Geologic Hazards

Allegations: Oregon Not Forthcoming With Landslide Hazard Information

Folks in Oregon are angry about a recent landslide and debris flow that closed Highway 30 and destroyed property in the town of Woodson. (Here is a powerpoint presentation by Bill Burns of the Oregon Department of Geology and Mineral Industries showing how the event happened). Some rather stinging allegations are being made that politicians withdrew a landslide hazard map from general use in 2002 for political reasons. That map or another one had characterized the area effected by the December 2007 debris flow as a "very high" or "extreme" risk of landslides. A very interesting article. 

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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.

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Standards and Codes

US House Passes National Tunnel Inspection Program

The US House of Representatives passed legislation approving a national tunnel inspection program. This of course came about as a result of a fatal accident from 2006 in a tunnel on Boston’s Big Dig project where a concrete ceiling tile fell on a car killing one person. More after the break. 

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Rockman's Ramblings

Problems with Registration and Outside News and Blogs

I just found out that there was a problem with the site that prevented new members from registering on GeoPrac. My appologies to anyone who got a permission error after filling out the registration form. I humbly invite you to try again at your convenience.

Additionally, the Outside News and Blogs page that I was patting myself on the back for has apparently not been visible to the public either. Great big oops on my end. It should be up and running now.

Thank you to Elizabeth at the ASCE Geo-Institute who took the time to let me know about both problems. Do me a favor and check out the new G-I News Feed blog that she maintains.

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Journal Article Reviews

Challenging the Natural Flow Models

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)

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Available Resources

Geo-Institute Website Changes

The Geo-Institute of the ASCE has made some changes to their online services. For starters, they have now posted online versions of the Geo-Strata magazine. The only catch is you have to be a member to read them. Additionally, they now have a blog with an associated RSS news feed. If you don’t use RSS feeds, you can always head over to our Outside News and Blogs page where we have already incorporated this new blog’s feed into our aggregated news.

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Geologic Hazards

More Movement on La Jolla Landslide

For those of you following the landslide in residential La Jolla California known as the Soledad Mountain Road landslide, it made the news again a couple days ago when a section of the slide re-activated and slid 10-ft down the hill. Doesn’t sound like too big of a deal to me, no additional houses damaged. I’m curious how it related to the shear pins they installed a couple of months ago.

Additionally, the San Diego City Attorney has released a report detailing the sequence of events leading up to the landslide. One interesting note is that the Mayor of San Diego is in hot water with the City Attorney’s office for hiring outside legal council to handle the legal aspects of the landslide. According to the City Attorney’s office, he wasn’t allowed to do that, but so far the City Attorney hasn’t stepped in to force the outside attorney(s) to drop the case saying it would open the City up to even more liability.

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Rockman's Ramblings

Personal Reflections on I-35 Bridge Collapse in Minneapolis

On January 15, the National Transportation Safety Board released a safety recommendation letter report to the FHWA related to the I-35W bridge collapse in Minneapolis Minnesota that claimed the lives of 13 people and injured 145. The safety recommendations are based on the findings of an interim report from the FHWA Turner-Fairbank Highway Research Center  that some gusset plates, components of the steel trusses, were undersized (not thick enough). This deficiency was confirmed to be a flaw in the design and not construction-related based on review of the original drawings from the 1960s and inspection of the wreckage. Whether this was a calculation error or a drafting error will perhaps never be known as only portions of the original design calculations were located. But the point is that it was never caught by any reviewers.

When this event first happened back on August 1, I remember being very shaken up by it. After my initial sadness for the victims of the accident, my first thought as a geotechnical engineer was: “were the foundations at fault.” As more information came out, it quickly became evident that the failure did not have anything to do with the foundations but that it was related to the superstructure of the bridge. But this still was something that profoundly affected me. (Continues…)

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Journal Article Reviews

Second Issue of International Journal of Geoengineering Case Histories

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.

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