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Recent content by DTGT2002

  1. DTGT2002

    Outrigger Platform

    For our internally generated details, we resolve the loads through the force couple with uplift at the "hold down reaction" (resisted through a minimum of two shores sized for one redundant to the other, with the innermost reaction location being used to size the shores) and the loading at edge...
  2. DTGT2002

    Shoring required for topping slab?

    It's been said a number of times, but this topping slab is explicitly noted with unit weight assumptions and maximum depth in the structural drawings? If yes, I agree that there is nothing to be concerned with from a loading point of view and your 100 psf live load rating exceeds the generally...
  3. DTGT2002

    Shoring Design - Connecting Props (post shores) to Girders (aluminum or wood beams)

    In the reshoring shown above, it is entirely possible a piece of spring steel is in place on top of the props. But even without such, the prop would need to rack some amount to fall free. The wide baseplate of the props help this more than you might see with a wood shore.. We often install a...
  4. DTGT2002

    Hard Rock Hotel under construction in New Orleans collapses...

    We should be careful here in a distinction between references that are made part of a specification by incorporation by reference versus those that are referenced in commentary or other non-mandatory means. I was not claiming that any and all references are somehow enforceable simply by...
  5. DTGT2002

    Hard Rock Hotel under construction in New Orleans collapses...

    Saying 347 is not applicable is not correct. SDI-C1.0 references ACI 318, which references ACI 301 which references ACI 347 to give the designer more information regarding the behavior of formwork, which includes shoring and reshoring. I have not yet found an SDI reference that provides insight...
  6. DTGT2002

    Safety Factors - outrigger platform design

    I'd say JStephen is right on. The outrigger platform itself when locked into the structure is a form of scaffolding as outlined in OSHA 1926 and would be expected to maintain a 4:1 FOS against failure. When rigged for flying, the anchor components engaged for lifting would be looked at under...
  7. DTGT2002

    Hoist Backpropping. Overdesign??

    I've never seen loads of that magnitude assumed at ALL floors before. Perhaps there is an opportunity to seek clarification on if the load is applied at all floors simultaneously or if they are trying to convey that it could occur at any given level. I think you could really justify engaging a...
  8. DTGT2002

    Construction Guardrail

    And do note, you are guarding against failure - no FOS noted. That said, we have not been able to resolve the figure 4 style brackets either. There may have been prescriptive guidance giving construction criteria at some point. If so, I don't have it. That said, one typically sees plywood or...
  9. DTGT2002

    beam to support weight of boat

    https://www.aluma.com/us/products/formwork_shoring/shoring/aluminum_joists_and_stringers You would want the 7.5" Aluma Stringer if you are pursuing the formwork beam route, nominally twice the capacity of the 6.5" Aluma Beam. The FOS related to their noted nominal capacity is typically 2.2:1...
  10. DTGT2002

    TOWER CRANE FOUNDATION DESIGN

    While the rental company or certainly the manufacturer had best be able to provide the data you need, perhaps there is an issue with your form of communication. I've not recently had to send a letter by mail for info, but its not unheard of. That said, give these guys a call. Yes, you are...
  11. DTGT2002

    plywood two way action

    I think we are a bit lost here - as noted above, we have not touched on the support conditions for the plywood - that is what will determine its bending behavior. If you primary concern is the potential for the individual blocking members to act as concentrated loads and potentially transfer...
  12. DTGT2002

    Sacrificial Wood Concrete Forms - Good or Bad Idea?

    Going back to your questions, wood is typically not abandoned in place for forms due to cost of lost material, risk of leaving a combustible material in a space, risk of termites and risks associated with the breakdown of said material in the work. If you are building a supporting wall at the...
  13. DTGT2002

    Sacrificial Wood Concrete Forms - Good or Bad Idea?

    What is supporting the perimeter? A wall? Can you leave one of the short ends open to strip the material? Its just crawlspace formwork at that point - but could have confined space concerns.
  14. DTGT2002

    Waterproofing at Form Ties in Concrete Walls

    There are also tapered ties used in heavier form construction that leave a smooth, but tapered hole that may be patched back in a number of ways, that do not leave a remnant of the tie in the work. I would hazard to say that in many cases, typical construction methods for structures would...
  15. DTGT2002

    Formwork Camber for Flat Slabs

    I would agree that a target camber that small would be difficult to appreciate (and frankly measure!). But I have seen 1/2" listed in specifications a time or two. On one hand, it can help someone think about a potential issue and trend towards the best result. Or it can confuse them.

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