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.
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)
Geologic Hazards
Hutchinson, Kansas Sinkhole – Site of Former Salt Mine
The new owner of land that used to be owned and mined by the Carey Salt Company is in talks to buy out 32 homes in the area because of subsidence and sinkholes. They have […]
Miscellaneous
London Underground trains hit “bulge” in tunnel lining under River Thames
Grouting work done earlier in the week was a possible cause of a bulge in the lining of a train tunnel under the River Thames. Two trains hit the bulge before the line was closed, […]