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  1. Just Some Nerd

    Strut-Tie - Tie Development at Nodes (Starter Bars)

    Hmmm I'll retract my previous as a blanket statement. I do find it hard though to imagine footings that both a) require large tensile forces and b) have a shallow footing depth. I don't think that sticking larger starter bars are needed for this scenario either though, as the deeper footing will...
  2. Just Some Nerd

    Strut-Tie - Tie Development at Nodes (Starter Bars)

    I imagine the hinge can just end up forming slightly higher (where the starters stop, probably midway up a story)? Knowing that the connection to the footing is of a higher capacity than the wall itself seems like a positive thing when it comes to ductility.
  3. Just Some Nerd

    Strut-Tie - Tie Development at Nodes (Starter Bars)

    I wonder if we're going too far down a train of thought that doesn't matter all that much. NEHRP doc that Koot posted earlier implies a pretty simple way to resolve things: -If bars in col/wall above must be in tension, follow normal development rules for said bar to get the tensile capacity...
  4. Just Some Nerd

    Casting concrete directly to pile cap which has muddy water

    Whenever I go inspect some footings, even if the site is bone dry in the middle of the desert I'll still note to make sure the base is fully drained and cleaned out prior to pouring concrete. Muddy bars are also a pet peeve of mine.
  5. Just Some Nerd

    Strut-Tie - Tie Development at Nodes (Starter Bars)

    One way to resolve this is to apply the tension from the column at a node close to the top surface, and the portion in the slab be handled by shear reinforcement. It's more like the shear reinforcement is lapping with the column starters in that solution though as they're in a straight line. I...
  6. Just Some Nerd

    Do you think it is right to design it as a 150cmx150cm column and rod element?

    I'd just model it in ETABs as a column frame, you can even define it as a composite section directly. 1500x1500mm concrete column doesn't seem too outlandish for a 200 story building ---------------------------------------------------------------------- Why yes, I do in fact have no idea what...
  7. Just Some Nerd

    beam load off center

    Didn't quite comprehend in the initial posts that it was beams stacked on beams, you can imagine my surprise scrolling down and realising that the steel equivalent of balancing a house of cards is going on ---------------------------------------------------------------------- Why yes, I do in...
  8. Just Some Nerd

    Do you think it is right to design it as a 150cmx150cm column and rod element?

    Really hope they're steel columns and not concrete.... ---------------------------------------------------------------------- Why yes, I do in fact have no idea what I'm talking about
  9. Just Some Nerd

    Punching Shear at Varying Slab Thickness

    I'd be looking to rearrange columns / add additional ones to reduce the loads going into that 450 zone and make this situation a lot more favourable. Given a choice I'd rather avoid this situation entirely very early on in the coordination stages and have that 1150 zone extend fully over any...
  10. Just Some Nerd

    Horizontal Stiffener to increase beam shear capacity

    Looks like this thread has narrowed it down to a more likely intent. In typical sections/loading flanges aren't really contributing to vertical shear capacity, that was my unhelpful way of stating it. Seems like it must be a moment connection for the column whether the beam wants a moment...
  11. Just Some Nerd

    Horizontal Stiffener to increase beam shear capacity

    I imagine it adds to shear capacity in the same way that any flange does ---------------------------------------------------------------------- Why yes, I do in fact have no idea what I'm talking about
  12. Just Some Nerd

    Column strength for member loaded near the base.

    I wouldn't be assuming the fixity at the base, my line of thinking was designing the base connection for it explicitly. I'm generally a concrete kind of guy so I'm not actually sure that sort of fixity works with baseplates and watnot
  13. Just Some Nerd

    Column strength for member loaded near the base.

    I'd design it as a 1m tall column fixed at the base, no restraint at the top. The self weight of the column above 1 metre can be taken as an additional applied load at the 1 metre height. I've never actually had to deal with this scenario in my work so I wonder...
  14. Just Some Nerd

    Tourist submersible visiting the Titanic is missing Part 2

    Surely this picture is a joke??? ---------------------------------------------------------------------- Why yes, I do in fact have no idea what I'm talking about
  15. Just Some Nerd

    cracked stiffness?

    I'd also be destiffening the walls for out of plane moments (e.g 0.1) ---------------------------------------------------------------------- Why yes, I do in fact have no idea what I'm talking about
  16. Just Some Nerd

    AS 3600 Cl 10.8 Transmission of Axial Force through floor systems

    I wouldn't be designing this as a "transmission through" case, the load is being applied to the slab and the slab has to transfer the load to the column. You might be able to take the overlapping region as a a portion of the load transferring through and putting the remaining load to the...
  17. Just Some Nerd

    AS 3600 Cl 10.8 Transmission of Axial Force through floor systems

    I'm not fond of using the squash load for transmission through the slab. If the column above and the column below are both having to account a minimum moment, the section confined inside the slab should be transferring that minimum moment through...
  18. Just Some Nerd

    PT Edge Stressing on Exposed Slab and Construction Joint

    I take it there's at least some emphasis on "many years" because I haven't encountered them at all here (Sydney, mostly work on resi towers). There's almost no PT installers I'd consider competent these days ---------------------------------------------------------------------- Why yes, I do...
  19. Just Some Nerd

    PT Edge Stressing on Exposed Slab and Construction Joint

    Had this happen on a recent job, mid way through building we changed it all the edge stressing to pans because the builder/client was finding it unsightly on the lower levels. Finishing it over with render or similar before painting will often still be prone to cracking at the live ends. I...
  20. Just Some Nerd

    Stiffness modifiers in buildings where steel and reinforced concrete are combined.

    If my understanding of Greenalleycat's post is correct, I'd probably opt to apply ordinary modifiers to concrete with no modifiers to the steel, and multiply the output displacements. The inverse of a 0.8 stiffness modifier would be x1.25 I think, if I'm doing my math correctly...

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