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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
Thanks for letting us know rapt. I couldn't see anything on SAI global, and the Concrete Institute had a page noting that the draft was available but no links were provided. Is this available somewhere else for us to download and read?
human909/Agent666,
I agree with you and the general approach. The reason for my question is that several other engineers in my office don't see it this way. They want to avoid column cages in the walls wherever possible due to the increase in reo and difficulty to build. Between Cl 14.6.3 and...
The clause relating to confining a wall for concrete greater than 50MPa in strength is in the Earthquake section of the new concrete code. If I don't require 50MPa concrete for the earthquake design (and would then not need to confine the wall with fitments to this part of the code based...
This clause states that "For structural walls where f'c > 50MPa confinement of the wall core shall be provided throughout by fitments in accordance with Clause 14.5.4". Clause 14.5.4 then goes on to tell the designer what spacing of the fitments will be required.
I'm interested in understanding...
