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)
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)
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. […]