Stabilization work on the Millenium Tower in San Francisco was halted in late July after the stabilization work appeared to be further destabilizing the structure.
Last month, the construction company announced that an improved stabilization technique had been successfully tested: Millennium Tower Fix Test Declared ‘Successful'
Fix designer Ron Hamburger told Millennium residents in a notice Thursday that the test was intended to “to demonstrate the Contractor’s ability to use improved procedures to install these casings without causing significant additional building settlement and tilting.”
“I am pleased to report that the test was successful,” Hamburger said. “Total building movement during the test was approximately one hundredth of an inch. This demonstrates that it is possible to install the remaining casings.”
He said a second test will follow, which involves installing a two-foot wide pile through an existing casing down to bedrock. “If this second test is successful, we look forward to a resumption of work and completion of the project.”
The city, however, is not so sure:
City officials, meanwhile, released weekly monitoring data showing that the building continues to settle despite a stop on work since Aug. 22, including an unexplained dip in early October indicating about the same settlement rate as measured before pile installation was halted in August.
Meanwhile, if you, like me, are the sort of person who can't tell the difference between Colma Sand and Old Bay Clay, here's a great overall backgrounder from Grady Hillhouse's Practical Engineering blog with a short video to catch you up on all that's been going on: What Really Happened at the Millennium Tower?
I'm certain this will not be the last status update I write about this project.