Sunday, December 27, 2015

Life of a Civil Engineer in the Tongass 2015

Normally I take my work camera when I'm roaming around the forest in an effort to address the latest engineering challenge but every once in a while I'll drag along the SLR... Usually just if I'm going somewhere picturesque and the weather's nice.  
I'm an early riser, but sometimes I have to get up extra early to address a pressing issue.  I can't remember what the issue was on March 17th but I do remember getting on my bike then promptly getting off, going into the house and getting my camera for a little photo session.  I'm pretty sure the issue was still waiting for me when I showed up at the office at dawn.  

This year we were asked to design a dock system for Anan.  The project has been talked about for some years so we grabbed the survey and conceptual designs and headed out to the site with a few key team members.  To be exact, the archaeologists.  The stake above was likely cut and placed as part of a fish trap (think a corral for fish, except the "gate" is actually the falling tide - the fish subsequently get trapped and beached) hundreds of years ago, covered by sand and then uncovered by wave action.  To avoid the historic feature, we wandered around trying to figure out a potential site that does not impact the history of the site.  

...More wandering.  Jane, our Archaeologist from Petersburg looks over the beach area with Mike, an engineer who was responsible for the site permitting.  Carey, in the background, assists Jane with documenting and mapping out the sites.  The wave action covers and uncovers features from year to year.

A dense field of stakes.  This particular field of stakes has been visible for a few years as evidenced by the barnacle growth.  

Here is another type of fish trap.  An arc (now filled with silt) of cobbles was placed along the beach and operated on the tides.  I have photos of a similar fish trap near Kunk Creek that was still catching fish.  We eventually decided to site the potential dock on the other side of this trap where the beach was shorter and the where we could avoid the historic features.  

Another alternate site with our boat floating in the background.  

On a separate trip to Anan took a look at some slope instability and structures that were in need of repair.  Being that Anan is a popular place with the bears, it is advisable to avoid some types of treated wood because the bears like gnawing on it.  It's so bad in places that I've seen some of our bridges with approach rail (guardrail) cantilevered out into space with stalagmites of timber rising from the ground where the rail post once stood.  

I don't know how many landslides I've seen during my 11 years on the Tongass.  But I do know one thing, there are a lot of people who don't realize how frequently land moves.  Sure, their house may have been there for years and it may be there for many, many more years but there is no chance that I would ever consider buying it.  This little slide took out a trail and if it happened on a road I'd have it cleaned up in no time and would have hardly taken notice of it.  But in some places these events just draw a lot more attention.  Even though I see a lot of slides, this one was a little unique.  It was a pure rotational slope failure.  

This spring I worked out of Juneau for a few days and was asked by our dams engineer to provide some details about the condition of this unique structure.  It is a wood crib dam.  Something I had never heard of just a few years ago, but now I've seen a whole bunch of these.  This one has been in place for over 100 years.  In all the examples I've seen I have yet to see a spillway structure.  As unusual as it may seem, it seems like water was meant to flow over the top of the structure.  Not being maintained for the past 80 or so years has meant that the dam has significant internal voids (had been filled with rock) and the crib structure is eroding from water and other material continually falling on the unprotected cross members.  

When I climbed around on this thing I found spikes that were likely used to hold planks in place that protected the crib members and the fill.  

Being a dedicated engineer - and not too shy - I stripped to cross this river to get a closer look at the dam.  The water was painfully cold.  

The plank facing of the dam had broken/eroded away over the years in some areas but it was still visible here.  This dam was constructed to provide a reservoir for a hydroelectric plant.  I'd have to study my Juneau history a little more closely, but I'm pretty sure I saw mining relics in the area and I suspect that the hydroelectric development may have been coupled with mine development.  


A different view than most of the 550,000 visitors enjoy of the Mendenhall Glacier.  The building below is the Mendenhall Visitor Center.  We are in the midst of a design effort that will improve the efficiency of the site and anticipate pursuing a LEED (Leadership in Energy and Environmental Design) certification (likely Gold) for the building as we implement the changes over the coming years.  We are also providing support for a master planning effort as the transportation, bear/human interactions, and outlying facilities are undergoing review and the decision makers look to provide safe, efficient, and enjoyable viewing opportunities as more and more humans flock to the site to see the wildlife and spectacular scenery.  

Tough job.  But I have to pay the bills somehow.  


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