Video Source: ENR.com.
Project Related
Debate in Illinois over proposed USACE use of fly ash in Mississippi River levee stabilization
The Corps is proposing to use the fly ash as part of a lime slurry mixture for some kind of grouting to stabilize the levees according to the article. Environmentalists are concerned about the potential […]
Standards and Codes
ASTM Updates April 2010
Standards governing the testing of tensile strength of geogrid and geotextile tensile strength are among the standards updated over the past month by the ASTM. This includes a new standard for "Determining Small-Strain Tensile Properties of Geogrids and Geotextiles by In-Air Cyclic Tension Tests". A number of standards relating to concrete including capping of concrete cyllinders for testing have also been updated. Click through for the list.
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)