Subject: RE: Appropriate Seismic Risk for Earthen Dam
From: "Sprague, Harold O." <SpragueHO(--nospam--at)bv.com>
Date: Tue, 9 May 2000 08:47:44 -0500
"State-of-the-Art for Assessing Earthquake Hazards in the United States",
Report 29, U.S. Army Corps of Engineers Waterways Experiment Station, E. L.
"Earthquake probability in engineering- Prt 2: Earthquake recurrence and
limitations of Gutenberb-Richter b-values for the engineering of critical
structures", E. L. Krinitzsky, Engineering Geology, 36 (1993).
> -----Original Message-----
> From: Laurence B. Oeth [SMTP:viacalx(--nospam--at)europa.com]
> Sent: Sunday, May 07, 2000 12:51 PM
> To: seaint(--nospam--at)seaint.org
> Subject: Appropriate Seismic Risk for Earthen Dam
> Please consider the following: Earthen dam, circa 1920's and 1940's
> construction (phase 1, then heightened in phase 2), currently Zone 3.
> Slope stability on downstream face was analyzed for 10%/50 year event and
> found to be 1.0.
> This dam impounds drinking water for a moderately sized community
> (70,000+), with the treatment plant immediately below. High population
> densities are somewhat removed, however. It seems to me, given the
> potential results of failure that this structure should be evaluated more
> stringently than just any old office building...say 2%/50 year OR set the
> performance level to "Immediate Occupancy" at 10%/50 year.
> Anyone out there have an enlightened opinion regarding input ground
> Regarding the virus: With an opening line of "I love you" it obviously
> wasn't aimed at structural engineers. Now, if it had a subject line of
> "LRFD vs ASD" we'd still be cleaning up the mess....
> Thanks for any ideas - you are welcome to email me directly at
> loeth(--nospam--at)brwncald.com <mailto:loeth(--nospam--at)brwncald.com> if you feel discretion is
> Larry Oeth PE