1. What it has principally in its favor is a wonderful
landscape setting, to which the bridge proves
responsive in a number of ways. For one thing, it
curves in plan, gently resolving the divergent
geometries of the north and south banks. In order
to keep it above flood level, it extends far beyond
the river’s edge on both sides. Massive
embankments serve to anchor — both structurally
and visually — either end in the ground.

2. The structure is not, however, a single span. A third point of support is provided by a small island two thirds of the way along
the bridge’s length. The island’s eccentric location invests the structure with an asymmetry that Hadid — if not her engineer
— has clearly relished.

3. Zaragoza Expo 2008 is dedicated to water and sustainable development.
The basic module from which the whole structure has been derived is a triangular steel frame. It is repeated at 3.6m
intervals along the bridge’s length, and adjusted in height and width with each iteration. What emerges through this
procedure is an arched truss which is then lined out to become a spatial enclosure.

4. The pods are stacked according to precise criteria – aimed at
reducing the section of the bridge as much as possible where the
span is longer (approximately 185m from the island in the middle
of the river to the right bank), and enlarging it where the span is
shorter (85m from the island to the Expo riverbank). One long
pod spans from the right riverbank to the island, where the other
three are grafted into it, spanning from island to left bank.

5. ZARAGOZA BRIDGE PAVILION [ZARAGOZA, SPAIN] Underneath the floor plate, a resulting triangular pocket
The Zaragoza Bridge Pavilion is organized around 4 main objects, or space can be used to run utilities. Floors inside each
“pods” that perform both as structural elements and as spatial pod are located at the Expo principal levels: +201.5m
enclosures. The Bridge Pavilion design stems from the detailed (the soffit of the bridge is at +200m, flood protection
examination and research into the potential of a diamond shaped minimum level of the Ebro River at the location of the
section – which offers both structural and programming properties. As Bridge Pavilion) +203m, +206m and +207.5m for the
in the case of space-frame structures, a diamond section represents a upper level.
rational way if distributing forces along a surface.

6. The diamond section has also been extruded along a slightly By intersecting the trusses/pods, they brace
curved path. The extrusion of this rhombus section along each other and loads are distributed across
different paths has generated the four separate ‘pods’ of the the four trusses instead of a singular main
Bridge Pavilion. The stacking and interlocking of these truss
element, resulting in a reduction in size of
elements (the ‘pods’), satisfies two specific criteria: optimizing load-bearing members.
the structural system, and allowing for a natural differentiation of
the interiors, where each pod corresponds to a specific exhibition
space.

7. Spatial concern is one of the main drivers of this project. Each zone
within the building has its own spatial identity; their nature varies
from complete interior spaces focused on the exhibition, to open
spaces with strong visual connections to the Ebro river and the
Expo.
Natural surfaces have been investigated when designing the
Pavilion’s exterior surfaces. Shark scales are fascinating paradigms
both for their visual appearance and for their performance. Their
pattern can easily wrap around complex curvatures with a simple
system of rectilinear ridges. For the Bridge Pavilion, this proves to
be functional, visually appealing and economically convenient.
The building’s envelope plays an essential role in defining its
relation to the surrounding environment and atmospheric
variations. The project has been designed to allow its interior to be
thoroughly enlivened by the effect of atmospheric agents, such as
the Tramontana wind blowing along the Ebro and, the strength of
Zaragoza’s sunshine.
During the Expo, a single weathering layer will enclose the building
to protect it from rain. This Shark scale skin will be generated by a
complex pattern of simple overlapping
shingles. Some shingles can rotate around a pivot, allowing for
This interlocking of the pods has given the design many exciting
temporary opening or closing of part of the façade. The pattern of
possibilities. Interiors become complex spaces, where visitors move
shingles overlapping each other gives the Bridge Pavilion the
from pod to pod though small in-between spaces that act as filters – or
widest variety of natural light via several degrees of aperture sizes:
buffer zones. These zones diffuse the sound and visual experience
from rays piercing through tiny apertures – to wide, full size
from one exhibition space to the next, allowing for a clearer
openings. Large apertures are located on the lower level, in
understanding of the installation content within each pod. The identity
correspondence with either end of the bridge, allowing for the
of each pod remains thoroughly readable inside the pavilion, almost
greatest degree of visual contact with the river and the Expo.
performing as a three-dimensional orientation device.

8. •The bridge comprises four such trusses. Two are laid end to end, forming the public route. The other two
are rammed in from either side and serve as exhibition halls. The plan that results is trident-like, the handle
bearing on the south bank, the forks pointing north.
•Early on in the project’s development, the design team considered the possibility of an engineering solution
based on a series of shell structures. This was ultimately rejected because the architect felt that such a
monolithic structure would give the project the presence of a piece of heavy engineering. What Hadid
wanted was a finer, more building-like scale. The bridge’s external image is very largely, therefore, a matter
of cladding.
•The lower level has been faced in premoulded steel panels, giving it a sinuous, aerofoil profile. Above, we
are presented with a skin of mosaic-like glass-reinforced concrete panels. Comprising a series of interlocking
triangles, this treatment is built up of ten different cutting patterns, each of which is assigned a distinct tone,
graduating from black to white.