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| Thread ID: 141816 | 2016-03-04 21:14:00 | Darwin Rules ! | Terry Porritt (14) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 1416897 | 2016-03-06 07:54:00 | Updated pictures and images from Stuff: www.stuff.co.nz I have seen old Pinus Radiata 6x4's fence posts do this, snap in a fairly even break, having virtually lost all flexibility and the natural graining turned to matchwood, lost most of the expected mass even though looking perfectly normal on the outside due to weathering and aging, these were 26 years old apparently. |
zqwerty (97) | ||
| 1416898 | 2016-03-06 08:54:00 | So you want the building code to double the safe working load of decks and balconies to take into account jumping up and down simultaneously? If you can not blame people for jumping on a balcony then our Western democracy is buggered. no. first thing is to find out exactly what happened. was there rot, was the timber the right size, the right timber, was it built right and was the design right. what the spec correct for the use. i would only expect the safe working load of decks to be increased if the spec is incorrect for the use. its a bit ridiculous having a 20 seater bus that is meant to only carry 8 people and breaks in half when you put 20 in it. you wouldn't do that for a bus, why would you do it for a building? |
tweak'e (69) | ||
| 1416899 | 2016-03-06 09:10:00 | Even if the resonant frequency was different to the jumping frequency, the deck was still subjected to a forced vibration which would need to be analysed properly, and the maximum deflections and bending moments determined. Your crude jumping analogy does yield any useful quantitative information. I was not attempting to quantify anything. Just expressing my opinion that weight and leverage was all that was required to break the beams and vibration probably wasn't the cause. Not saying it couldn't be a factor, just that personally I suspect it's not a significant one. Also I seriously doubt those balconies were designed with more than 4-8 people in mind, certainly not 20 or so jumping up and down. They are very small balconies after all, the pictures don't even look like you could fit any furniture on them. |
dugimodo (138) | ||
| 1416900 | 2016-03-06 09:16:00 | From the last link I posted: 'Cutler told Stuff on Saturday the tenants were "explicitly told" only eight people were allowed on the balcony. "The balconies are not built for 20 people."' |
zqwerty (97) | ||
| 1416901 | 2016-03-06 10:14:00 | From the last link I posted: 'Cutler told Stuff on Saturday the tenants were "explicitly told" only eight people were allowed on the balcony. "The balconies are not built for 20 people."' my view is thats the problem right there. the balcony is not built for 20 people but can fit 20 people on it. |
tweak'e (69) | ||
| 1416902 | 2016-03-06 18:19:00 | On RNZ news this morning it was said that video taken at the time and given to police, but not publicly released, shows that the students were not jumping up and down, although it was reported at the time that they were. So it looks like probable static overloading, not dynamic loading. | Terry Porritt (14) | ||
| 1416903 | 2016-03-06 19:11:00 | my view is thats the problem right there. the balcony is not built for 20 people but can fit 20 people on it. Cars are not meant for loads of people at once either....usually 4 comfortable and 5 at most. But people do stupid things. And then everyone blames the product? |
pctek (84) | ||
| 1416904 | 2016-03-06 20:34:00 | its a bit ridiculous having a 20 seater bus that is meant to only carry 8 people and breaks in half when you put 20 in it. no , lets make relevant comparisons, instead of your stupid one. Its would be ridiculous to have a 20 seater bus & cram 100+ people into it, then have them all jump up & down as the bus goes around a corner. My small ford laser has a towbar on it. That doesnt mean I should attempt to tow a 20ft boat, and then complain when the brakes burn out down a long hill. |
1101 (13337) | ||
| 1416905 | 2016-03-06 21:04:00 | However, if they were just bobbing up and down in time to the music (which wouldn't show in the video as jumping) , at or near to the balcony's natural frequency, then that could add a dynamic component to the static load...the straw that broke the camels back. The first reports of the balcony bouncing and people jumping cant be completely discounted, even if they weren't at the time of collapse. A lot depends upon the video and how long the balcony was in view. |
Terry Porritt (14) | ||
| 1416906 | 2016-03-06 21:41:00 | no , lets make relevant comparisons, instead of your stupid one. Its would be ridiculous to have a 20 seater bus & cram 100+ people into it, then have them all jump up & down as the bus goes around a corner. My small ford laser has a towbar on it. That doesnt mean I should attempt to tow a 20ft boat, and then complain when the brakes burn out down a long hill. True. Equally, if someone gets hurt or killed when students try and fit 28 into a Mini Minor is it the manufactures fault? I don’t think so. |
B.M. (505) | ||
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