Really crudely:
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Not every building will have a transfer slab. On most buildings piles are driven into the bedrock and columns are placed vertically above them all the way up to the top of the building, so that in effect the penthouse is sitting on a column that reaches all the way down to bedrock. On a building whose tower has a dramatically different floorplate than the floors below (Maple Leaf Square comes to mind, I'm sure there's others) the necessary column pattern in the tower won't match the necessary column pattern in the podium (or parking garage, or wherever), so you pour a ridiculously thick transfer slab with massive amounts of rebar in it, allowing you to shift the locations of columns. In effect, the tower is no longer sitting on piles that go all the way into the bedrock, but instead is sitting on a massive block of concrete that is in turn sitting on piles that go all the way into the bedrock.

Well put.

the_more_you_know.jpg
 
Thanks for your very complete answer. I was not at all embarassed to ask as I know SFA about building construction.
 
Really crudely:
Attachment 6874

Not every building will have a transfer slab. On most buildings piles are driven into the bedrock and columns are placed vertically above them all the way up to the top of the building, so that in effect the penthouse is sitting on a column that reaches all the way down to bedrock. On a building whose tower has a dramatically different floorplate than the floors below (Maple Leaf Square comes to mind, I'm sure there's others) the necessary column pattern in the tower won't match the necessary column pattern in the podium (or parking garage, or wherever), so you pour a ridiculously thick transfer slab with massive amounts of rebar in it, allowing you to shift the locations of columns. In effect, the tower is no longer sitting on piles that go all the way into the bedrock, but instead is sitting on a massive block of concrete that is in turn sitting on piles that go all the way into the bedrock.


Thank you for the explanation! Now considering what just happened in Japan, which of these types of construction would best survive an earthquake?
 
Colour selection appointments will beging in April 2011. Concrete forming of 4 storey podium should be completed by the Fall of 2011. Forming of residential tower should begin then, with 1st occupancy slated for June 2012. 6 months should be enough to complete, and made ready for occupancy, 1st few floors? That is, assuming there are no unexpected delays.

The building has to be up to somewhere in the 50's before the elevators can be operational. If I recall there are six cabs that serve the first 50'ish floors then another 3 that serve the units above so occupancy can't begin until the elevators are working, so they have to be past the 50's before that can happen. No one will be living here until at least 2013.
 
Toronto is not likely to have an earthquake anywhere near the magnitude of the Japan quake, being on the Canadian shield. It's about as likely as us being wiped out by a giant tsunami on Lake Ontario.
I wouldn't loose too much sleep about it. That being said.... these could be famous last words! :)
 
Now considering what just happened in Japan, which of these types of construction would best survive an earthquake?

first, some background information ...
the Great Hanshin Earthquake, with a moment magnitude of 6.8, struck on January 17 1995. the epicenter was 20 km from Kobe, Japan. the city had a population of 1.5 million and 4600 of its citizens died in the earthquake. across the southern part of Hyogo Prefecture: 200 000 buildings collapsed, over one hundred quays in Kobe were destroyed and significant lengths of Hanshin Expressway fell to the ground.

as a result of the Great Hanshin Earthquake, building codes in Japan (for modern infrastructure) became among the world's most strict and comprehensive. i highly doubt anything built in Toronto even approaches the standards of high-rise structures built in Tokyo in the past 15 years. modern buildings in Japan are designed to bend and shift. obviously, there are limits to these designs.
 
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I was approximately 40 floors up in Tokyo Midtown when the earthquake hit a couple of weeks ago and the building definitely did a lot of bending but it didn't break. Trying to walk down the hall was like being on a ship on rough water.
I'm very thankful for Tokyo's building codes. Lots of ugly but safe buildings.
 
Toronto is not likely to have an earthquake anywhere near the magnitude of the Japan quake, being on the Canadian shield. It's about as likely as us being wiped out by a giant tsunami on Lake Ontario.
I wouldn't loose too much sleep about it. That being said.... these could be famous last words! :)

Be considerate and compassionate in your comments, guys. AURA is going to be my future home.
 
[video=youtube;JhJzdtzl6KY]http://www.youtube.com/watch?v=JhJzdtzl6KY&feature=related[/video]

I don't think our buildings are made to do this exactly, but we aren't resting on a fault line on the Ring of Fire..
Being right smack dab on the Canadian Shield and a continental plate, the only thing we'll get are low-magnitude earthquakes (like the one back in the summer).
 
I was approximately 40 floors up in Tokyo Midtown when the earthquake hit a couple of weeks ago and the building definitely did a lot of bending but it didn't break.

exactly. lessons learned from the Great Hanshin Earthquake of 1995 include having extremely strict building codes to ensure new buildings are very good at handling seismic energy. for a population of 12 million people, there are a surprisingly few high-rise structures in Tokyo; most of which are in Shinjuku-ku and for good reason. for those with travel plans to Tokyo, Japan (i'll be there later this year), i recommend visiting the Tokyo Metropolitan Government Building (Tower One and Two) which rises to just over 240 metres. their observation decks are the best places to see the urban landscape where, on a clear day, you can see Mount Fuji. the construction is interesting is that there are no central core in either tower. the exterior walls are the load bearing members. in fact, the towers are designed to twist and not sway in the event of an earthquake.

anyways, back to Aura ...

as with most everyone here, i'm pretty eager to see this development slowly crawl upward toward the sky. as a downtown Toronto resident, Aura will certainly have an impact (and a good one, i hope).
 
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