Frame and Form

Ponte della Costituzione is the 4th bridge over Venice Grand Canal. It was designed, involved in controversy, by Santiago Calatrava. Although it is difficult to ignore it, at Frame and Form we will try to put aside any criticism, especially the media-political one, and we will try to analyse the just the footbridge design.

Calatrava's works, and especially bridges, usually have a high visual impact. However, This gateway is different from previous works. It is designed to stress without imposing, as it is located in an urban environment of high architectural and historical value. By place (Grand Canal)and opportunity (is the first bridge built in Venice for decades)this is a historic bridge that must endure as an example of architecture of his time;Probably that is the reason Calatrava's election as a designer for this project, because like it or not want, This has changed the way architects design bridges.

Massarotto Photo Frame

Calatrava try to translate their vision with a simple line, a curve that is both road and structure. Apparently nothing new because in Venice predominate arch bridges which trasdós as the street itself. However, The new structure aims to be as slender and thin as possible, emphasizing the linear nature of the arc, and trying to merge form and function in a single curve.

Massarotto Photo Frame

The rails are made of glass panels and copper railings. No amounts to alter the profile of the runway. Among the fascia board at the foot of the rail line has been placed artificial lighting on the floor, returning to mark the silhouette of the bridge at night. The lighting of the rail is completed with LEDs located below the handrail. The fascia has been done natural stone from Istria which is characteristic of Venetian architecture.

Photos from Gabriel Bruna para Venice City

As the floor of the walkway is used the same materials; tempered glass on the sides and Istrian stone for the central area of the road. The glass frontage roads are lit from beneath, creating a luminous trail.

Massarotto Photo Frame

The stirrups are really beautiful and plastic parts, that integrate naturally with the access channel and docks. Its structure is of reinforced concrete but is hidden by the lining in Istrian stone. Such coatings are continuing right along the fascia of the bridge has been built with the same material.

Photos from Venice City

La estructura consta of 3 arches 81 m span: A major arc 180 m radius whose guideline is parallel to the ground pedestrian; and, on each side of main arch and slightly below it, have been built much lighter two arches, whose curve follows a distinct path, as it separates from the main arch in the key (center of the bridge) and joins him in startups (in the stirrups).

Photos from Venice City

The section of the central arch is a triangle formed by a horizontal plate in its upper, and two slanted plates that are welded to a circular tube in the lower corner. All of its elements, plates and profiles, are steel, but really this section is mixed, as above the upper horizontal plate has built a concrete slab attached to the plate. The concrete slab has been coated forming steps with Istrian stone tiles forming the pavement of the road.

Photo of Daniel Clements

On each side of the central section of the stone path are glass surfaces that are held flat on ribs or beams in the form of metal overhangs leave the section of the main arch.

Two metal sections form each side arches; on the inside a tubular circular section and the outer side another soldier to the previous profile but rectangular. Probably the combination of these hollow is to prevent buckling in a horizontal plane of the arches. If the lateral arches had joined each other through a type of triangulation in a more conventional design would not have required the welding of the two profiles. They must have primacy formal reasons.

Massarotto Photo Frame

The main arch and the two side arches are joined by inclined uprights, we do not know if that inclination is a radial pattern about the center of one of the arches. These amounts are attached to the ribs forming a single piece in X.

Photos from Alexander Zanchini para Venice City

The set of 3 arcs form a structure of great plasticity and dynamism but inefficient. On the one hand, the main arch is much stiffer than the side arches as it has more singing and curvature. Therefore, seems (is difficult to quantify)lateral arches that are lightly loaded, that is, little to help central arch, and in any case they do in the key area, which is where there is more vertical separation between arcs. This provision is contrary to the design of the supports of the arches that are embedded in the stirrups (= built the first section of the arch can not rotate with respect to the support surface).

Photos from Alexander Zanchini para Venice City

On the other hand, the 3 arches are low in height (7 a 10 m on channel), that is, or low arches are stilted. To work properly need to temper and their foundations to resist large horizontal forces. We all know that Venice is built on a lagoon and the fund is made up of soft soil in which it is difficult to build a foundation to resist horizontal forces.

We do not know the final solution to this problem, but it should be noted that their existence does not necessarily invalidate the original design of Calatrava. In fact, as mentioned above, all the bridges of Venice are arches that suffer a greater or lesser extent the same problem.

Massarotto Photo Frame

Meta-information:

Web dedicated to the bridge by the City of Venice (in italiano). Other things you can find a Gallery extensive and special section on the transport and assembly Bridge, which includes a dossier with technical data transport.

This gateway has received heavy criticism for not being suitable for the disabled. The council website devotes a paragraph to ovovia, which is a curious car transport for those with access difficulties.

Ponte della Costituzione in Wikipedia as an Italian and Spanish version. Official website Santiago Calatrava. Santiago Calatrava in Wikipedia. Unofficial website dedicated to Santiago Calatrava (English). Calatrava Statements about the design of the catwalk.

Beans Group is the engineering firm that made the transport and lifting of the bridge. This page includes a assembly video Bridge (English and Italian).

Video montage of the central section Bridge on youtube, and videos de virtual Beans which explains the construction of the bridge. (Although these videos can be located through the pages dedicated to the bridge we have preferred to put the links.)