The last time we checked in on the sinking, tilting Millennium Tower in San Francisco, engineers believed they had developed a stop to the buildings settling, but that came with a hefty estimated price tag between $200 million and $500 million. The fix called for installing around 300 micro piles, made of concrete and steel, driven to bedrock. A new plan has reduced that overall cost to remedy and will have much less impact on residents.
According to the San Francisco Chronicle, the tower’s homeowners have submitted a permit application for the fix they believe will correct the build’s deficiencies. The $100 million project calls for only 52 piles to be driven 250 feet below to bedrock. Each pile will be constructed of a steel shaft filled with reinforced concrete, measuring 24 inches in diameter and weighing around 140,000 pounds.
22 of those piles will be placed along Mission Street on the north side and the other 30 will be placed on Freemont Street on the west. The soils along those two streets have the most stress placed on them, so engineers believe the piles will relive that stress and allow the building to naturally straighten out over time.
Each pile will take approximately three or four days to drill and will be connected to the existing foundation, which contains 950 reinforced concrete piles driven to around 90 feet deep. The entire project is expected to take 18 months to complete.
The project state date will obviously be contingent on the plans approval process, so that timeline is unknown at this point. Many parties are certainly hoping this will satisfy all complaints in the case, as the Chronicle reported that there are a total of 9 lawsuits currently filed with over 146 lawyers involved.
Full Story: There’s a new plan to stop Millennium Tower sinking — and settle lawsuits | San Francisco Chronicle
Full Story: Millennium Tower homeowners propose $100 million solution to sinking problem| San Francisco Chronicle