The most striking of the modern bridges that were built over the old course of the Guadalquivir river in Seville in preparation for the ’92 Exposition is the Puente del Alamillo, built between 1987 and 1992 after a design by Santiago Calatrava.
After the Guadalquivir, the main river flowing through Seville, had caused several major floods, government decided to reroute the river to the west. The old course of the river, now a branch of the rerouted river, was renamed Meandro de San Jeronimo. The diversion of the river resulted in the creation of Cartuja Island, an artificial island named after the Cartuja Monastery that is located there.
In 1986, soon after king Juan Carlos I announced Seville would host the World Universal Exposition of 1992 to commemorate the Discovery of America, plans were drafted to improve Seville’s infrastructure. Several bridges across the Meandro de San Jeronimo were planned to connect the city with Cartuja Island, the proposed site for the exposition.
Of all the new bridges that were planned for Expo ’92, the design for the new Alamillo Bridge, planned just north of the expo site, was the most eye-catching. In 1988, Santiago Calatrava, a Valencian architect known for his sculpted designs, proposed the construction of two mirroring bridges. One bridge would cross the Guadalquivir and the other would span the Meandro de San Jeronimo near the city of Seville. A 1,5 km long viaduct was planned to connect the two modern bridges. This idea resulted in an asymmetrical design with bridge pylons inclined towards Cartuja Island, creating a symbolic gateway for the expo site on the island.
Unfortunately in 1989 escalating cost estimates led to the decision to scrap the design for a second bridge across the Guadalquivir. A more conventional, less costly bridge would be built over the river. The Alamillo Bridge across the Meandro de San Jeronimo however would be built following Calatrava’s daring design.
The Alamillo Bridge is a cable-stayed bridge with a 200 meter (656 ft) long span painted in Calatrava’s trade-mark bright white color. The most distinguishing aspect of the design is the 142 meter (466 ft) tall pylon, which is gracefully slanted at an angle of 68 degrees. The pylon is filled with concrete and acts as a counterbalance for the 35,5 meter (117ft) wide bridge deck, which is anchored by just thirteen pairs of cables. Thanks to this design there is no support needed at the back of the pylon, which results in a more elegant bridge.
The technical challenges met in constructing the radical design with an unsupported pylon were on par with those encountered during the construction of earlier landmark bridges such as the Golden Gate Bridge and the Brooklyn Bridge. The elegant design of the Alamillo bridge has been copied numerous times by other architects and many bridges around the world now feature a similar design.
The Alamillo Bridge, situated just to the north of Seville’s historic center, is best seen from the banks of the Meandro de San Jeronimo. The bridge is especially beautiful at night, when it is illuminated.