121–130 of 187 posts
Reminds me a bit of the CitiCorp Center fiasco. http://failures.wikispaces.com/Citicorp+Center Not only did the architect miscalculate the worst-case wind load on the building but the builder substituted cheaper bolted steel connections for the originally-specified fully welded connections. The problem was remediated by heavily reinforcing the connections of the diagonal steel braces in the frame of the building, but…
> Three Meteorological experts were retained to provide updates three times throughout a day. An emergency evacuation plan was developed in conjunction with local law enforcement, search and rescue, firefighters, major city authority figures, and shelters. 2000 emergency red cross workers were kept on stand-by in the event of a failure.
My house is on a steep hill, and Seattle has a reputation for hills sliding away under heavy rain. Before building it, I hired 3 separate geologists to evaluate the site. After digging holes, they said the site was sitting on "glacial till", which is clay that was compacted by about a mile of ice, and said there was nothing to worry about. Paying them was worth it for the peace of mind. (Turns out the till was so har…
I really hope the SF rules for building giant buildings are similar to recent Japan ones. What I've heard is that after the Kobe earthquake, Japanese earthquake rules have been made so good that anything built after '95 has never fallen over, even in 2011-sized earthquakes (at least until the tsunami came).
However, CA's buildings are mostly older.
...2 inches for such a tall building is such tiny angle If it sinks does this mean the first floor is slightly below the street level ..it probably means that the areas around the door and where the concete meets the street are cracked
Wouldn't the width be a more appropriate measure than height?
tan θ = opposite / adjacent
= (horizontal displacement of top) / heightEarlier quoted context omitted.
It seems that you need to read more carefully and perhaps with more generosity. > A few examples: - Foundations of tall building must go to bedrock - not true. I see few if any comments here asserting, let alone asserting without qualification, that buildings must be built to bedrock. Further, heeding your own advice that expertise should be bidden, note that the apparently expert sources in the article said themselv…
you should instead be grateful for a curt correction to the unending stream of faux-expertise and hand-waving that HN has become I only ever bother with the comments section anymore if only to watch the cringe-inducing attempts at "insight" by the same dozen or so users...
My house is on a steep hill, and Seattle has a reputation for hills sliding away under heavy rain. Before building it, I hired 3 separate geologists to evaluate the site. After digging holes, they said the site was sitting on "glacial till", which is clay that was compacted by about a mile of ice, and said there was nothing to worry about. Paying them was worth it for the peace of mind. (Turns out the till was so har…
Building a large edifice on sand? Put that starkly, I could swear that I heard a story about it once. No idea where, though. ;)
The article doesn't talk about the how this practically affects the entrances to the building. Do the doors have to be adjusted for such a drastic sinkage, or are buildings somehow designed so this isn't noticeable to the public?
"To cut costs, Millennium did not drill piles to bedrock." What are the implications for earthquake safety?
Because Millennium is on reclaimed land, they cannot determine whether or not they have drilled into bedrock. They drill into what's called the 'point of refusal'; a point where they can no longer drill deeper. Whether this is bedrock or even stable soil is somewhat vague.