When a sinkhole opened up in Pennsylvania State Route 422 in 2019, Gannett Fleming partnered with PennDOT to accelerate investigation and design and ensure the roadway was fixed and reopened to the public as quickly as possible. The solution was a rather involved micropile supported reinforced concrete slab. The depth of the micropiles extended as deep as 180 feet to tag into competent bedrock. Gannett Fleming’s newsletter, Forces of Change, describes more about the project. One cool thing is that you can watch a time lapse video of virtually the entire construction process. Check it out.
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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."