Seems to me they could just inject cement under the structure, no?......................
The fill underneath the building is unstable—it was built on the ruins of the 1907 earthquake.
What could possibly go wrong?
;-)
The problem is that it wasn’t built on bedrock, and they tried to use friction piling instead. But that didn’t work.
Injecting cement or concrete won’t solve the problem; it will just displace the soft ground underneath it.
It’s built on fill. The piles installed during construction were inadequate (friction piles I believe). The repair included many piles to bedrock and that process was started. Then political infighting began between contractors and engineers. The fix was halted, then resumed under far less ambitious conditions and the tilting continued. The building is doomed IMHO.
Partly it’s the city’s fault. The builders however counted on the city not doing something stupid, and did something stupid themselves — they didn’t drill down to bedrock during the foundation phase of construction.
An engineer known for fixing stuff like this was consulted, he told them they needed to shore it up from the deep center of the foundation, but that was much more expensive, so they did what he warned them not to do, and tried shoring it up from outer edges at street level. The tilt got worse.
Give or take a quake (for which SF is best known), the building will come down, uncontrolled, and on its own schedule, and will damage and perhaps tip one or more neighboring buildings. It needs to be evac’d and dismantled (probably can’t be imploded due to proximity of other highrises) while there is still time.
My guess is, it won’t be.