural requirement. I do not think adding a beam at the inflection point and end of cantilever would make any difference. Which inflection point would consider? the one under the dead load, live load or combined? If this were an actual project, I...
  13. w12x26

    Load testing of concrete structures

    It a good point you're introducing the time factor. One of the ASTM standards (static load testing of structures) specify that the load is to be applied for 5 minutes. What is the basis for the 24 hours requirement? I will check the ACI document to see if this is also addressed. Thanks.
  14. w12x26

    Load testing of concrete structures

    I will do that. Thanks for the help.
  15. w12x26

    Cantilevered Beam Backspan- Unbraced Beam Length

    You design both beams for the 815'-k moment and you need to consider the full 27'-6" length as unbraced unless you have other secondary filler beams which would physically brace the beam. If the cantiliver beam is a separate beam then the unbraced length would be the 7'6" length. In this...
  16. w12x26

    Load testing of concrete structures

    Are there any guidelines on what loads to use when load testing a concrete beams (post-tensioned beam). I am inclined to use the factored design loads. Something tells me I should use the service loads (unfactored loads) and somehow I also feel I should even increase the factored loads further...
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