Army Corps Looking for 100 Million Cu Yd of Clay
Failures
Mill Creek Dam near Walla Walla, WA Leaking, Receives Corps Worst Rating
The Mill Creek Dam near Walla Walla, Washington has served its purpose admirably for over 67 years but according to a recent report by the US Army Corps of Engineers, the dam received a Dam Safety Action Category (DSAC) rating of 1 out of 5 which means that the risk to public safety is too great when Bennington lake which is formed by the dam is more than 17% full for an extended period of time. More after the break. (Photo by USACOE)
Project Related
Remediation begins on Center Hill Dam, Tenn.
[snip]
"The blasting will be to excavate a platform for construction, about 40 feet wide and will look similar to a road cut through a hill," [Corps Project Manager Linda Adcock] said. "Just the nature of how we grout, and moving equipment back and forth on the current slopes, which are as much as 40 percent and greater, is just really difficult. So for these reasons, for safety, quality, the accuracy and the consistency of the drill holes are much better done from a platform, they proposed this road cut type of a platform."
The drilling is for grouting remediation of the dam foundation. Story from Herald-Citizen, Cookeville, Tennessee.
Project Related
Deleware Forced to Redesign Unfinished Bridge Because of Consolidation Issues
[Update 2/10/08] Updated the name of the bridge. [/Update]
DelDOT is putting the new Indian River Bridge over out to bid. The current bridge is said to be in danger of failing between 2008 and 2012 according to the Army Corps of Engineers, seems to be related to scour. From what I hear, the tidal currents at that inlet being spanned over are tremendous, with water velocities on the order of 35 mph.
In 2005, Mactec, a geotechnical firm, provided a geotechnical report and associated recommendations to DelDOT for how to construct the 45-ft high approach embankments for a 1,400-ft long bridge in light of a 60-ft clay layer (sounds like pre-loading). However, the embankments are not settling as Mactec predicted (not sure if its more or less, probably less meaning slower) and are "shifting laterally" (squeezing?) so the DOT is going with a longer bridge to span the problem soil. More after the break.