2008 i moved cable stayed br. lecture up. cable stayed has ... · a collection of menn bridges to...

2008 I moved cable stayed br. lecture up. Cable stayed has some Menn stuff in it but without the write context, they do not know ETH yet, they do not know the swiss story at all. So, the order is off they have already seen Sunniberg, but they don’t know why or who or how. need to fix that.

2012 I think Sunniberg is pulled from cable stayed and should come back here. but have not the time tonight to fix it.

A collection of Menn bridges to whet the appetite for exploring bridges today, then transition to Menn’s classic favorite.

14-01 landwasser viaduct_150dpi.jpg

We begin back in the Graubunden, Switzerland’s largest and least populous canton.This is the region where Maillart’s greatest works occurred and where, between 1957 and 1970, a new series of bridge forms would appear, crafted by the third of our Swiss structural artists, Christian Menn, a native of the Graubunden.Menn’s favorite structure in the canton is the landwasser viaduct, a stone structure of 1904 which essentially ends thousands of years tradition in the design of plain masonry structures. The bridge is light and elegant for its material and is free from extraneous decorationIt is also curved!!

http://www.myswissalps.com/graubunden/graubunden-vacation.asp?lang=EN

http://myswissalps.fileburst.com/maps/gr_s1720x1264_en.jpg

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The Graubinden has long been a draw for artists, especially picturesque mountain towns like Davos

Davos also functioned as a tuberculosis refuge for Europe. The mountain airs could cure you.

14-04 tavanasa bridge_150dpi.jpg

Nearby at Tavanasa we find Maillarts first masterpiec of the hollow box form

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Which we recall was destroyed by an avalanche in 1927.

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Maillart proposed designs for Tavanasa after 1927 avalanche destroyed original version..Along with several other possibilities of more standard arches.The top looks quite similar to the valtschielback which was completed two years priorAnd the bottom is also deck-stiffened, but with a different approach treatment, though still retaining unnecesasry heavy piers at the abutment.

14-09 tavanasa bridge_150dpi.jpg

Maillart lost the commission, but the actual bridge looks remarkably like his third design, except that the designer did not use the deck stiffness and so has an over heavy arch

14-09 tavanasa bridge_150dpi.jpg13-61 valtschielbach bridge_150dpi.jpg

Maillart lost the commission, but the actual bridge looks remarkably like his third design, except that the designer did not use the deck stiffness and so has an over heavy arch

photo SRA

It was in the next year, 1928 that Maillart won the commission to design and construct the Salginatobel

Where finally he completely frees himself from any vestige of stone tradtion.

His style in hollow boxes has matured

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The 1933 Thur bridge at Felsegg has an arch form which is broken at the apex.


This is due to heavy live loads at the site which made him desire a deeper section at the quarter points.


Greater width also led to lighter cross frames rather than the transverse walls of Salginatobel and multiple parralel hollow boxes

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In the Vessy bridgeof 1936, near Geneva, he used a very flat broken arch

14-16 bern railroad bridge_150dpi.jpg

And in a competition for a bridge at Bern he again altered the form tomore clearly express the hinges by moving them out into the span.

14-17 lachen bridge_150dpi.jpg

The 1940 Lachen Bruidge presents a more sculptural aspect because he used two hollow boxes to accommodate the skew crossing.

14-19 lachen bridge_150dpi.jpg

And as at the Bern proposal Maillart more clearly expresses the presence of the hinge.

14-20 garstatt bridge_150dpi.jpg

Finally, in 1940 at Garstatt, the arch is so altered that it in some sense ceases to be an arch

14-21 garstatt bridge_150dpi.jpg

But rather a form of two triangles. The goal is strucural : deeped quarter points, and constructural : easier formingThe bridge looks heavier, and perhaps even appears through illusion to bulge downward, and is not as visually effective as Vessy and Lachen.It illustrates the directions in which Maillart may have been thinking at the end of his life, flatter forms with fewer curves. Do these presage prestressed concrete forms?

14-22 soleri bridge proposal _150dpi.jpg

As Maillart was continuing to hone his designs, others were proposing essntially sculptural solutions to the bridge problem, such as this by Paolo SaleeriA tubular concrete form which would have been very wasteful of materials.

wikipedia: Paolo Soleri (June 21, 1919, Turin, Italy) is an Italian-American visionary architect with a life-long commitment to research and experimentation in design and town planning. He established Arcosanti and the educational Cosanti Foundation. Soleri is a distinguished lecturer in the College of Architecture at Arizona State University and a National Design Award recipient in 2006. [BWS note: Arcosanti is a sort of dense urban utopia vision, that actually exists outside of Phoenix]


We now spend a little time at VessyWe would like to illustrate how suprising and pleasing new forms can arise from the engineers creativity rather than from sculptural or architectural flights of fantasy.


Here Maillart attacked the one part of the bridge he had not yet truly innovated with, typical of his piece by piece approach, the cross wallsThe X-form here is suggested by his calculation, but not so dictated. The X-s mimic the bending moment diagram for the walls under side loads.

14-25 leipheim bridge_150dpi.jpg

Vessy is contrasted with the Leipheim bridge of 1937 which was an admitted copy of Maillarts three hinged style. The final form finding here was done by an architect, and the structure lacks the visual surprise of Maillart’s efforts.Even the details seem clunky

14-26 salginatobel crown hinge _150dpi.jpg

As we contrast Maillart’s very simply concrete hinge

14-27 leipheim crown hinge_150dpi.jpg

With a complicated metal insert used at Leipheim.

14-28 leipheim bridge section_150dpi.jpg14-29 vessy bridge section_150dpi.jpg

And the cross section at Leipheim is much heavier, by a factor of three

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Profiles of the structures demonstrate that the leipheim effort, while nice, is lacking (really? Vessy is pretty intense) True enough. This is not an obvious comparison, but nonetheless a good one for discussion.

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This form has deep symbolic affinity with the geometric creations of the painter Paul Klee

Who was, like Maillart, from Bern, and who had his studio in Bern at the same time Maillart was designin there

Klee was deeply involved with buildings, having taught at the German Bauhaus in the 1920’s

He died in the same year as Maillart, 1940

wikipedia: Paul Klee (IPA: kleː) (December 18, 1879 to June 29, 1940) wasa Swiss painter of German nationality.[a] He was influenced by many different art styles in his work, including expressionism, cubism and surrealism. He and his friend, the Russian painter Wassily Kandinsky, were also famous for teaching at the Bauhaus school of art and architecture. Today (2007), a painting by Paul Klee can sell for as much as $7.5 million. A museum dedicated to Paul Klee was built in Berne, Switzerland, by the

Italian architect Renzo Piano. It opened in June 2005 and houses a collection of about4000 works by Paul Klee.

14-37 salginatobel bridge scaffolding_150dpi.jpg

Meanwhile, as the scaffolding was up at salg. A mathematics teacher in the town which sponsored the bridge, Schiers, decided to leave his school and study himself, to become a civil engineer

14-38 pierre lardy_150dpi.jpg

He earned a Doctorate at ETH, and it is thus that, in 1945 Pierre Lardy became next in the line of great teachers at ETH, in the tradition of Culmann and Ritter.At ETH Lardy would train a remarkable run of students, among them Christian Menn and Heinz Isler, who would become premier structural artists in the same way that Ammann and Maillart did from Ritter a generation earlier

14-39 salginatobel bridge_150dpi.jpg

Menn first learned of Maillart and his designes from Lardy and would mimic his forms in his early bridges.Salg would be a model for

14-40 letziwald bridge_150dpi.jpg

Menn’s Letziwald bridge of 1960

14-41 klosters bridge_150dpi.jpg

And Klosters for

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Menn’s own deck-stiffened effort at Crot in 1960

Menn’s early work was all in his home canton of the Graubunden

14-43 waltschielbach bridge_150dpi.jpg

Where we also find valt.

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And Menn’s crestiwald, seen here undergoing a load test, or a traffic jamThe traffic jam here is caused by Swiss army artiller practice

14-47 valtschielbach bridge_150dpi.jpg

And deems it worthy of his complete trust despite its fifty years of Swiss winters

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Neaby again is the Crestiwald bridge of Menn

14-49 reichenau bridge scaffolding_150dpi.jpg

And the scaffolding of the first of his 100 meter spans, the Reichenau

SGB to BWS: “It is a photo of a framed picture. Reflection from glass. It is in The Development of the Long Span Bridge by Tom Peters and others published by ETH based on an exhibit circa 1979.”

14-50 reichenau bridge_150dpi.jpg

Similar form, but not lengthening in span!

Seen here as completed in 1964 span 98 metres compare salg 89 metres, tavanasa 51 metres


Similar form, but not lengthening in span!Seen here as completed in 1964 span 98 metres compare salg 89 metres, tavanasa 51 metresNarrow polygonal, widely spaced verticals


With a roadway curved only at the approaches. (recal Valtschielbach vs. Schwandbach)


Here we see high up on the arch the holes which are there two receive the dynamite to destroy the bridge should the countrybe invaded.All Swiss bridges and tunnels are so equipped, the thinking being that the Swiss will have a natural advantage in the hard to travel mountains without proper roads.


The verticals at Reichenau can be more widely spaced because of the advent of presetressing, and the savings is in labor costsThe decks are themselves hollow box prestressed concrete girders (the hollow box and the deck stiffener arch combine!)This sparse design allows arches of very great thinness, and decks which are themselves lighter than Maillart’s RC designs as we see here in the Nanin and Cascella bridges of Menn also in the Graubunden.

14-57 the palace at 4am by albert giacometti_150dpi.jpg

One can perhaps envision a connection to the sculptures of Alberto Giacometti who also prized lightness

Unsursrisingly, Giac. Is from the Graubunden, where the landscape itself is sparse

wiki: Alberto Giacometti (October 10, 1901 – January 11, 1966) was a Swiss sculptor, painter, draftsman and printmaker

14-58 salvanei bridge_150dpi.jpg

And where Menn’s Salvanei bridge seems to fit well with the landscape

14-59 felsenau bridge_150dpi.jpg

In 1970 Menn won an international competition for a crossing of the Aare river outside of Bern

14-60 felsenau bridge section_150dpi.jpg

He designed a prestressed concrete, hollow box cantilever for the Felsenau crossing

14-61 cantilever girder design_150dpi.jpg

The shape of which is influenced again by the shape of the bending moment diagram of a cantilever.

14-62 felsenau bridge prestressing tendon layout_150dpi.jpg

Here we see in red the prestressing tendons, more of which are necessary near the supports, where moment is highest

14-63 felsenau bridge scaffolding_150dpi.jpg

As the cantileverd bridge marches across the valley,

14-64 revolution of the viaducts by paul klee_150dpi.jpg

We might be reminded of another Klee work, the revolution of the viaducts

14-65 felsenau bridge construction_150dpi.jpg

In the hollow box under construction we see the plain reinforcement and the conduits to hold the prestressing tendons.

14-66 christian menn at felsenau bridge construction_150dpi.jpg

Herr Menn is there overseeing the work looking out on his creation

14-67 felsenau bridge construction_150dpi.jpg

And now the cantilevers have almost met in their progressing construction.

14-69 felsenau bridge_150dpi.jpg

The completed bridge shows the evolution of the prestressing idea from the plain boxes of Finsterwalder etc.Here Menn takes the single hollow box, and makes it deeper but narrower at the piers to lend stability. The resulting is a 3D interplay of shapes which makes the structure attractive.note also the two walled towers rather than hollow box.Als deck is cantilevered out from the hollow box

14-70 landwasser viaduct_150dpi.jpg

In perhaps a similar way to Menn’s favorite structure, the landwasser viaduct.

This example of remarkably light use of stone in the Graubunden and its great sculptor

14-71 tall figure by alberto giacometti_150dpi.jpg

Giacometti, who was able to minimize even the human form in some of his work

14-72 alberto giacometti_150dpi.jpg

14-73 ganter bridge model_150dpi.jpg

Menn’s Ganter bridge completed in 1980 illustrates how a striving for efficiency and economy can lead to entirely new forms in structural art

14-74 ganter bridge construction_150dpi.jpg

Not only is the final form striking, but the bridge under construction presentd an interesting profile to the countryside during the three year construction


Strange forms seem to emerge from the woods


Being supported only by a light scaffold and seeming to reach towards one another

photo SRA

And finally reach, giving us a brand new form in Presetressed concreteThe stays are there to shorten the cantilever spans, whichg would have been much longer than FelsenauThe tall tower is due to local conditions which provided the only solid bedroxk thereThe roadway is curved so the stays need to be encasedThe towers are hollow boxes due to height, but very widely spacedMenn wanted something above the roadway to balance the aesthetics

photos SRA

While the profile is striking, the interior views of the structure are perhaps alarming

photo SRA

As the curious triangular walls/stays present a strange perspective.

As with all great bridges, different perspectives provide different views, not all of which are equally light at all times.

photo SRA

The valley has been altered by engineering, whether for the better or worse is for you to decide, but for a road I think we did not badly here

14-82 ganter bridge_150dpi.jpg

14-83 salginatobel bridge_150dpi.jpg

Menn realized that he had actually buitl a Maillart bridge upside down, having earlier copied him right side up

14-84 ganter bridge_150dpi.jpg

Perhaps thegreatest of compliments

This need to move somewhere closer to Menn...

http://is-beton.epfl.ch/Photos/Small/I/I34/I34-12.jpg

Chandoline over the Rhone 1989 – C. Menn

140m main span, slight horizontal curvature necisstitated the out-of-plane stays at the ends.

All concrete – including concrete trussing of deck

Tower/mast shape interesting but logical?

The epiloge is that Ganter inspired Menn to investigate cable stayed forms further such as here at Sunniberg

photo SRA

photo SRA

Ben: the towers are quite low, the cables quite vertical – what is the difference between low and high towers? A horizontal cable is pre-stressing – a cable going to a tower is cable-stayed... Where is the dividing line?

IABSE article

JSE Billington article

Pier, pylon, cables, and deck each designed to satisfy technical requirements and aesthetic requirements.

Pier(below road), pylon(above road): pier and pylon are integrated. Pier shape expresses the pier bending demands for live loading on one span.

Pylons are flared: (1) visually interesting, (2) allows cables to remain straight as deck curves (3) resists bending due to curvature for LL on 1 span

Cables: low slung = high tension, deck thickened near piers to resist compression there.

Deck: continuous thin line, no expansion joints, breathes laterally as needed

In the same valley as Salginatobel.

photo SRA

mentioned briefly in the sable-stayed lecture we touchdown in Boston again briefly to see how Menn’s ideas faired in this situation

http://www.deuring.ch/christian-menn/english/projekte_e/zakim_e.htm: “The new Leonard P. Zakim Bunker Hill Bridge is the only one of its kind ever built. In addition to being the widest cable-stayed bridge in the world, the bridge will be the first "hybrid" cable-stayed bridge in the United States, using both steel and concrete in its frame. The main span consists of a steel box girder and steel floor beams, while the back spans contain post-tensioned concrete.”

lost in translation??

photo SRA

Engineering is always creative, otherwise it is not engineering. – troyano recently compiled a tome on bridges

14-85 marie-claire blumer maillart with christian menn_150dpi.jpg

Here is Menn describing something to Maillart’s daughter on the bridge looking good

14-86 robert maillart with cigar_150dpi.jpg

One wonders what the old genius would have thought

Give some time at the end of class to start organizing groups. Also try to ease their fears about group work.

The epiloge is that Ganter inspired Menn to investigate cable stayed forms further such as here at Sunniberg

And here in Boston. About which more later

Edited by SRA 05

14-28 leipheim bridge section_150dpi.jpg

And the cross section at Leipheim is much heavier, by a factor of three

14-29 vessy bridge section_150dpi.jpg

14-49 reichenau bridge scaffolding_150dpi.jpg

And the scaffolding of the first of his 100 meter spans, the Reichenau

SGB to BWS: “It is a photo of a framed picture. Reflection from glass. It is in The Development of the Long Span Bridge by Tom Peters and others published by ETH based on an exhibit circa 1979.”

2008 i moved cable stayed br. lecture up. cable stayed has ... · a collection of menn bridges to...

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