It's been a long time since I've done a bridges news roundup, so I'm going to keep most of these links short and sweet.
COBE, COWI and DISSING+WEITLING Wins Competition to Design 225 Metre Pedestrian Bridge for Køge
"Functioning as a solar screen on the south, pedestrian bridge opens to the city and provide panoramic views to the north."
Bouncy Squibb Park Bridge Closed For Being Too Bouncy
"It was designed to bounce (similarly to trail bridges in the woods) ... its movements had substantially increased, causing concern. It also started to tilt and sag in sections."
What a FAN-tastic design! Engineers create London footbridge that unfolds like a paper concertina
National newspaper in "gives credit to engineers" shock!
Footbridge Ribja brv / Arhitektura d.o.o
"Our aim was to design a bridge that has a construction as thin as possible, and bridge railing as transparent as possible."
Skyttelbron Bridge / Metro Arkitekter (Sweco Architects)
"The first idea, and perhaps the strongest in terms of design is that we wanted to bring color in an environment where virtually everything is in shades of gray, brown or green."
Bridge Over the Rhone / Meier + Associés Architectes
"This unity of form 'strides' over irregularities in the terrain and interacts logically with the location by progressively increasing its span in line with the mathematical principle of harmonic curves."
Floating bridge by RO&AD crosses the moat of a Dutch fortress
"The new 80-metre-long bridge follows the original route boats would have taken between a jetty on the edge of the moat and a raised entrance situated in one of the fortress's walls."
Must have a head for heights! London's Tower Bridge unveils £1m glass walkway 140ft above River Thames... costing just £9 to visit
"The pedestrians milling about on the pavements look as if they have come to life from a Lowry painting and there is nothing between them and my boots but a sheet of glass."
What Montreal’s All-New Champlain Bridge Should Look Like
"A peer of Taillibert, fellow architect Pierre Briset, is not confident in Taillibert's proposal. Briset believes Taillibert's plan is just a ripoff of the Millau Viaduct in southern France."
Calgarians celebrate bridge opening
"At a cost of $25 million, the span took five years to complete, one year longer than anticipated after the first bridge deck was destroyed in the 2013 flood."
Designer of Verrazano-Narrows Bridge: Low-profile genius preferred anonymity
"The greatest monuments to pioneering structural engineer Othmar H. Ammann are the ever-spectacular bridges born of his brilliance."
Léon Blum Viaduct Bridge / RFR
"We have chosen to create a structural continuity between the bridge deck and its vertical supports which are articulated at their base. In doing so, the area of the bridge which is most directly in contact with the town is freed from the kind of massive support commonly associated with this type of Bridge."
19 November 2014
18 November 2014
Danube bridge competition winner announced
Marc Mimram has beaten seven other teams to design a new €60m highway and tram bridge over the Danube in Linz, Austria. The other competitors included heavyweights such as Leonhardt Andra, Flint and Neill, Knight Architects, Dietmar Feichtinger and Dissing + Weitling.
It's a big bridge, some 30m and 400m long in total, and it's perhaps surprising to see a winner which is an essentially entirely new type of bridge. Essentially, it's a steel cantilever bridge along the lines of the Forth Railway Bridge, but with a number of unusual features.
The cantilever trusses are curved rather than comprised of straight pieces, requiring significant quantities of additional steel to resist the local bending induced in the steelwork. Very limited support is provided to the deck, which therefore has to be excessively deep.
The oddest feature, however, is the fact that the cantilevers sit on single lines of bearings, so that under uneven loading, the only stability is provided by the connection between adjacent cantilevers. Those short connection pieces don't really look stiff enough to provide that stability, and I wonder quite how the engineer has persuaded the design to work.
Of the other designs, the 4th prize entry is the most ambitious, with what appears to be a 250m span network arch bridge (just shy of the existing longest span of this type), a very challenging and complex structure to build.
Winner - Marc Mimram
2nd Prize - Öhlinger+Partner ZT GesmbH, Ponting Consulting Engineers and Zeininger Architects
3rd Prize - Gruppe VCE Vienna Consulting Engineers ZT GmbH, FCP Fritsch, Chiari&Partner ZT GmbH and Quist Wintermans Architects
4th Prize - SSF Ingenieure AG, ISP ZT GmbH and Knights Architects
It's a big bridge, some 30m and 400m long in total, and it's perhaps surprising to see a winner which is an essentially entirely new type of bridge. Essentially, it's a steel cantilever bridge along the lines of the Forth Railway Bridge, but with a number of unusual features.
The cantilever trusses are curved rather than comprised of straight pieces, requiring significant quantities of additional steel to resist the local bending induced in the steelwork. Very limited support is provided to the deck, which therefore has to be excessively deep.
The oddest feature, however, is the fact that the cantilevers sit on single lines of bearings, so that under uneven loading, the only stability is provided by the connection between adjacent cantilevers. Those short connection pieces don't really look stiff enough to provide that stability, and I wonder quite how the engineer has persuaded the design to work.
Of the other designs, the 4th prize entry is the most ambitious, with what appears to be a 250m span network arch bridge (just shy of the existing longest span of this type), a very challenging and complex structure to build.
Winner - Marc Mimram
2nd Prize - Öhlinger+Partner ZT GesmbH, Ponting Consulting Engineers and Zeininger Architects
3rd Prize - Gruppe VCE Vienna Consulting Engineers ZT GmbH, FCP Fritsch, Chiari&Partner ZT GmbH and Quist Wintermans Architects
4th Prize - SSF Ingenieure AG, ISP ZT GmbH and Knights Architects
17 November 2014
Heatherwick's Garden Bridge gains planning consent from Lambeth Council
Love it or loathe it, the world's most expensive pedestrian bridge has now secured half of the planning consent that it needs to go ahead. Of course, I loathe it. It's an utterly disgraceful waste of public money in a location which doesn't need another tourist attraction, nor need to be the site of a bridge which would permanently wreck the London riverscape.
As with the ill-fated River Wear Crossing in Sunderland, public opinion has been consistently misrepresented by its backers. Other than one or two people involved with the design team, I've not met a professional bridge designer who likes it. The architecture critics see it for the white elephant that it is. Even London's mayor doesn't quite see why he's spending public money on it. A highly critical and cogent campaign against it by local residents seems to have fallen on deaf ears.
What's clear about the Garden Bridge is how the cult of celebrity provides a comfort blanket allowing people to suspend their normal critical faculties. It's got Heatherwick, it must be good. Joanna Lumley likes it. It seems clear that, short of hoping for the bridge to fail to secure the necessary funding or to come in way over-budget once it reaches construction tender stage (both being quite realistic possibilities of course), the only way to put a stop to this fiasco is for the designers themselves to wake up to the realities of their iconic fantasy, do the decent thing, and quit.
15 November 2014
French Bridges: 7. Pont du Gard
This is the final bridge in this series of posts about the bridges of southern France.
What can I say about the mighty Pont du Gard, justly the most famous of the surviving Roman aqueducts, a magnificent bridge, a World Heritage Site, a gorgeous, golden-hued monument to the achievements of antiquity?
I'll try to avoid the obvious: there are plenty of websites and books, linked at the bottom of this post, which will tell you all you need to know about how big it is, when it was built, and why.
A few thoughts:
The site of the bridge is well looked after. An exhibition is tucked well away from the river gorge, and a cafe and restaurant are both a discrete distance away from the bridge. It's a great spot to picnic, and to swim in the river.
The arches on the lowest tier are each built in four parallel sections, and those of the middle tier in three parallel sections, all without any mortar (only the top tier was built with mortar). I noted the same feature at the Pont d'Avignon, and presumed it allowed the builders to reuse the timber centering multiple times. That first ring of massive stone blocks would have felt pretty precarious, though. Paillet's paper on the bridge (linked below) suggests instead that the centering was for the full width of the bridge, and the parallel sections were just adopted to simplify the size of blocks that the masons had to be cut, making all the voussoirs identical. I'm not entirely convinced by this argument.
There are a multitude of projecting stones on both the side faces of the bridge and the support piers, but also, more unusually, within the arch barrel itself. These were normally used on arch bridges to provide support to the temporary timber centering. I don't think I've ever encountered corbels in the arch barrel itself before. Is this a common feature on Roman bridges?
The lowest tier of the bridge was extended in the mid-18th century, creating a new highway bridge parallel to the Roman bridge and butting up against it. Some effort was made to make this similar to the older bridge, but the stonework is very different, as are the cutwaters. Most noticeably, the old bridge is level, but the new bridge is ramped up towards its centre point, seriously spoiling the appearance of the bridge from both sides. It's no surprise that most "postcard" views of the bridge are therefore taken from the unaltered elevation.
More positively, the extension bridge does allow people to appreciate the monument from close up, without exposing it to the deterioration that would inevitably result if large numbers of people were encouraged to clamber upon it.
Further information:
What can I say about the mighty Pont du Gard, justly the most famous of the surviving Roman aqueducts, a magnificent bridge, a World Heritage Site, a gorgeous, golden-hued monument to the achievements of antiquity?
I'll try to avoid the obvious: there are plenty of websites and books, linked at the bottom of this post, which will tell you all you need to know about how big it is, when it was built, and why.
A few thoughts:
The site of the bridge is well looked after. An exhibition is tucked well away from the river gorge, and a cafe and restaurant are both a discrete distance away from the bridge. It's a great spot to picnic, and to swim in the river.
The arches on the lowest tier are each built in four parallel sections, and those of the middle tier in three parallel sections, all without any mortar (only the top tier was built with mortar). I noted the same feature at the Pont d'Avignon, and presumed it allowed the builders to reuse the timber centering multiple times. That first ring of massive stone blocks would have felt pretty precarious, though. Paillet's paper on the bridge (linked below) suggests instead that the centering was for the full width of the bridge, and the parallel sections were just adopted to simplify the size of blocks that the masons had to be cut, making all the voussoirs identical. I'm not entirely convinced by this argument.
There are a multitude of projecting stones on both the side faces of the bridge and the support piers, but also, more unusually, within the arch barrel itself. These were normally used on arch bridges to provide support to the temporary timber centering. I don't think I've ever encountered corbels in the arch barrel itself before. Is this a common feature on Roman bridges?
The lowest tier of the bridge was extended in the mid-18th century, creating a new highway bridge parallel to the Roman bridge and butting up against it. Some effort was made to make this similar to the older bridge, but the stonework is very different, as are the cutwaters. Most noticeably, the old bridge is level, but the new bridge is ramped up towards its centre point, seriously spoiling the appearance of the bridge from both sides. It's no surprise that most "postcard" views of the bridge are therefore taken from the unaltered elevation.
More positively, the extension bridge does allow people to appreciate the monument from close up, without exposing it to the deterioration that would inevitably result if large numbers of people were encouraged to clamber upon it.
Further information:
- Google maps / Bing maps
- Wikipedia
- Structurae
- Official website
- UNESCO World Heritage list
- Athena Review
- Bridges: Their Art, Science and Evolution (Whitney, 1929)
- Bridges and their Builders
(Steinman and Watson, 1941)
- Bridges
(Dupre, 1997)
- Réflexions sur la Construction du Pont du Gard (Paillet, Gallia, 2005)
- The Pont du Gard: the Site and the Large Exhibition (Moreaux, 2005)
12 November 2014
French Bridges: 6. Carpentras Aqueduct
I leave Avignon behind now, for two final bridges from the south of France.
The aqueduct at Carpentras is a magnificent structure. It was built over a 14 year period, beginning in 1720, to the designs of local architect Antoine d'Allemande with Jean de Clapiès, to carry water from the north into the city. De Clapiès seems to have been an interesting fellow, a Director of Public Works but also an astronomer and professor of mathematics.
The structure has 48 masonry arches, 729m long in total, and up to 23m tall. At its top, it is only 1.75m wide, and carries a channel a mere 0.25m in width.
The aqueduct no longer supplies water, but survives as a historic monument. The main line of arches is impressive but also quite unusual, with an enormous taper to the piers, well beyond what is required for stability.
The most interesting features of the viaduct are at its southern end, where the aqueduct changes direction and is combined with a lower-level structure, suitable only to carry foot traffic. This part of the viaduct spans the River Auzon, and the spans are larger and made architecturally more prominent. The footway spans step out around the pier legs for the taller aqueduct, carried in part on little squinch arches.
I love this bridge both for its magnificence and its idiosyncrasy.
Further information:
The aqueduct at Carpentras is a magnificent structure. It was built over a 14 year period, beginning in 1720, to the designs of local architect Antoine d'Allemande with Jean de Clapiès, to carry water from the north into the city. De Clapiès seems to have been an interesting fellow, a Director of Public Works but also an astronomer and professor of mathematics.
The structure has 48 masonry arches, 729m long in total, and up to 23m tall. At its top, it is only 1.75m wide, and carries a channel a mere 0.25m in width.
The aqueduct no longer supplies water, but survives as a historic monument. The main line of arches is impressive but also quite unusual, with an enormous taper to the piers, well beyond what is required for stability.
The most interesting features of the viaduct are at its southern end, where the aqueduct changes direction and is combined with a lower-level structure, suitable only to carry foot traffic. This part of the viaduct spans the River Auzon, and the spans are larger and made architecturally more prominent. The footway spans step out around the pier legs for the taller aqueduct, carried in part on little squinch arches.
I love this bridge both for its magnificence and its idiosyncrasy.
Further information:
10 November 2014
French Bridges: 5. Rhone Railway Bridge, Avignon
I can tell you almost nothing about this bridge. It's just a big viaduct which carries the railway across the River Rhone at Avignon.
It lies relatively close to the water, and so gives some idea of the river's scale. At this point, the river is about 450m wide, and the bridge totals about 560m long, as it also spans highways and flood defences on both banks. Each individual span is about 75m.
The bridge is brilliant in its single-mindedness, comprising braced steel lattice truss girders unvarying in height, supported on masonry piers within the river. There's often something exquisitely beautiful about a bridge which appears to make no concession to beauty.
The most visually interesting feature of the bridge is surely one which was unintentional. The latticework on the trusses uses large diagonal elements which are formed out of steel angles. These inevitably create a pattern of light and shadow on the face of the girders. The arrangement has been alternated between spans, so that on a sunny day, each span of the bridge appears to alternative between a dark and light colour (third photo below).
Further information:
It lies relatively close to the water, and so gives some idea of the river's scale. At this point, the river is about 450m wide, and the bridge totals about 560m long, as it also spans highways and flood defences on both banks. Each individual span is about 75m.
The bridge is brilliant in its single-mindedness, comprising braced steel lattice truss girders unvarying in height, supported on masonry piers within the river. There's often something exquisitely beautiful about a bridge which appears to make no concession to beauty.
The most visually interesting feature of the bridge is surely one which was unintentional. The latticework on the trusses uses large diagonal elements which are formed out of steel angles. These inevitably create a pattern of light and shadow on the face of the girders. The arrangement has been alternated between spans, so that on a sunny day, each span of the bridge appears to alternative between a dark and light colour (third photo below).
Further information:
08 November 2014
French Bridges: 4. TGV Viaduct, Avignon
There are many impressive bridges in this part of France, but the twin TGV viaducts spanning the River Rhone are particularly spectacular.
They were built between 1996 and 1999, to a design conceived by Michel Virlogeux with Jean-François Blassel, and developed by RFR. Built as part of a TGV route extension, they were reportedly the first viaducts of their type to be built by the French railway body, SNCF.
The viaducts are each 1500m long, comprising a number of 100m main spans and 50m approach spans. They are post-tensioned concrete box girders, built in precast segments and erected using giant launching gantries. Both internal and external prestressing are incorporated.
A special white concrete was used in recognition of the visual sensitivity of the site, and taking into account distant views of the highly historic Palais des Papes in Avignon.
The most interesting feature of the bridge, visually, is the relationship between the concrete girders and the support piers. Tapering circular piers are topped with chiselled caps, widening out sufficiently to carry the bridge bearings. The lower face of the concrete girders dips down towards these points, while also widening out. This looks okay from some angles, but decidedly odd from others. In some views, it creates a pronounced and unwelcome visual kink.
As Britain develops plans for its second high-speed rail line, HS2, it will be interesting to see whether designers can match the high quality of structures such as the Avignon TGV viaduct. British designers are being challenged to develop repetitive, modular designs which can be largely pre-fabricated off site, and there will be a tension between the need to provide a consistent visual identity for the project against the need to consider the context of different sites through which it passes.
Further information:
They were built between 1996 and 1999, to a design conceived by Michel Virlogeux with Jean-François Blassel, and developed by RFR. Built as part of a TGV route extension, they were reportedly the first viaducts of their type to be built by the French railway body, SNCF.
The viaducts are each 1500m long, comprising a number of 100m main spans and 50m approach spans. They are post-tensioned concrete box girders, built in precast segments and erected using giant launching gantries. Both internal and external prestressing are incorporated.
A special white concrete was used in recognition of the visual sensitivity of the site, and taking into account distant views of the highly historic Palais des Papes in Avignon.
The most interesting feature of the bridge, visually, is the relationship between the concrete girders and the support piers. Tapering circular piers are topped with chiselled caps, widening out sufficiently to carry the bridge bearings. The lower face of the concrete girders dips down towards these points, while also widening out. This looks okay from some angles, but decidedly odd from others. In some views, it creates a pronounced and unwelcome visual kink.
As Britain develops plans for its second high-speed rail line, HS2, it will be interesting to see whether designers can match the high quality of structures such as the Avignon TGV viaduct. British designers are being challenged to develop repetitive, modular designs which can be largely pre-fabricated off site, and there will be a tension between the need to provide a consistent visual identity for the project against the need to consider the context of different sites through which it passes.
Further information:
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