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Old 2nd September 2019
  #16
Lives for gear
 

Quote:
Originally Posted by Northward View Post
It's not because a beam can withstand such loads that the whole building can. In most our non-ground floor (industrial) projects, the structural issues did not come from the local floor beams but from the girders, load bearing walls and/or foundations that could not sustain such cascaded loads.
+1
In addition, and I'm not sure what the seismic situation is in Melbourne, but where I live (Chile - earthquake capital of the world) you would never get a building permit for something that involves adding many thousands of kilograms of mass concentrated at the top of a tall building, without getting approval from a seismic engineer as well as a structural engineer. All that extra mass up there in an earthquake, even a relatively small one, could do serious damage to the rest of the structure. A floated floor with dozens of tons of mass resting on springs, is going to be slamming around all over the place in a quake if the frequency is right. Most earthquake vibration frequencies are well below the audio spectrum... often measured in single digits ... perhaps even around what the tuned resonant frequency of the floating system would be. I haven't heard anyone else mention seismic snubbers for this potential build...

Melbourne had a 5.2 quake not that long ago... and has had quite a few 4.x quakes over the last 20 years or so...

- Stuart -