Category Archives: Musings

I just started work on a piledriving project where the GT of Record provided final tip elevations, based on 16 indicator piles, for the Contractor’s use in casting the design lengths. With the diagram he included a disclaimer that the site is variable, and that many of the piles might be different lengths in order to satisfy the acceptance criteria. The GT, accompanying the final design information, recommends that the Contractor hire another geotechnical engineer to monitor each production pile and make appropriate length adjustments, and also a structural engineer to design splices.  Without intending, I’m sure, the Owner’s engineer has converted the piledriving part of our project from conventional design-bid-build to a contract that relies on the Observational Method.

The Observational Method is extraordinarily effective on challenging sites, but also can be costly to implement. We use it explicitly on dams and tunnels. Ralph Peck’s 1969 Rankine lecture is, in my opinion, the best summary of the method’s origins, the rigor with which it is to be applied, and it’s significant advantages on projects with terribly difficult geotechnical conditions. Like all Rankine lectures, the paper is worth a read.  You can get your own copy here:

https://www.britishgeotech.org/prizes/rankine-lecture

I link to the full catalogue; scroll down to 1969.  Consider browsing a bit while you’re on the site. And yes, the photo that accompanies this post is my preferred headshot of Karl Terzaghi, not the author. Read Prof. Peck’s paper to understand why.

In my practice I find it helpful to recognize when the design team’s RFI responses induct elements of the Observational method into our project. When they do, it’s time to  evaluate whether or not the character of project has changed fundamentally from the project described in the bid documents. A conventionally procured project offers certainty in exchange for hard bid pricing. Other tendering formats are appropriate for projects where final design will be developed as conditions emerge, as is the case with the Observational Method.

It’s necessary to understand the Method in order to recognize unintentional implementations. Here’s a clip from Prof. Peck’s lecture, for those of you with just passing curiosity.

REVIEW OF METHOD

In brief, the complete application of the method embodies the following ingredients.

  • Exploration sufficient to establish at least the general nature, pattern and properties of the deposits, but not necessarily in detail.
  • Assessment of the most probable conditions and the most unfavourable conceivable deviations from these conditions. In this assessment geology often plays a major role.
  • Establishment of the design based on a working hypothesis of behaviour anticipated under the most probable conditions.
  • Selection of quantities to be observed as construction proceeds and calculation of their anticipated values on the basis of the working hypothesis.
  • Calculation of values of the same quantities under the most unfavourable conditions compatible with the available data concerning the subsurface conditions.
  • Selection in advance of a course of action or modification of design for every foreseeable significant deviation of the observational findings from those predicted on the basis of the working hypothesis.
  • Measurement of quantities to be observed and evaluation of actual conditions.
  • Modification of design to suit actual conditions.

The degree to which all these steps can be followed depends on the nature and complexity of the work.

I am particularly fond of that last statement. “It depends.” In the 50 years since those words were penned by one of the giants in our field, consulting geotechnical engineers have yet to address the fact that, really, the right course of action depends on the nature an complexity of the construction. There is always a way forward, of course, eVen in the most difficult conditions. The level of effort, though, depends on the nature and complexity of the work.

 

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.

Dinkey Creek BridgeIt’s not often that anyone sees the best geotechnical designs.  Dams, maybe, but even with those the classics are all concrete arches. I guess none of us here at Atlas, or any or our geotechnical brethren, chose this career path for the glory.  Those people were all drawn to architecture. Except for a select few who found bridge engineering. That’s one engineering discipline where function and aesthetics blend seamlessly, and where an excellent design is obvious to all onlookers and not just the engineers among us.

And while Portland has recently finished a marvelous cable-stayed crossing of the Willamette (http://trimet.org/tilikum/), I reserve my greatest appreciation for projects that were built without access to the unlimited might of modern construction equipment. A timber bridge built by sincere but untrained CCC crews is somehow in a different category for me, and generates a special kind of appreciation.

Doug Export - 20We came across this classic beauty several years ago while bouldering as a family through Dinkey Creek.  The simplicity of the design was striking, and we paused for an impromptu discussion of load paths, Newton’s second law about actions and reactions, and how to use the method of sections for analyzing trusses.

The budding young scientist in orange standing beside me (and asking insightful questions) started college this past week.  His intrinsic appreciation of beauty in the functional world draws him to studying physics, a significant step up from his dad’s mundane plodding in the mud.  He has a burning interest in answering the most fundamental questions, not simple ones like “how can we cross this creek using hand tools and the forest around us.” I hope that he, and all of us, can find elegant, enduring solutions to the important questions that we consider.

We’ve recently found ourselves working on several projects afflicted by badly flawed numerical modeling.  And not just little errors with inconsequential effect.  These mistakes demonstrate a fundamental misunderstanding about how numerical models work and how to deploy them in Engineering. All of you surely have your own examples of numerical modeling gone awry; here are the two most recent from our practice:

  1. Search constraints in a slope stability model were deliberately set farther upslope than the slope geometry could possibly support, so the Engineer was unwittingly searching for failure surfaces other than the critical surface.  I told the Engineer that the computed safety factor was only valid if the lower (less-stable, light blue) part of the slope could reach up across that little narrow neck at the scarp and grab the upper part (yellow-ish), dragging it down the hill like the caboose on an impossible failure-train.  Yes, we’re interested in the stability of that area back from the crest, but no, forcing the model to violate the basic premise of Method-of-Slices stability analyses does not provide useful insight.Block_Yield Acceleration_Page_1 (2)
  2. Hydrotesting a new canola oil tank caused it to tilt 275 mm across the 36 m diameter. An Engineer was engaged to assess the structural integrity of the tank and, unfortunately, interpreted that assignment as license to run wild with a bunch of structural finite element software. One of the runs showed tank shell stresses 3.5 times higher than the steel strength, which would have caused catastrophic failure before the end of the hydrotest. When I observed that the tank is still standing and the computed result contradicts observed fact the Engineer doubled down on his computations, effectively stating that reality exists in the computer, not the tank.Tank 42

 

It seems to me that modeling failures like these are increasingly frequent as mesh generators and improved interfaces make the software more accessible. The improved speed and efficiency that facilitates competent modeling are just as helpful to the ignorant modelers, allowing them access to new tools that they do not understand and yielding answers that do not represent actual conditions.

I expect that, over time, a few designs based on flawed models will find their way into our built infrastructure. I hope that the resulting losses are only financial, and that before too long we find a way to re-emphasize the proper relationship of modeling in support of engineering, rather than modeling as a time-saving substitute for engineering.

This week between holidays is, without question, my favorite work week each year. This is the week where I clear the decks in preparation for an unencumbered start.  I sort out whatever fussy administrative problem was allowed to linger unresolved in favor of shopping and year-end accountancy. (This year it’s an off-site backup problem; last year was an office furniture need). My white board here at Atlas World Headquarters is full of good uses for this period of predictable calm, and I’ve already started knocking some of them off the list.

For those of you who make resolutions, this is the week that you compose and commit yourselves to making that long-overdue improvement in your practice. Those of us who prefer to skip the resolution stage and simply do the thing, this is the week to make a start and see if the new habit will stick.

We should all recognize how much more productive we are when free of distracting email and conference calls.  Creating such periods of uninterrupted productivity is going to be an important improvement to my practice in 2015, and I would recommend that it be part of yours too. (I use Freedom to turn off teh Interwebs. https://macfreedom.com/  There are many similar programs, and you should use this week to find the one that works best for you.)

Whatever you intend for your practice in 2015, whether you’re still building core competency, diversifying and growing, or starting to contemplate ramping down, I wish you the very best of luck for this preparatory week and great success in the coming year.

TJ Earthquake Damage

Typical Damage at Trader Joes

Friday night’s earthquake in La Habra was interesting for a couple of reasons.

It was small, by California standards, at only Magnitude 5.1.  In fact, I have my automatic notification program set to M6.0 or larger because there are so many small earthquakes like this and generally they don’t cause any damage. I found out about this one through Facebook. So I guess yes, there’s at least one good use for Facebook.

Secondly, the shaking was surprisingly strong for an earthquake of this size.  The rupture was shallow, only 1.7 km deep, and the lack of attenuation up to the surface resulted in  peak ground accelerations as high as 0.25g.  I pasted the USGS shake map below with a handy key to the Mercalli Intensity Scale system of classifying earthquakes.

No serious structural damage occurred, though La Habra Utilities is reporting broken water and gas pipes. The lack of damage and injury speaks more to LA’s excellent building codes and earthquake preparedness than it does to the modest earthquake size. In other parts of the world, places that lack the resources, knowledge, and political will of metropolitan Los Angeles, these types of earthquakes cause fatalities. Intensity VII shaking in California knocks over a stack of wine bottles in Trader Joes. The same level of shaking in rural Afghanistan dislodges roofing stones from their timber supports and buries whole populations in their huts.

Small, generally consequence-free events like these are an opportunity for all of us to reconsider our knee-jerk reactions to troublesome regulations and building codes, a chance for us to give genuine thanks to the smart engineers who led the transition from unreinforced masonry buildings like San Francisco had in 1906 to the well built structures that now protect us from preventable misfortune. Here’s my list of earthquake heroes:

Harry Seed – Pioneer geotechncial engineer and shining light of inspiration

John Lysmer – Smartest good-humored numerical modeler

Vitelmo Bertero – Structural engineer, deep thinker, curmudgeon

CB Crouse – Towering intellect, practical seismologist, mentor

Steve Dickenson – Good friend, collaborator, and insightful earthquake engineer

Yumei Wang – Classmate and dedicated earthquake safety advocate

Jason Brown – Cheerful building code enforcer

Because of their work and the work of countless others, your home and office, your kid’s schools, the bridges that you cross, the port that handles your cargo are all safe from damage in these types of events.

Here’s the link to the USGS event summary, for those of you with interest:

http://earthquake.usgs.gov/earthquakes/eventpage/ci15481673#summary

Be safe, everyone.

La Habra Shake Map

14_03-Oso-8Here at Atlas World Headquarters we’re learning as much as we can about the circumstances leading up to the tragic Oso mudslide. Disasters like that are newsworthy in the US precisely because they are infrequent. We learned hard lessons about floods and fires in the early stages of settling the continent, before our population was so large and had decided to live so deeply in the wilderness. From those experiences, and with engineering input, we created regulations that, most of the time, protect most of the population from natural disasters.

The main problem with this American, reactive approach to safety regulations is that useful safety improvements almost always are adopted after a major disaster, when  death and destruction has already visited a community.  Seismic design provisions in the building code were finally considered after the 1906 San Francisco event, but weren’t adopted in California until 1933.  Double-hulled oil tankers after Exxon Valdez, inspect and repair your levees after Katrina, the pattern is obvious and tragic. In each case there are qualified experts, rational men of science, well aware that tragedy is only a matter of time but who are not taken seriously by the people’s representatives until the “likelihood” of disaster turns into a horrible certainty.

The Oso landslide follows this typical pattern. The hill across the river  is called Landslide Hill, for Pete’s sake. This landslide has expanded in six documented episodes since 1949 and almost certainly predates development in the area. Reasonable people could disagree whether the data foretold  an event like the one that occurred, a 2-stage rotational failure that forced a mudflow across the river to bury the neighborhood. The hazard was known but not with the certainty that could force land use changes that would have saved lives. Snohomish County approved building permits at houses that were plainly in harm’s way and are now under the mud, and the Washington DNR has permitted logging above the slide with only nominal and, likely, ineffective restrictions.

My consulting practice is showing signs that this will change. Sophisticated landowners are now considering the long-term benefits of incident avoidance as a method of slowing regulatory expansion. The political process is not orderly at the best of times and is particularly unpredictable in the face of disaster, when the non-technical electorate is demanding that “someone do something.” Hastily adopted, reactive regulations often overshoot the mark. Since the new regulations cover the entire industry, the entire state, the entire business operation, the cost of compliance usually far exceeds the cost of self-imposed operational improvements that might have avoided the incident and prevented the regulatory expansion.

At Oso, the landowner is a small forest resources company with very low profile, not the group you would expect to lead the industry in operational improvements. They cut timber because the regulations permitted it and they are in the business of cutting timber where permitted. The larger forest products companies in Washington, though, have adopted practices that may have prevented logging above a place called Landslide Hill. Their practices are unlikely, now, to be considered as Washington adopts new logging regulations.

Atlas works in a number of industries with such systemic regulated risk. Liquid and gas pipelines, rockfall, power plants, high-profile infrastructure with significant risk. We evaluate the whole cost of incidents, including natural hazard risk, as it affects our client’s reputation and their operational flexibility. An incident on your line, or even in your industry, has huge implications on new permit applications. The two main Canadian liquid petroleum pipeline operators are managing exactly this risk as they apply for major permits to move crude to market from Alberta. Those pipelines can be built and operated safely, and it would be nothing but bad luck if a small operator with a shoddy record had a preventable incident that, in the view of the non-technical electorate, gave the entire pipeline industry a black eye.

There are other aspects of the Oso disaster that bear further analysis, and we’ll organize our thoughts in a future post. For now, we hope that the responders stay safe through the difficult, muddy clean up, that the community recovers and the road re-opens, and that the forest products industry maintains its voice in the unavoidable evolution of Washington’s logging rules.

14_03-Oso-9

Oso Landslide Overview

For those of you with more interest, the AGU Landslide Blog has excellent technical coverage of this event.

http://blogs.agu.org/landslideblog/

The first hint of logging regulation changes that are, now, almost inevitable in Washington is here:

http://slog.thestranger.com/slog/archives/2014/03/27/is-there-a-connection-between-the-mudslide-and-our-states-historical-mishmash-of-logging-regulations

And those of you interested in model regulations would do well to be aware of Oregon’s excellent Forest Practices Act, which can be accessed here:

http://www.oregon.gov/odf/PUBS/docs/Forest_Facts/FF-LandslidesDebris%20Flows2013.pdf

 

One of the Atlas Crew  shared with us this fantastic bit of Corporate correspondence from the past.  I attach just the first (of two) pages below.  Let’s pause a moment for you to scroll down and bask in its magnificence.

As background, in 1922 F.P. Summers was Purchasing Agent for Standard Oil Company, with offices at 260 Bush Street in San Francisco. There are just so many interesting aspects to this, it’s hard to know where to start.  In no particular order:

  1. Yes, Purchasing always has, and always will, forever and ever, send department managers notes about profligate expenditures.  If they didn’t there would be no need for Purchasing. Save those notes, carve out a special place in your Corporate folder, and 91 years from now some hardworking engineer will unearth it and marvel at the smallness of corporate priorities.
  2. The exorbitant $32.85 in pencils that the Bakersfield refinery ran through in 1922 is now worth a cool $455.51 according to the CPI calculator.  Paltry compared with an Autocad upgrade, but honestly, that seems a little steep for a medium-sized refinery.  One wonders where all the pencils went?
  3. On the one hand, it is good to know that the Bakersfield refinery pencil expenditures didn’t bankrupt the company before the Great Depression, so that it could grow to global prominence, change its name to Chevron, and report 2013 earnings of $21.4 billion.  They can afford all the pencils they want now.
  4. On the other hand, maybe it is only because of F.P’s parsimonious management that the CEO now enjoys a seemingly permanent invitation to the World Economic Forum at Davos.  If so, we must examine our minor line items if our strategic plans intend global domination.
  5. Office Boy!?  Seriously, Office Boy?  Wow.   And I love how F.P. refers to that person as just “the boy.” What would a modern HR department make of that job title?   The memos would just be flying back and forth. All potential efficiencies that Purchasing expects from “the boy” and his mobile pencil sharpening service would be consumed by lawsuits.
  6. Any savings not litigated into extinction would be necessary to replace the lost pencil sharpener because it’s nailed to a board and not bolted to the wall.
  7. Can you imagine interviewing for that job?  “…And this is your pencil sharpening board…”  I like to imagine “the boy” as an office-bound Gunga Din, but with a pencil sharpener instead of a water skin, bravely sharpening while the Engineers wear down their points in glorious battle.

I didn’t share with you  Page 2, wherein F.P. offers pencil sharpening advice, task-based criteria for selection of proper hardness, praise for pencil holders, and a rather long discourse on “delivery wagon” drivers’ preference for the short stubs that, apparently, the wastrels in the Bakersfield refinery have been throwing away.

All in all, a delightful diversion for a cool and rainy afternoon.  I hope that you all enjoyed this little bit of classic pettifoggery. Drop me a note in the Comments if you’re interested in having a copy of the whole document.

Pencil Consumption 1922-23

We’re buried under a mountain of work here at Atlas Geotechnical World Headquarters, but you all know I advocate for action (or as our good friend Andreas says “MSH, man, make s*%# happen.”) One aspect of  busy times in the office is that always there remain nooks and crannies in your schedule for brief tasks.  So, I’ve been meaning to put this out to you all for some time, and now seems to be my best opportunity.

This post involves a bit of Bay Area folklore, a distilled version of the management philosophy of the seminal high-tech firm and it;s two founders who left an indelible mark on every discipline of engineering : Bill Hewlitt and Dave Packard. In 1935 both graduated with EE degrees from Stanford (the “junior university” across the tracks from Cal, from whence all good engineering emanates…). Despite these meager origins (joking – all in jest) four years later they formed a partnership that they named, by coin-toss, Hewlett-Packard. Their original premises were the 1-car garage at 367 Addison Avenue, Palo Alto. Their success at that location created the epicenter of what we now call the Silicon Valley.

Wikipedia tells the story better than I ever could: http://en.wikipedia.org/wiki/HP_Garage

The part of the story that I want to emphasize are the “Rules of the Garage.” I have no knowledge about how the Rules were developed or by whom. All I know is that these are the Rules, and that we all would do well to adhere to them.

garage 2

I suggest that you all follow the Rules.  They’re widely publicized because they work, and not just for high-tech startups (which is what HP would have been called if such a thing existed in 1939).  Of the 11, these are the three that I keep close to my heart:

1.  Believe you can change the world

4.  Share – Tools, ideas. Trust your colleagues.

7.  Radical ideas are not bad ideas.

Each of the Rules is important to your practice.  Customer satisfaction, innovation, collaboration.; these are the hallmarks of successful consultancy.  Clip that photo and refer back to it while you’re revising your strategic plan or deciding to branch out into new fields.  Positive and innovative thinking is crucial to success, and the Rules that Hewlett and Packard formulated for us are a  beacon on our roads to success.

More information about the actual structure and HP’s commitment to preserving the birthplace of Silicon Valley is here: http://www8.hp.com/us/en/hp-information/about-hp/history/hp-garage/hp-garage.html

Interesting thoughts about decision making from a large company that I admire.

Arup on Decision Making

Two observations:

1.  It’s so reassuring to see some firms spending time on these types of issues.  More like this, please.  And,

2.  The Arup blog has an “ethics” tag.  What insight does that offer, when a company has an ethics tag on their outward-facing media?  Sure, there are only 2 posts in that category, but that’s 2 more than most companies, let along companies of that size.  We are shamelessly copying that.