Hayward Baker will be the geotechnical contractor for the compaction grouting. The article draws a HORRIBLE comparison between compaction grouting and the ‘top kill’ that BP tried to stop the oil leak in the gulf. Honestly, sometimes reading what the media writes about engineering is a little scary. I’m sure Hayward Baker is thrilled to have their name mixed in there with the most hated company on the planet right now! [Source: Nashville Business Journal via AGC SmartBrief]
Failures
Johannasburg Sinkhole Opens after Tunnel Collapse
A 12m long sinkhole opened up on Oxford Road in northern Johannesburg South Africa after a partial tunnel collapse in the Gautrain rail tunnel being constructed underneath the road. Eyewitness accounts say there was a broken water pipe flooding the sinkhole, but no word on which occurred first. The road is expected to be closed for 2 weeks. Gautrain representatives said the tunneling would resume after geotechnical/geological investigations into the collapse are completed, which could take "several weeks". (Photo credit: Werner Beukes, Sapa via News24.com)
Via The Star (Zambia) and News24.com (Johannesburg?)
Articles
Ever get that sinkhole feeling?
It takes planning and good leadership to decide on an effective solution to problems associated with a building asset. Recently, a large wholesale warehouse facility in Cincinnati began to experience large sinkholes across a significant portion of their customer parking lot. Unable to determine the problem at that time, store management was forced to close a portion of the parking lot, inconveniencing their customers. This particular parking lot is unusual in that a drainage system is located directly under the parking lot, consisting of a network of pipes spanning 250 feet in length and 12” in diameter. Joint separations in the underground drainage piping had caused enough soil erosion to create sinkholes in the asphalt. Engineers were concerned that other unknown sinkholes could cave in anytime, resulting in further costly damage, and potentially posing safety hazards to customers.
[Editor] Click through for the rest of the article. [/Editor]
Journal Article Reviews
Mitigation of Karst and Sinkholes for New Hospital Structure
The site for the new Harrison County Hospital, approximately 25-miles west of Louisville, Kentucky had 15 sinkholes formed by limestone dissolution, a geomorphologic process referred to as Karst topography. There were a number of geotechnical engineering and geological engineering challenges associated with the characterization, excavation, backfilling, foundation engineering and other mitigation measures as described by Peggy Hagerty Duffy, P.E. in her article entitled “Karst and Complications” in the August 2008 issue of Civil Engineering Magazine (Duffy, 2008b).
Mitigation measures for the sinkholes included use of graded filters with geotextiles, careful inspection of rock socket foundations along with pilot holes and careful geotechnical inspection throughout the construction process. One particularly interesting aspect of the project is that several of the sinkholes were used as drainage facilities to receive surface water runoff. Read on for a summary of this interesting article. (Photo of sinkhole in Karst Topography being used as a drainage feature, from Duffy (2008b), Civil Engineering Magazine)