The 645-foot tall Millennium Tower in San Francisco settled an incredible 16 inches, and tilted at least 2 inches to the northwest. Recently the City and County Department of Building Inspection (DBI) issued interim guidelines […]
The residential high-rise Millennium Tower in San Francisco has settled a total of 16 inches since opening, 2 inches deferentially. A spokesman for the tower owner blames the settlement on the excavation next door for the Transbay Transit Center, a $2.4 billion dollar project being constructed 60 feet underground.
However, the Transbay Joint Powers Authority (Transbay) hired geotechnical firm Arup in 2010. Their initial report indicated that the tower had already settled 10 inches by the time excavation began for the Transit center. Arup seems to have been tasked with design, installation, and perhaps monitoring of a geotechnical monitoring program, some information on the scope is available in a 2012 presentation given by Arup available on the Transbay website.
[Editor] Click through for the rest of this post. [/Editor]
THE WOODLANDS, Texas, Sept. 18, 2013 (GLOBE NEWSWIRE) — Layne Christensen Company (Nasdaq:LAYN) ("Layne") today announced that its Geoconstruction Division received a contract to provide specialized foundation work in connection with the construction of Transbay Tower in San Francisco.
The contract has an estimated value to Layne of approximately $19 million. Work on the project is expected to commence in October 2013 and last approximately 6 months.
[Editor] Read on for more info about the foundations for this new 61 story high-rise in downtown San Francisco. [/Editor]
This is a great video showing the application of ground freezing to deep excavations in unstable soil and high groundwater table. It’s also a nice overview of the reason the Hetch Hetchy project was undertaken, […]
The 2-year process of excavating the 3,389 foot long fourth bore of CALTRANS’ Caldecott Tunnel is nearly complete. The tunnel is anticipated to be put into service in 2013 to help relieve a major traffic […]
GeoPrac Sponsor Nicholson Construction was recently awarded the contract for geotechnical construcion on the San Francisco Central Subway Project along with join venture partner Condon Johnson. Nicholson’s scope will include diaphragm walls at the tunnel […]
The San Francisco Public Utility Commission has a $4.6B program in place to try and make the water storage and supply system for the Bay Area ‘earthquake proof’ by 2015. It involves 86 separate projects, […]
The USGS has a documentary on landslide video on landslide danger in the San Francisco Bay area entitled “Riding the Storm”. I think the target audience is more general than geologist or engineer, but it is still interesting. The bullet points from the USGS site:
- A catastrophic 1982 rainstorm triggered 18,000 landslides in the Bay Area, claiming 25 lives and causing $66 million in property damage
- The combination of steep slopes, weak rocks, and intense winter storms make Bay Area uplands an ideal setting for landslides
- Landslides include both swift, potentially deadly debris flows and slower, but destructive deepseated slides
- Learn what USGS scientists have discovered about landslide dynamics and which slopes are most susceptible to sliding
- Hear the devastating stories of Bay Area residents affected by landslides and learn to recognize the danger signs
Click through to view the trailer and for links to download the full video. (Image credit: USGS)