Beyond Science

A special format for this post, it is now never miss a chance to study and build a bridge !

The incredible Da Vinci Reciprocal Bridge, designed in 1495 and studied by civil engineers ever since, has been built in several places around the world. And now, after months of research, we've discovered even more about this remarkable structure!

In our latest article, published in the esteemed "Comptes-Rendus Mécanique" of the French Académie des Sciences, we have uncovered and demonstrated a recurrence formula that governs the interplay of forces between the beams that make up this remarkable bridge! We can't wait to hear what you think!

And here's a challenge: build your own bridge using pencils or knives. It's easy, fun and you'll be amazed at how well it can support loads without any assembly! And if you are ever curious and wonders around Blois one day, do not hesitate to see a real-life realization of this bridge in the gardens of the Clos Lucé Castle.

#bridge

#closlucé
#leonardodavinci
#reciprocalstructures
#publication

Built from 2007 to 2010 near Marina Bay in Singapore, this footbridge is not only nice to see but also interesting in terms of structural design. Indeed, the architects of COX Group Pte Ltd (Australia) and Architects 61 (Singapore) have designed the bridge not only to look like DNA but also to be a tubular beam inside which pedestrian can walk. It is composed of light steel curved beals and cables entangled in such a way to provide stiffness ! The curvature of the deck allows to better observe the beautiful design of the bridge but also of the Marina Bay Sands while crossing... especially since plateforms have been created that allow to step out of the bridge and enjoy the view.

Do not miss to walk on this bridge when you go to Singapore, hopefully the football pitch will be finished by then !

#bridge #civilengineer #singapore #footbridge

The Terenez Bridge (pronounce the z at the end) is one of the two possible terrestrial entries to the Crozon Peninsula in Britany. It replaces an old suspended bridge that was source of many accidents by Navy cadets that were late to go back to the Ecole Navale, based on the peninsula... Indeed, the roads on both sides of the Aulne river are almost parallel and a sharp almost 90 degree angle turn had to be placed at both ends of the bridge, would this bridge be straight, which was the case for the old suspended bridge. In fact, it is merely impossible, with a suspended bridge to build a curved bridge deck... However, notice that the Terenez bridge is curved ! This allows for the 180 turn to happen on a larger distance and thus to be safer ! The choice of the (world famous) engineer Michel Virlogeux and the architect Charles Lavigne to go for a cable-stayed bridge stems from that necessary curved deck... some say to ensure the safety of our navy cadets ! The curved deck is also the cause of the bridge's beautifully designed lambda pylons that have to be inclined in order to properly retain the weight of the road. Although Térénez is designed with an asymmetric form, observation of its cross-section shows that tensile loads in cables are transferred to the top of the towers in a rather symmetric manner. The top of each pylon is, in fact, located above the center of the deck’s cross-section, and cables are evenly distributed on both sides of the tower. The effect when you cross the bridge is majestic and you can confirm the assertion I just made (see second picture).

For those who like numbers, the bridge was inaugurated in  2011, it spans on 515m. It is the first ever curved cable-stayed bridge in the world. In 2013, it won the World Infrastructure Award, and in 2014, the prize for the most beautiful structure awarded by the International Federation of Concrete. It holds the world record for curved, unsupported load-bearing capacity.

Tower bridge is not only beautiful but it's a mix of a suspended bridge and a bascule bridge... It moves!

Built between 1886 and 1894 this bridge has been selected among 50 other projects some of which are presented in the very nice exposition held in the galleries at the top of the bridge. It is a creation of architect Horace Jones and engineer Sir John Wolfe-Barry. Both suspended parts span over 82m whereas the mobile parts span over 61m. They consist in two mobile basculing parts activated by an hydraulic machine. The top galleries allow pedestrian to cross the bridge even when the center part is lifted. They are suspended too! So nice...

I highly recommend the visit which is very interesting with a nice focus on workers and engineers!

No, your eyes are not fooling you, this bridge is actually not one bridge but two parallel twin bridges, built in 1958 for the first one and in 1988 for the second one... well they might not be true twins...

These bridges are cantilever bridges, a special kind of bridges where the mechanical concept is pretty much the same as a balcony : perfect for New Orleans right?

Anyway, when the first bridge was inaugurated it was said to be the longest cantilever bridge in the world. But, as always with bridges, one should be suspicious of the meaning of "longest" because it was the longest in terms of total length (920m) but only the third in terms of length of main suspended span (480m) -- what truly interests the engineer -- after the two world famous Forth Bridge (Scotland) and Quebec Bridge (Canada).

In 1988, the second twin bridge was open to circulation. Its creation solved the problem of the rapidly growing traffic need and allowed for the replacement of the old bridge's deck from asphalt-on-steel to concrete. It is way larger than its brother (28m against 16m) thus allowing for special large vehicules lanes.

These twin bridges are a delight to see while eating a beignet along the Mississippi River !

Built between February 1987 and February 1988, this is the third longest bridge in France (the first one being the Saint-Nazaire bridge and the second the Île d'Oléron bridge). It is composed of 6 viaducts in prestressed concrete and is arranged in a very elegant curve culminating 43m above sea level.

Of course designed by Michel Virlogeux this bridge is a must see!

With 2 bridges from the Eiffel family : the Dom Luis I bridge (engineer Théophile Seyrig, student of Gustave Eiffel) which has 2 decks and replace a suspended bridge where one pile is left and transformed into a coffee and the Maria Pía bridge (engineer Gustave Eiffel) with its beautiful hinges at the bottom of the arch. Note that both these bridges have a superior deck that is merged with the arch instead of above it which will become the signature of Théophile Seyrig!

The last bridge I am showing is the Arabia bridge, last one on the Douro river before the ocean! Thanks to a nice company Porto bridge climb you can climb in the arch of this bridge using maintenance stairs. Very fun experience for civil engineers and bridge lovers!

The cable-stayed bridge over the Zuari River in Panjim is still under construction.

A pedestrian bridge to walk between restaurants at high tide on the Ashvem page.

Atal Setu cable-stayed bridge to be completed in 2019!

Very recent specimens. Civil engineering still has a long way to go!

A built on bridge from the XIIIst century! Old school but still holding it well!

In South Jordan not much bridges so far but one on the highway to the Dead Sea and the "small bridge" in Wadi Rum.

One actually functionning bascule bridge in Cape Town. Wait a little bit to see it working it's fantastic !