Leaning towers are not unheard of when it comes to older architecture. “Because the stabilization is still under construction, it has not yet worked to help the building.” “The retrofit is not going to ‘stop the sinking’ until the piles are driven into bedrock and attached to the foundation,” he added. “This will reduce the excessive pressure on the Old Bay Clay materials that caused the original settlement, stop the settlement and allow the building to begin recovering some of the tilt that has occurred. “Once these piles are installed… using hydraulic jacks, some of the building’s weight will be transferred to these new piles,” Hamburger explained. Gabrielle Lurie/The San Francisco Chronicle/Getty Images Experts have blamed nearby construction projects and a process known as “dewatering” for weakening the soil beneath the tower, according to earlier CNN reporting.Ĭonstruction to stabilize the two buildings includes new piles, anchored to bedrock deep below the ground, that will eventually bear the weight. Though engineers are now working to stabilize the skyscraper, a city hearing last week revealed that the tilting will continue for several more months. It has settled around 18 inches deep into the ground. By the end of last year, the tower had leaned a total of 24 inches to the west and 7.9 inches to the north. The tenants were first notified of the issue in 2016. The tallest residential structure in the city, the tower’s uneven settling has caused cracks in the surrounding sidewalk and the basement walls of its smaller, 12-story sister building next door. Opened in 2009, the estimated $350-million project comprises two buildings, the larger of which is home to 419 luxury apartments, including a lavish $13-million, 5,500-square-foot penthouse. If all goes as planned now, the tower foundation is expected to be extended and supported to bedrock on two sides by this spring.San Francisco’s swanky Millennium Tower has been slowly sinking for years – and, as a result, the 58-story skyscraper tilted at a rate of up to 3 inches to the north and west last year, according to the engineer tasked with fixing it. Residents NBC Bay Area talked to said they are still coming to grips with the reality that the tower will likely lean forever. “There's a lot of factors that they have not accounted for,” Williams said. He also worries the tower ended up tilting more than the model predicted last year. “There's a lot of uncertainty,” said David Williams, a deep foundation expert who worries that computer analysis doesn’t specifically simulate the factors that triggered the construction related sinking. But some critics fear that the model’s predictions could be overly optimistic. Investigative Reporter Jaxon Van Derbeken, who has been at the forefront of the investigation for years, has some insight.Ĭity-appointed experts are satisfied with the model’s conclusions, Hamburger said in the statement. San Francisco’s Millennium Tower has been sinking and leaning for years and the final phase of the fix is now underway. Recovery of some of the tilt that has already occurred is a secondary benefit, not a primary objective.” Lead fix engineer Ronald Hamburger said in a statement that the primary objectives “have always been to arrest building settlement at the northwest corner … and stop tilting by transferring a portion of the building’s weight to bedrock. The model projects that once it is secured, the tower will permanently tilt about two feet at the northwest corner. While the fix was billed as providing some relief, it turns out that the fix engineers’ latest computer model shows the construction project will only offset about 4.5 inches of lean, less than half the roughly ten inches of tilt triggered so far during construction. “If I was a resident, I’d still be worried that I can't put something on the table without it rolling off,” Poulos said. Both times, the marble quickly ran out of steam and came back toward that northwest corner. Recently, a resident videotaped an experiment to show what the tilt looks like on the inside – twice rolling a marble uphill, toward the center of a unit near the corner of the building leaning the most. Sign up for NBC Bay Area’s Housing Deconstructed newsletter. Get a weekly recap of the latest San Francisco Bay Area housing news.
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