Monthly Archives: September 2018

One benefit of working with friends is the non-work time we spend together, like sharing meals.  Longtime collaborator and good friend Steve Dickenson joined us in San Francisco for a project meeting last week.  While the meeting achieved the intended outcome, the real highlight of the day was the excellent bahn mi sandwich shop that we found on Eddy Street.  L&G Vietnamese Sandwich is a no-nonsense, locally owned, quick service shop. Lunch for the three of us cost less than $20, which surprised me considering we were in the middle of San Francisco.

The bread had the exact right texture, the jalapeno slice on top added the right amount of bite, and the rest of the ingredients were super fresh. There’s no seating in the shop, but there’s plenty of great public space in the neighborhood.  Here’s their website in case any of you guys need to pre-order before your next meeting in the Civic Center neighborhood:  http://orderlandgvietnamesesandwich.com/

The Atlas Geotechnical blog doesn’t really focus on restaurant reviews, but the unique experiences we collect in the course of our work-related travel are a thoroughly satisfying part of our careers. From Seattle seafood to a great hole-in-the-wall yakitori place on Oahu, from proper Kansas City bar-b-que to amazing camp meals in Athabasca, we share a lot of great meals with good friends as a direct result of our unique engineering practice.  Sharing great bahn mi with a good friend in San Francisco is another great memory from a 30-year engineering practice that just keeps getting more and more interesting.

Seattle imposes a local requirement for verification testing of shoring tiebacks in addition to proof and performance testing. Because the required test load is 2.0 times the design load, and our design safety factor is 1.5, the test is almost certain to fail the anchor on the soil/grout interface.  At least, if our design achieves the target conservatism, the verification test ought to fail the soil/bond interface; otherwise our strength estimate is low and our design is pointlessly conservative.

One charming aspect of such high test loads is that verification anchors need additional strands in order to safely transfer the test load down to the bond zone. (We prefer to test a typical bond length with extra strands rather than use a typical strand count and shorten the bond length.) that means that the test anchors look really robust. The anchor below is only a 180-kip anchor, but it has 9 strands because it’s going to be tested to 360 kips.

Another fun aspect of testing sacrificial anchors is that they need to be installed in between soldier piles so they don’t take up the pocket for a production anchor. That means that we get to use a cool reaction frame for the test. Setting the frame is an extra step, but I think it makes the test setup look super old-school.

Really, though, the point of this post is just to share the photo that Wes sent down from the jobsite. The test results, to be honest, were disappointing.  The setup is really clean and efficient, though. We’ve already installed a similar anchor and then post-grouted it looking for higher capacity. I expect that later today we’ll have a similar photo of a great looking verification test and also proof of the high strength we used in our design.

Is it just us, or does it seem like earthquake activity has been particularly high this summer? Even while I’m writing to talk about a fascinating photograph of slope failures in Hokkaido, but also this morning was another major event near Fiji.

For those of you just interested in the photo, here’s a quick link:

Mudslides in a wide range by magnitude 6.7 earthquake(Atsuma, Hokkaido, Japan）
byu/maruhoi inCatastrophicFailure

Here’s the link to an article about the Hokkaido event and also, I believe, the photo’s source:

http://the-japan-news.com/news/article/0004713745

None of those failure are on the scale of the Oso landslide in Washington, but the cumulative volume is quite considerable. Thankfully the terrain is so steep that the area is sparsely populated.

So far this summer damage has been generally modest despite some of the earthquakes being quite large. Let’s just hope that it continues that way.