This is a commentary written by Jaye Richardson, a materials operation manager with AMEC Earth and Environmental, Inc. It appeared in CE News in August of 2010, but I just came accross it in CENews.com’s […]
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)
[Update 2008-11-03] The Link to the Journal’s homepage requires you to purchase the article. Too bad. Try the CDOT report instead I guess. [/Update]
First off, sorry for the cheesy Halloween tie-in. The other day I read an interesting paper in the Journal of the Transportation Research Record, No. 2045, of the Transportation Research Board (TRB). The paper was titled: “Evaluation and Recommendations for Flowfill, and Mechanically Stabilized Earth Bridge Approaches.” I’ll post the full citation below. (Photo from FHWA NHI Soils and Foundation Course Slides, NHI Course No. 132012)
The authors describe the standard of practice for Colorado DOT (CDOT) projects for the last 16 years with regard to the construction of bridge approaches in an attempt to eliminate the problem with the “bump at the end of the bridge”. They discuss some of the common reasons for problems with approaches, and some possible solutions. Click through for more.
According to the New York Times (by way of Geology.com), researchers from Franklin and Marshall College are saying that early work by geologists and hydrogeologists to formulate water-flow models may have been based on remnants of old dams created by settlers in the 1600s. The implication of these findings is that it changes the way ecologists and conservationists look at streams and what it means to return one effected by urbanization to a "natural state." (Photo by silverxraven)
I’m very pleased to see that the International Journal of Geoengineering Case Histories has finally published their second issue. I was beginning to wonder if they would ever publish again. I was looking for a date of when that first issue was published but I couldn’t find one. But I suspect it’s been at least a year. I was sort of interested in creating a similar type of site when I was first thinking about GeoPrac, but it never worked out. But i digress. Click through for a list of the case histories and some additional goodies.
In the May 2007 edition of Foundation Drilling Magazine, a publication of the Association of Drilled Shaft Contractors (ADSC), Silas Nichols, PE of the Federal Highway Administraton provided a summary of the FHWA’s role in providing guidance on drilled shaft design and construction over the years through research funding, publications and involvement in AASHTO and other agencies. Also in the article is an overview of upcoming updates to AASHTO codes, and FHWA publications. Read on for more details.