From: Chet Soydemir
To: Ron W. Bygness
Subject: GSI News
Dear Editor of Geosynthetics:
I read with great interest the “GSI News” section prepared by Dr. Robert Koerner in the August/September 2011 issue of Geosynthetics (“GSI’s second Inspector Certification Program.”)
It is indeed illuminating that 64% of the “failure mechanisms”Â observed in the failed MSE walls, berms, and slopes is “water related” (i.e.,Â “internal” and “external” water),Â whichÂ comprises nearly two-thirds ofÂ all “failures.” In other words, if I may suggestÂ “failure” is associated with “inadequate drainage.” I first learned this phenomenon from Prof. Arthur Casagrande in 1958.
If I may also suggest that most often the design of MSE walls, berms, and slopes is performed by the contractor’s technical staffÂ who assumes drained conditions in the designÂ toÂ stay competitive.Â I strongly believe that drainage isÂ more so a design issue than a construction issue, and it should be implemented by the project’s geotechnical engineer.
Thus, I think that even thoughÂ the planned “second GSI Inspector Certification Program” is sound and useful, the more critical issue is toÂ facilitate theÂ interaction between the geotechnical engineer and the contractor inÂ every (small or big) MSEÂ project in dealing with the drainage elements.
Chet Soydemir, Ph.D., P.E.
Senior Geotechnical Consultant, Environmental Compliance Services Inc.,Woburn, Mass.
Dr. Soydemir has written a wonderful letter that fits perfectly into our perspective of the issue.
We only wish that GSI could facilitate (make that “force”) the interaction between the geotechnical design engineer and the owner/contractor/project manager. [Unfortunately], that is beyond our means and capabilities.
What we can do (albeit, somewhat less directly) is to have qualified field inspectors who can:
- transmit design oversights to the geotechnical design engineer and
- to report contractors’ inadequate performances to the owner/contractor/project manager.
Our hope at this point, since the program is just beginning, is to have stakeholders in the technology recommend and implement the use of these certified field inspectors of MSE walls, berms, and slopes. We encourage the readers of Geosynthetics magazine to do so and to distribute the information to others as well.
Bob and George Koerner
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