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  1. Bobby46

    AISC Table 1-1

    I was curious if anyone knows the reason that AISC Table 1-1 has multiple sections for an individual beam size. Is it to signify some strength difference or availability? For example: W36 are listed in two "groups". There is a grouping of W36x135 to W36x256 and a separate grouping for W36x231...
  2. Bobby46

    Allowable Lateral Deflection of Timber Piles

    I've seen plenty of timber piles that have a localized "sweep". This can look concerning when only the sweep is projecting out of the ground. It is entirely possible that pile is plumb below the ground surface It is also entirely possible that the other piles that appear plumb are not plumb...
  3. Bobby46

    Surcharge Loads from Building Next to SOE

    The AASHTO Guide Design Spec for Bridge Temporary Works also references the 1.5H:1V requirement in Section 4.3.3
  4. Bobby46

    Bridge pier footing with sheet piling

    You're definitely right. I just assumed it was an integral abutment bridge based on the title of the book. Back to the drawing board... Edit: Picture was from the next bridge downstream
  5. Bobby46

    Non-expansive clays?

    "But what about the rest of the clays? Do they not expand and contract at all? I imagine there is a spectrum."
  6. Bobby46

    Non-expansive clays?

    Presumpscot and Boston Blue are the two big clay formations we see. They are essentially the same thing. Deep foundations, ground improvement, and preloading/wick drains are the common ways around it. Deep foundations and ground improvement send the building weight to rock so the clay doesn't...
  7. Bobby46

    Non-expansive clays?

    My area doesn't really have an issue of expansive clays. We have soft, sensitive clays. When disturbed they lose all the shear strength and turn into soup. Clay in this area is generally saturated at all times, so it does not see the swelling that a dry clay experiences.
  8. Bobby46

    Bridge pier footing with sheet piling

    For some reason I cant see page 4 and 5 now either. It only had a paragraph or two on this bridge. I think it mentioned that this bridge was one of the first multi span bridges that didnt use rivets to connect girders. I'm not an expert, but i think the general concept is you have a flexible...
  9. Bobby46

    Bridge pier footing with sheet piling

    Looks like this is one of the first integral abutment bridges with a "flexible foundation". Info on pages 4 and 5...
  10. Bobby46

    Driven Pile Downward Capacity

    You do not need to correct the units in the ENR formula. The formula has been simplified over the years. The top of the equation originally had a 12 in it to convert from feet to inches. There was a FOS of 6 on the bottom of the equation. These have been combined into a 2 (12 divided by 6). At...
  11. Bobby46

    Soldier Pile Timber Lagging Wall

    Check out ACI 229 Controlled Low Strength Materials. They have some sample mix designs from DOT's. You can find it for free on google.
  12. Bobby46

    AISC J10.4 Web Sidesway Buckling

    Thanks JAE. Thanks windlandv. I didn't realize there was a symbols section. I looked in the General Nomenclature section before the index, but I didn't see it listed.
  13. Bobby46

    AISC J10.4 Web Sidesway Buckling

    I'm doing some checks to size transverse web stiffeners for a wide flange beam. I was hoping to get some clarification on the web sidesway buckling check. Specifically, I am looking at Cr factor. AISC directs you to select a Cr factor based on the ratio 1.5Ma to My. I can't find a definition for...
  14. Bobby46

    Standard hooks on circular ties.

    CRSI has a good article on it in their Detailing Corner series. It is called RFIs on Circular Ties, Rotating Hooks, Staggered Lap Splices and Closure Strips. https://www.construccionenacero.com/sites/construccionenacero.com/files/u11/ci_31_detallado_del_acero_de_refuerzo.pdf
  15. Bobby46

    Flagpole calculation for guardrail

    Check out Precast Concrete Connections with Embedded Steel Members by Marcakis and Mitchell. It's from a PCI Journal July-August 1980 I can't find my copy online, but here is his thesis http://digitool.library.mcgill.ca/R/?func=dbin-jump-full&object_id=54736&local_base=GEN01-MCG02
  16. Bobby46

    Inclined Footing Load Factor Charts

    Does anyone know of a place where Meyerhof's charts for bearing capacity factors for footings with inclined/eccentric loads have been reproduced or scanned in high quality? I have a copy of his paper but the charts are about 1"x1" and it is difficult to read the labels. This is the paper I am...
  17. Bobby46

    Can Hydrostatic Force also Resist Applied Load?

    I agree if it is truly a sealed rigid structure. Then the net hydrostatic force is zero. I was thinking of it as an independent wall designed on a per foot basis.
  18. Bobby46

    Can Hydrostatic Force also Resist Applied Load?

    It sounds like your analogy is blurring the lines between buoyant concrete weight and passive water pressure. If you drive a sheetpile in the middle of a lake, it wont fall over due to water pressure until you pump water away from the passive side.
  19. Bobby46

    Three sided excavtion - again

    Put some corner braces in to put the side walls into passive. It will also give you extra normal force for friction.
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