Golder Associates posted the video below describing some of their work on the York University Subway Tunneling Test Monitoring Project, part of the larger Toronto-York Spadina Subway Extension Project in Toronto, Ontario, Canada. The tunnels came within 6 meters of a “show-piece” building on the York University campus, and the stakeholders were nervous about possible damage to the building. Golder designed an instrumented tunnel test section in advance of the segment under the building, allowing monitoring of the tunneling techniques and potential ground loss so that the team could eventually green-light the dual tunnels under the building. [Editor] Disclaimer: Golder Associates is my day-job employer. They are not affiliated with GeoPrac though. [/Editor]
[Update 2-25-2013] Some of the Golder Marketing folks wanted to tweak the video, so it will be removed for a few days. Once someone tells me the new version is up, I’ll embed it once again. Sorry about that! [/Update]