Amazing video of a rockslide as it happened yesterday along U.S. Highway 64 in the Ocoee River gorge in Tennessee. TDOT crews had almost finished removing rockslide debris from an event earlier in the day when a second slide occurred, blocking the road again. That looks like a pretty planar joint set dipping right into the roadway and everything was wet from the recent rains. Click through for the video.
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)
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]