Author answers question regarding dams “post-construction”

Editor’s Note: A question was posed regarding the article “Geotextiles in dams: Forging federal guidelines,” by Douglas Crum, (August/September 2008, Geosynthetics).

Question

I am curious to know more about the post-construction issues here. What kinds of guidelines exist or should exist?

David M.

Reply (from the author)

David,

One thing about water resource dams is that once constructed, they become landmark structures. Very few are removed, so “post-construction” extends to very long time periods.

Long-term operations and maintenance (O&M) can be an uncomfortable issue for designers and constructors because we have little control about how future generations choose to maintain infrastructure. How we are currently maintaining our infrastructure has been a political topic in recent U. S. federal budget debates. It is interesting to note that the ASCE manual of professional practice, “Quality in the Constructed Project” includes a chapter on operation and maintenance that discusses the design phase, construction phase and startup phase, but never addresses the long-term.

The designer’s capabilities to impact long-term, post-construction actions are usually limited to preparing an O&M manual and setting up an instrumentation program.

In some rare circumstances, geosynthetics have been exhumed and tested from existing structures. Giroud points out a specific example of such testing for a geotextile filter at the Valcros Dam. (Giroud, J. P. , 1992. “Geosynthetics in dams: Two decades of experience,” Geotechnical Fabrics Report (GFR), Vol. 10, No. 5, pp. 6-9; and Vol. 10, No. 6, pp. 22-28).

Ad hoc testing of constructed facilities is usually research-and-development oriented (such as the Valcros Dam) or for failure investigation (which is frequently difficult to obtain because of associated litigation). Because a designer has little control over budget and priorities in the distant future, it is very difficult to preplan such testing in an O&M program.

Respectfully,

Douglas Crum, P.E.
Dam Safety Program Manager
Kansas City District Corps of Engineers

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