The area is approximately 300-m from the Rhine River, and groundwater is very shallow. As noted in another NCE article, the contractor constructed 15 dewatering wells when only 4 were approved. Additionally, the pumping rate being used was 750 m^3/hr, or nearly double the 450 m^3/hr it was pumping in December of 2008. Clearly the groundwater is one component of the failure, but it does not appear that there is sufficient evidence to say exactly what role of the groundwater was or if the shoring walls did in fact fail and lead to the collapse of the Cologne historical archives and the deaths of two people.
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 […]
ENR reports that a Tunnel Boring Machine or TBM is stuck for the second time in two weeks on Pittsburgh’s light rail expansion project dubbed the North Shore Connector Project. As we described in a previous post, the project will consist primarily of a tunnel underneath the Allegheny River. The drilling began the week of March 3 and has been progressing at a rate of 30-ft/day or 5-ft/day faster than the original goals. Read on for a location map of the project, or download the Google Earth KMZ file showing the project area. (File photo of TBM)