There's no denying it. Pereira's striking new red and white "cable-stayed" bridge far outshines the city's other landmark --the infamous statue of independence war hero Simón Bolívar riding horseback nude through the city's central park.
This "Pearl of the Otún River," as the newspaper El Tiempo described it, promises not only to stand as a stunning visual landmark, but also to solve some very real transportation problems here in the heart of Colombia's coffee-growing region.
The four-lane structure, complete with sidewalks for pedestrians, links Pereira (pop. 350,000) with Dosquebrados (pop.100,000), and eliminates a major traffic bottleneck between the country's second and third largest cities, Medellín and Cali. Previously, vehicles had to cross the river via a two-lane roadway that descended to the floor of the river valley. The new bridge cuts up to 40 minutes off the driving time for the 35,000 vehicles that cross it daily.
Nearly two-thirds of the $45.4 million cost of the bridge and access roads was funded as part of a $1.7 billion program to upgrade the country's major highway and rail corridors. The program was financed with the help of a $300 million IDB loan approved in 1995.
The bridge's candycane color scheme was the backdrop for a festive inauguration last November that included bands playing salsas and cumbias, dance troupes and parade floats. Present were Colombian President Ernesto Samper, Minister of Transportation Jorge Enrique Rizo and Organization of American States Secretary General César Gaviria Trujillo.
"Who cannot be optimistic about Colombia's future now," said Gaviria, "after seeing the beauty of such a gigantic structure that not only unites two cities but also all Colombians."
More than 3,000 tons of steel rebars were used to reinforce the two huge concrete pylons upon which the bridge rests. In addition, the diamond-shaped pylons have small "footprints" where they meet the ground, another feature that provides earthquake resistance.
Earthquakes are a real concern in a city that was hit by a 7.5-Richter-scale earthquake in 1995. This was the main reason engineers chose the uncommon cable-stayed bridge design, whose flexibility enables it to withstand shocks.
Construction supervision by an Italian-Colombian engineering consortium was especially rigorous; every batch of concrete had to pass a 130-ton hydraulic pressure test.
"The flexibility of this steel and concrete structure should guarantee its ability to withstand earthquakes up to 8.0 on the Richter scale," says Vincenzo Gozzi, who was chief of construction supervision.
Figg Engineering of Florida, world experts in cable-stayed bridge design, created a step-by-step construction plan in which the two pylons would be built first and the steel and concrete road surface would be extended outward from them.
"It was a very delicate operation," says Figg bridge engineer Juan Goni, who worked on the project. "We actually built the bridge in the computer step by step by step, and computed the stresses for each step. Everything had to go just right to make sure that forces were kept within limits and that the two halves of the bridge surface would meet at the center."
The bridge was built by a German-Brazilian consortium, with assistance from firms from Portugal and France for geometry control and cabling. Construction took more than three years and employed 550 people at times. In an additional safety measure, computerized sensors from Italy and Switzerland costing $3 million were installed to monitor any changes in the bridge's physical condition caused by settling or earthquakes that would need to be corrected by adjusting cable tension. Colombia's National Highway Institute estimates that the bridge will pay back its $45.4 million cost in just nine years through savings in transportation expenses.
BRIDGE FACTS
Length: 703 meters
Height: 105 meters
Steel rebar (for earthquakes resistance): 3,000 tons
Vehicles/day: 35,000
Cost: $45.4 million
Repayment time (in transport savings): 9 years