4 ms·

How much would it have cost to dig down to bedrock, and pour a concrete foundation from the bedrock up to surface level? Between the amount of sand to be moved

How much would it have cost to dig down to bedrock, and pour a concrete foundation from the bedrock up to surface level? Between the amount of sand to be moved and the amount of concrete to be poured, it sounds like an enormous fortune; I guess that the relevant questions are whether the market could bear it and whether it would be cheaper than the rapidly-developing lawsuits. It may be that the building didn't make economic sense in the first place, if it couldn't be built both safely and profitably -- which has unpleasant implications for the SF housing crunch...

WalterBright 10y ago
The real problem with digging down to bedrock is destablizing the building. Though there may be enough redundancy in the pilings to do it one at a time.
- vonmoltke 10y ago
  I think the question was why the builders didn't do it in the first place.
  - jonah 10y ago
    You dig down 200 feet to the bedrock, pour a foundation, and then pour pilings up to the surface to put the building on.
clock_tower 10y ago
Update: I hadn't known that the usual practice was to build a foundation down to normal depth for a foundation, then set up (large numbers of) pilings from the foundation down to bedrock. That makes sense.