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> The Millennium Tower’s foundation consists of a 10-foot or 3-meter-thick concrete slab supported by 950 concrete friction piles driven into the subsurface to
by trhway 5y ago
> The Millennium Tower’s foundation consists of a 10-foot or 3-meter-thick concrete slab supported by 950 concrete friction piles driven into the subsurface to a depth of about 80 feet or 24 meters.
When I see modern townhouses slab foundation instead of proper basement (which Archimed law favors as soil is just a very slow liquid in which building is floating like a ship until of course it's piles are driven into bedrock) I cringe at that cost cutting though it is ok for a 3 story building. I never imagined that it would be done to a skyscraper - no basement and no bedrock reaching piles. The story of Millennium tower reminds those buildings in Siberia on permafrost where builders cheated and did shallower than needed foundation - you can notice those buildings from a distance by twisted pagoda style roofs, etc.
- djrogers 5y agoDid you by chance read TFA? There are several references to a basement.
- trhway 5y agoi couldn't find any description of the main tower basement - it all sounds like the main tower slab mat is basically near the ground level. The garage is said to be under the small tower. There are other SF high-rises using slab, yet their piles reach the bedrock. Also Millenium Tower is reinforced concrete instead of typical for such high-rises steel - it was more "economical" - and due to the leaning/sinking stress the concrete there is cracking.
- andromeduck 5y agoThe lack of basement and associated parking makes the architecture incredibly alienating too. Almost everywhere you go, it's all parkades, garage doors, staircases and gates - absolutely insane.
- danans 5y ago> When I see modern townhouses slab foundation instead of proper basement A mat or raft slab foundation - such as the kind used in the Millennium Tower - can be just fine for a small structure such as townhome. A mat/raft foundation is different than a regular slab on grade foundation in that it is thicker and has steel reinforcement running throughout, not just in the perimeter footers. [1] Its strength is due to the way the steel reinforcement distributes loads across the subsurface. My 1600 square foot house is built with such a foundation and I got a close-up look at it during a recent major structural renovation and it is incredibly robust, even over-engineered. Just because it was a bad choice for a skyscraper doesn't make it a bad choice for far lighter structures. 1. https://www.finehomebuilding.com/2019/12/30/mat-slabs-an-inventive-foundation-for-difficult-sites https://www.finehomebuilding.com/2019/12/30/mat-slabs-an-inv...