Posted in Civil Engineering

The Zubizuri Bridge, Bilbao, Spain

Construction and architecture

TheZubizuri(Basquefor “white bridge“), also called theCampo Volantin BridgeorPuente del Campo Volantin, is atied archfootbridgeacross theNervion RiverinBilbao, Spain. Designed by architectSantiago Calatrava, the bridge links theCampo Volantinright bank andUribitarteleft bank of the river.

Opened in 1997, the bridge’s unusual design consists of a curved walkway which is supported by steel suspension cables from an overhead arch. The structure of the bridge is painted white and the bridge deck consists of translucent glass bricks. Access ramps and stairways are located on both banks.

The Zubizuri offers pedestrians a convenient route from hotels to the nearbyBilbao Guggenheim Museum.

Since its opening, it has been subjected to praise as a symbol of the new Bilbao and as a draw for tourism. Architectural professor Alexander Tzonis wrote:[

“The intelligence, vitality, and originality of the bridge’s…

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Posted in Civil Engineering

Lessons from the Cotter Bridge

The Ruthven Bridge, as it has been officially called since 1976, is a familiar landmark to visitors and residents of north central Arkansas.  It has an interesting history, not only for its design and construction, but also in how it was authorised and its subsequent history.

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Arkansas did not establish a State Highway Department until 1927.  Before that time the counties were responsible for building and maintaining the roads.  One of the Department’s first tasks was to identify places where major bridges needed to be built.  One of those sites was the White River at Cotter, west of Mountain Home.  (It’s the same White River, and not far from the site, of the real estate development that the Clintons made famous in the Whitewater scandal.)

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Unfortunately the State Highway Commission had put the bridge at Cotter at the bottom of the list.  This was remedied by Judge R.M. Ruthven, who pocketed the report before the Commission met.  Unaware of the priorities of the report, the Commission approved the bridge and construction began.

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The bridge was designed by James Barney Marsh, who used a patented design for this reinforced arch bridge.  The rainbow concrete arch bridge was meant to be an economical substitute for the steel arched bridges at the time, and had the added advantage of being more corrosion resistant.  In addition to the novel design, the bridge was built by first putting in place the steel arch reinforcement and then using that to hang the forms and pour the concrete for the rest of the bridge.  This eliminated the use of formwork built from the river bed; the White River’s wild swings in level made that a risky proposition.  (Today bridges across rivers and wetlands are generally built from the top down for environmental reasons.)

The bridge was completed in 1930.  It eliminated significant detours during flooding; the next bridge crossing was upriver at Branson, 100 miles away.  One would think that such an improvement would have been welcome, but traffic was low because the locals preferred to use the ferries, which were paid ferries and slower.  The State Highway Department found this frustrating; one highway engineer stated that “If Baxter County people want to new improvements on their highways, they will have to patronise those already made…”  The Department was not at a loss for a fix: they paid off the ferry operators to get out of business, the last one for USD250.00.  With that traffic picked up, and it remained the main crossing between Baxter and Marion counties until the 1980’s.

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It’s strange that, in these days of “free stuff” most systems, religious and secular, need a payment.  Beyond the usual griping about taxation, we pay a great deal of “rent” for many things: housing, Internet and data service, utilities, and the like.  Most religious systems are this way.  They require that we do certain things to get a temporal or eternal reward.

Christianity has never been like this because Jesus Christ paid the price for our sin on the Cross.  “The Divine Righteousness which is bestowed, through faith in Jesus Christ, upon all, without distinction, who believe in him. For all have sinned, and all fall short of God’s glorious ideal, But, in his loving-kindness, are being freely pronounced righteous through the deliverance found in Christ Jesus.” (Romans 3:22-24, TCNT.)  That work is complete.  We don’t have to pay the ferry operator anything to get from this side of eternity to the other.  In fact, like the residents of north central Arkansas, we don’t have to take the ferry; the bridge was built and paid for.  “But, when Christ came, he appeared as High Priest of that Better System which was established; and he entered through that nobler and more perfect ‘Tabernacle,’ not made by human hands–that is to say, not a part of this present creation. Nor was it with the blood of goats and calves, but with his own blood, that he entered, once and for all, into the Sanctuary, and obtained our eternal deliverance.” (Hebrews 9:11, 12, TCNT.)

Many of you—and I know this was an issue in my own family—have been trying to get to where you want to go by paying something, whether money, time (think about all that “volunteer” work you’ve done to pad your resumé) or whatever.  But the most important destination can be had for free; the choice is yours.

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Most of the material for this piece came from Witcher, T.R. (2016) “Arkansas’ R.M. Ruthven Bridge.”  Civil Engineering, July/August, 42-45.  The photos are mine.

Posted in Soil Mechanics

Soils in Construction (Sixth Edition) Now Available

It’s here a last: Soils in Construction, the Sixth Edition, now available from Waveland Press.

Many of you (and especially those who are familiar with the companion site vulcanhammer.info) are aware that I’ve spent much of my career in geotechnical engineering and deep foundations dealing with contractors.  As such I am both sympathetic with their situation and also aware that they need good information to make decisions that can “make or break” a job or their company.  It was for that reason and more that I was very happy to be invited to co-author the Fifth Edition fifteen years ago and to help prepare this revision as well.

Soils in Construction is designed to teach the basics of soil mechanics and foundation design to construction management students and to be a reference for those “in the field.”  It takes a practical approach to the subject, and it also deals with “temporary works” such as dewatering and cantilever sheet pile walls that many design engineers are unfamiliar with.

There will be more resources for this book available, both from Waveland Press and on this site as well; I’ll keep you posted.  Waveland has been great to work with and I appreciate the effort they have put into the book.  But the one person I want to say special thanks to is Lee Schroeder, Professor Emeritus (and former Interim Athletic Director) at Oregon State University.  Eminent in his own right outside of the book (he’s the Schroeder of the Schroeder-Maitland method for cellular cofferdams,) his vision for the original work, his practical and experienced implementation of same, and his graciousness and support in allowing me to be a part of this project are deeply appreciated.

You can order the book (and for you academics, request an evaluation copy) here.

 

Posted in Academic Issues

Advice to Graduates: Past Performance is Not a Guarantee of Future Returns

It’s the time of the year when most people graduate from whatever school they’re graduating from.  This is a hypothetical graduation address, aimed a college students.

These days college–especially undergraduate studies–is a long, expensive undertaking, usually accomplished by a large amount of debt.  (Come to think of it, what in our society is accomplished without a large amount of debt?)  And yet, in spite of the long-term obligations that come with it, people continue to put a great deal of stock and effort in a college education.  Why is this?  Most of you know the answer: because jobs and careers opened up by a college education have a higher level of compensation than those that don’t, at least overall.  College seen in this way is an investment, and I’ll come back to the financial analogy.

One thing I’ve noticed while walking the halls of Old Kudzu (“Old Ivy” is more appropriate for places Up North which are not appropriate to speak about here) is the “first in family” thing about college.  There’s a great deal of emphasis on those people who have broken the multigenerational custom of living and dying for a college athletic program without having stepped foot on campus except to head to the football stadium.  As you would expect, an elitist snob like me doesn’t have that experience.  I come from a long line of “college men” whose main problem wasn’t going to college: it was getting to the place you’re at today, i.e., graduating.  Today that’s another obsession of our educational system.  We’re told that our graduation rates are too low, with the implication that those who don’t walk the stage don’t walk the golden path of success in life.  But somehow my ancestors were successful in spite of that fact.

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One that actually did make it to the end was my grandfather, Chester H. “Chet” Warrington, who graduated–after giving his parents much heartburn–from Lehigh in 1912. He’s there on the right, before he actually made it through.

Even though he graduated from the birthplace of Tau Beta Pi, engineering’s highest honour fraternity, he wasn’t much of a scholar.  There have been many changes in the whole meaning of a university education from his day to ours, and one of them is how much more competitive our system–in and out of academia–has become.  In those days college was largely the province of the well-heeled, and the “Gentlemen’s C” was not a dishonourable result.  (I would say that the “Gentlemen’s C” is still very much alive and well on campus today, in spite of the changes!)

But we, as we do with just about everything, have pushed the whole business of academic achievement to the limit.  It’s surely frustrating to most academics that people who aren’t very good students actually have a successful life in this world, as my grandfather had.  It’s even more frustrating that, after all of the glow people put around academia, the money goes elsewhere.  So we’ve had a drumbeat, of late, of how important it is for people to have very high grades, and to correlate (at least in our minds) those high grades with success in life, and ultimately to try to rig the system so that those who do well in an academic setting will be afforded similar success afterwards.

But life neither starts or ends on campus.  And sometimes the reality of life wedges its way onto campus.  A good example of that happened in one of my classes last year, and the life lesson it taught bears repeating.

One of the courses I teach is Foundations.  First question some ask is “Foundations of What?” There are many “foundations” courses on campus to introduce students to a wide variety of subjects, but mine is the Foundations course par excellence: it concerns the design of foundations for real structures such buildings, bridges and the like.  This past year my students convinced me, for their design project, to enter the American Society of Civil Engineers MSE wall contest.  An “MSE” wall, for the uninitiate, is a Mechanically Stabilised Earth wall.  If you’ve driven down the interstate and seen newer walls flanking the roadway, usually with fancy decorations, you’ve probably seen an MSE wall.  The fancy decorations, however, have nothing to do with that: behind the front of an MSE wall is a network of grids and meshes by which the earth behind the wall actually helps to hold it up rather than just trying to push it down.

In this competition, the students build a large wooden box with a removable face.  They then put an MSE wall entirely built of kraft paper and tape behind it and fill the box with sand.  Removing the face, the moment of truth comes when the wall either holds the sand in place, leaks a great deal of sand, or collapses with sand on the floor following.

The class divides itself into two teams, using an electronic sign-up system.  When the team compositions were finalised, the “buzz” around the class was that one team was made up of the “smart” people and the other wasn’t.  I was unconvinced that it was that rigged; years in the private sector and engineering practice gave me the gut feeling that the outcome would not follow the conventional wisdom.

It didn’t.  When the removable panel was in fact removed, both walls held, but the “smart” team had the scarier moment as their wall bulged and leaked considerably.  Conventional wisdom took another hit.  But the whole point of an educational system is to learn something, and there’s a good lesson here.

There’s a great deal of emphasis on the value of intelligence these days.  It’s almost an obsession, really, and permeates our whole system, from child rearing to the educational system itself and ultimately to the credentialling system that marks the road to the top.  Raw intelligence, however, is only one piece of the puzzle.  That intelligence has to be properly applied to achieve the best results, and that application includes two things: an understanding of the environment in which you’re operating and the willingness to put the effort in to attain the goal.  Those two elements are frequently lacking, and I speak from experience: the lack of those two elements have led to many of the mistakes I have made in life.  Although there’s a great deal of talk about including “real life experiences” in an academic course, to be honest time constraints and the same lack of understanding in academics lead many such efforts to fall flat.

Even with the political clout that our financial system has these days, it’s still necessary for those selling financial products to make this disclaimer (or one like it): “Past Performance is Not a Guarantee of Future Returns”.  I think that should be placed somewhere, or at least watermarked, on every diploma issued by institutions of higher education.  Those of you who have finished the course of study can be justifiably proud of what you have done.  But you and the society you live and move and have your being in need to understand that what you’ve done isn’t a guarantee that what you do subsequently will have the golden touch.  The society that believes that and promotes accordingly is itself heading for a fall.  It was the hard lesson that Ch’ing Dynasty China found out the hard way the century before last; we will follow suit if we do likewise, our fall being at the hand of the same Chinese (with others) who did learn the lesson.

Graduation is a time of celebration, but, as the Latin root notes, it’s just another step in life.  The education doesn’t stop here, and by that I don’t mean the continuing education requirements that permeate our professional credentials.  Making the education work is the new task, and in many ways it’s as important–if not more important–than the first.