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Recent content by tmac7285

  1. tmac7285

    AS3600 2018 Amendment 2

    Thanks for letting us know guys. I'm looking forward to the commentary!
  2. tmac7285

    AS 1170.4 Clause 1.1 - Building with a Period Greater than 5s

    saplanti, I'm in Australia and what you are suggesting is just not common practice and no client here would know what response spectra is, let alone have that kind of specific site information. EQ rarely governs the design for taller buildings here, due to the lower seismicity acknowledged in...
  3. tmac7285

    AS 1170.4 Clause 1.1 - Building with a Period Greater than 5s

    mrlm, as Retrograde suggests these are typically wind dominated buildings (not that we can ignore EQ, particularly with the new code). There have been a couple of buildings pass through our office in the 130m-160m range that have stability systems that are less stiff than what the typical rules...
  4. tmac7285

    AS 1170.4 Clause 1.1 - Building with a Period Greater than 5s

    Thanks Agent666. 1. There is a minimum base shear when considering using etabs periods. The minimum is 70% of the shear that the code produces. However, I believe the clause relating to minimum base shear for a modal analysis has been subsequently removed, though I think there are at least some...
  5. tmac7285

    AS 1170.4 Clause 1.1 - Building with a Period Greater than 5s

    The 1170.4 clause 1.1 (g) states that buildings with a first mode period greater than 5 seconds is outside the scope of the standard. Where or whom are we supposed to go to for this approach? 1170.2 has a similar criterion and that the code based wind does not include any buildings with a...
  6. tmac7285

    Precast column offset issue

    Looks like a full transfer design, using whatever appropriate program you have available. You would have to carry out all the normal checks bending, shear, deflection etc. You would get a bit of a bonus for punching shear, given that you're partially bearing and inside the critical punching...
  7. tmac7285

    Approximate Method for Estimating Maximum Cross Wind Induced Hight Rise Acceleration

    phamEng is right, the AS1170.2 has a codified way to estimate the cross wind response for given building ratios (height, width and length). It's not super quick to calculate, but is really useful at a prelim stage. My experience is that the code is pretty conservative with its estimations; the...
  8. tmac7285

    Modelling Staircases in Softwares for Structural Analysis

    hardbutmild, I'm not sure I understand what you mean by the whole "stair area' being enclosed in an RC core. Do you mean that the stair is just internal to core? Why would this change anything? If you have a diagonal element, such as a stair or ramp, that is rigidly connected to a diaphragm at...
  9. tmac7285

    Modelling Staircases in Softwares for Structural Analysis

    It would depend on what you are trying to get from you analysis and how you plan to detail the element in question. Do you have a particular problem in mind? Can you ask a more experienced engineer in your office about it and what common practice is? If you are considering a lateral stability...
  10. tmac7285

    AS3600-2018 - Detailing for grouted ducts in precast walls

    I think that's an interesting question Liongalahad, and I think you're on the right track looking at the NZ commission document. It'd be worth looking at the NZ concrete code too. I was speaking to some of the Kiwi's in our office about this yesterday and they essentially said that after...
  11. tmac7285

    AS 11.5.2 b) - Plain concrete Walls on De or Ee Soil Classification

    rapt, Further to my other response above I've done a bit more reading and clause 11.2.1 specifically allows for clause 11.7.4 to override the requirements of clause 10.7.4, so the code explicitly allows for my previous assertion. captain slow, I agree it's worth seeing what the impact of...
  12. tmac7285

    AS 11.5.2 b) - Plain concrete Walls on De or Ee Soil Classification

    rapt, CL 11.7.4 is designing the wall as per chapter 10 column design, but allows for no ligatures, provided that the conditions are met (low stress, low reo, low concrete strength etc). I'm not trying to be facetious, but why would I think I can't do that if it is not precluded specifically...
  13. tmac7285

    AS 11.5.2 b) - Plain concrete Walls on De or Ee Soil Classification

    Thanks guys. QSSIN, I agree that with a small core, long blade elements will become a non-trivial part of the lateral stability system. I don't know exactly where the trivial vs non-trivial line lies, but in the building I am considering the blades will add <3% of stiffness to the cores...
  14. tmac7285

    AS3600 - 2018 Amendment 2 Draft

    Thanks IDS, all sorted now with that link!
  15. tmac7285

    AS 11.5.2 b) - Plain concrete Walls on De or Ee Soil Classification

    The relevant clause states: The simplified design methods for walls subject to vertical compression forces is b) not to be constructed on sites with soil classifications De or Ee, as defined in AS 1170.4, and where subject to earthquake design. Is this essentially saying that stability walls...

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