Despite warnings, repairs to San Francisco’s Millennium Tower caused additional sinking – CBS San Francisco
By Abigail Sterling and Max Darrow
San Francisco (KPIX 5) – Construction to repair the Millennium Tower in San Francisco Stopped in late August Because the repair was actually making the tower sink more. Now it looks like some of that damage could have been avoided.
Construction is partially back on track, with some trial drilling underway this week. The engineers have a plan to dig just two casings with a modified technique that they say will cause less vibration.
“The Millennium Partners wanted to have it all,” said Robert Pike, a geotechnical engineer and one of the early critics of what is now called an “ocean stack upgrade.” He says the $100 million plan to support the sinking tower should have been halted months before it was.
“Certainly by the end of June it was clear that there was an additional settlement as a result of the casings and piles being installed,” Pike said.
KPIX asked him to review engineer records and internal emails obtained by KPIX 5. The team’s graph shows the accelerated sinking began in mid-May but work on the project continued through June and July.
In an email dated July 29, the Engineering Design Review Team (EDRT) hired by the city to oversee the project warned building officials: “The design team suggested to the Homeowners Association on Task 301 that 36-inch casings be installed along the task street and temporarily halted. , “But…” No action has been taken on this proposal and the project continues to move forward.”
On August 4, chief engineer Ron Hamburger finally confirmed that “the project has been voluntarily halted” for the installation of 36-inch casings.
But drilling continued to install smaller, 24-inch piles until August 23, when the Millennium Tower’s general manager announced a temporary halt in all construction for two to four weeks.
“I credit the EDRT with applying the necessary pressure, but they shouldn’t have done it. Any responsible engineer should have called for a halt, as I said by the end of June,” Pike said.
Pyke believes that two months of construction continued to cause further damage.
“Another half to three-quarters of an inch of settlement,” Pike said.
He says continued excavation may have exacerbated the sewage problem in a luxury high-rise building, which was described in an August 26 email as “third-floor kitchens with some blockage.”
“Even a slight change in the slope can disturb plumbing, whether it’s sewage or sewage,” Pike said.
In a statement to KPIX, lead engineer Ron Hamburger admitted that some of the sinking and tilt could have been avoided by halting construction earlier. In a letter to construction officials, he also admitted that the new trial drilling that began this week could cause more sinking. However, he insists that none of this will affect the integrity of the building.
But one thing is for sure: All the problems at 301 Mission Street seem to have an impact on property values. We found ten ten apartments listed for sale, all at reduced prices. Zillow estimates that one luxury apartment listed for $1.75 million was worth about another $1 million just five years ago.
Some units have been on the market for months. Unit 14H, for a bargain of $899,000, has been on sale for nearly a year.
Pyke believes that concern about property values may be one reason the Millennium Tower Society has continued to operate.
“This would suit existing homeowners and the Homeowners Association because once construction is complete and construction is finished, there is no doubt that property values will rise,” Pike said.
The Millennium Tower Association representing homeowners still does not comment. Interestingly enough, we found an online presentation that Hamburger gave in February to students at the University of Minnesota that seemed to confirm that property values are at the heart of all this. In it Hamburger notes that “there is no structural reason to upgrade a building. Homeowners need a major retrofit” to re-evaluate their ‘units’.
No real estate expert was willing to sign up for this story. But someone had access to current data for us which shows 13 listings in the building have either expired or been taken off the market since January.
Ron Hamburger’s full statement for KPIX 5:
“While some of the leveling and tilting that occurred in recent months could have been avoided by halting construction earlier, neither the building’s safety nor its function was affected and the project team has collected valuable information about the reasons for this leveling as construction progresses. This puts us in a better position To mitigate these impacts as we move forward to complete the project. On the day the 36″ pile installation was recommended to be discontinued, the HOA Millennium Tower instructed the contractor to discontinue, in line with my recommendation.”