Hillsborough County Florida is using a mix of expanding polyurethane foam and conventional cement grout as a more cost effective means of filling sinkholes. Officials say the mix uses 30 to 40% less grout adding up to a 30% cost savings. The article in the Tampa Tribune did not indicate the contractor or product name that they are using but apparently several agencies in California and other states are using the same material. Story via ASCE SmartBrief.
Failures
Subway Tunnel Collapse in Cologne Germany
Early indications are that a collapse of a subway tunnel station still under construction was to blame for the sinkhole that destroyed Cologne’s Historical Archive, home to documents dating back to 922 A.D. More info after the break. (Photo by DPA via Spiegel Online)
Failures
City of Vancouver sues over failed shoring
The City of Vancouver is suing a developer, excavation contractor and their consulting engineer for the costs of repairs, overtime for city employees and lost revenue from parking meters etc stemming from an apparent failure of a shoring system that formed a 30-meter sinkhole. No mention of the developer’s name or the engineer, but the contractor was Matcon Excavation and Shoring. The site will be the future home of high-rise condominiums…if the City lifts it’s stop work order.
The failure of the shoring caused a break inf a 20-cm water main ultimately flooding the site. It also necessitated the closure of the adjacent street. Of course this invites the whole chicken or the egg scenario. The defendants will probably argue that the water line failed first causing the failure of the shoring, but of course the City Engineer, Tom Timm was not shy about fingering the shoring as being deficient.
"It’s some kind of a failure of the shoring system . . . either a design issue or the way it was put in place."
Rockman's Ramblings
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