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New from Snet: Lithologs, a new tool to create lithological/sedimentological logs online..

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Video: Ground Freezing and the Hetch Hetchy Water Supply Tunnel

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, to replace aging San Francisco Bay area water supply infrastructure that would not survive a major earthquake on the Hayward Fault or San Andreas Fault.  I tried to find the name of the ground freezing contractor…I think it was SoilFreeze based on a quick shot of a logo on some equipment.  Can anyone confirm?  The vertical access shaft being constructed in Newark will be where the TBM will be disassembled and removed.

Source: ASCE SmartBrief | Impressum