|CLOSE Venues in 2004 Summar Olympics may finish just barely before games begin in August. (Photo courtesy of Nikos Daniilidis)|
Preparations for the summer Olympic Games in Greece, set to begin Aug. 13, are so late that the prime minister took personal responsibility for their timely completion just after winning this months elections. Last-minute construction is most critical at the crowning main stadium in Athens. Even with nonstop work, its 304-meter-span arching roof will be ready only weeks before the globally televised opening ceremony is set to take place under its cover.
After meeting Prime Minister Costas Karamanlis, Jacques Rogge, president of the International Olympic Committee, said recently "there is still time for the preparation if all energies are mobilized." At the stadium, nobody doubts the urgency. "Can you imagine an Olympic Games with the steel structure unfinished on top of the stadium?" says Leonidas Kikiras, project coordinator for the stadium complexs architect, Santiago Calatrava. "Its a nightmare."
Before workers can install more than 2 hectares of polycarbonate roofing and hook up equipment, next month they must slide the two halves of the 77-m-tall, 18,000-tonne structure over stadium seating. "Other companies have slid more weight, but this thing is so high. Its still a risk factor," says Petros Stavrou, construction manager with main roof contractor Aktor S.A., Athens.
With its bridge-size arches, the roof is "a very symbolic issue," says Costas Cartalis, the culture ministrys general secretary for the Olympic Games. He labels as "extremely unfair" the pall that has spread over other preparations by the stadiums notorious progress. "Everything will be completed [on time]," Cartalis says. "The focus now is on all elements that make the games really successful, or really a mess."
Around Athens, many Olympic venues are visibly well-advanced. All 2,300 apartments at the Olympic Village are to be handed over to organizers in May. A contractor is installing 9,000 seats at the wrestling center, having begun construction 17 months ago. About 30 out of a total of 40 venues are either complete or more than 90% built, say Cartalis staffers. The main stadium complex and a soccer field in Piraeus, both less than 80% ready, are the least advanced. Transportation links are mostly in place, but work continues on the 27-kilometer tramway. The 32-km suburban railroad along the airport expressway wont likely open before July.
But even Cartalis agrees that valuable time was lost after Athens won the right to host the Games in late 1997. The initial ill-fated policy of extensively privatizing venue developments took up much of the first two years. "A number of projects were tempting from a finance and exploitation point of view...but it didnt work out," he says.
Political indifference and legal and bureaucratic obstacles were rampant then, says George Leventis, the first director general of construction for the Games Athens Organizing Committee. "By mid-1999, it became evident to us that it was not working," says Leventis, a principal at Langan Engineering and Environmental Services Inc., Elmwood Park, N.J.
In 2000, "the government took over, and the master plan was updated with a clear view to use the games as a catalyst for urban development," says Cartalis. Local objections then hindered planning, adds Sotiris Douros, a former mayor of the municipality containing the Olympic Village. Cartalis says he spent most of 2002 defending 49 legal challenges. He won 48.
|(Photo by Peter Reina for ENR)|
With the slow buildup, construction of many projects began only in 2002, although work started earlier at the Village. Because of hurried preparation, design proceeded after construction started. "Designs existed, but they needed clarification," says Douros, now a government technical adviser. "They were not [fully] available during the tender." Resulting cost hikes have been widespread but within the budget, claims Cartalis.
With a current $4.5-billion budget, 95% for Athens, the Olympic facilities represent a vast investment for a nation with fewer than 11 million people. The public commitment now is many times higher than at the start, when the entire budget, including nonconstruction elements, was about $2 billion.
Design changes at the 37,000-sq-m shooting center outside Athens added 10% to the $62-million cost, says Costas Arvanitakis, main contractor Alte S.A.s project manager. The 18-month project should have ended last year, but "we had a few extra jobs," he says. But the cost hike "is not much for such a project," Arvanitakis adds.
At the stadium complex, an extra $30 million has been allotted for the main roof, but further claims are pending. The main contractor, Aktor, and its Italian steelwork subcontractor are in arbitration over costs related to the projects rocky past. The Calatrava-designed roof is the Games boldest element. By adopting his daring design, the government made "an historic decision," says Dimitris Kallit-santsis, Aktor managing director.
|RISKY Calatrava-designed stadium roof was a bold move for Greece (top) but it has been tough for contractors. (Graphic above courtesy of Santiago-Calatrava S.A., photo below by Peter Reina for ENR)|
The main roof is in halves, each supported by two arches, one above the other. With diameters of 3.2 m and 3.6 m, respectively, the upper and lower tubes merge at a common "shoe" at each end. Weighing 550 tonnes each, the hollow steelwork shoes are 6.5 m high, 11 m long, ultimately supported by piled slabs.
Cables from upper arches suspend roof girders and help support the lower tube. The tubes main function is to counter, with up to 15,000 tonnes of torsion each, out-of-balance loads from the roof that curves over the long banks of seats on either side of the stadium.
The roof halves, which connect only at each end, consist of tapering, inclined steel truss ribs that weigh 15 tonnes, on average. Bolted at right angles to the lower tube, their lengths increase from mid-span outwards. Cantilevering lengths toward the field range from 5 m to 55 m, while the corresponding opposite projections are 32 m to 11 m.
Kallitsantsis own motivation in leading Aktor to the contract was partly to gain international kudos for succeeding with the remarkable roof, he says. The countrys largest construction firm tried unsuccessfully to find an international contractor to share the risk. Even knowing that failure would give Aktor "a bad name in Europe," Kallitsantsis urged its management to bid alone.
From the start, the roof project faltered when a disappointed consortium challenged its exclusion from the bidding process, says Cartalis. With the ensuing legal battle, "a project that had a comfortable timetable suddenly lost eight months," he says. Firms that did prequalify in April 2002 submitted bids that summer, but all broke the budget, says Stavrou.
|FINISH? Velodrome roof will be slid into place any day now at summer games construction site. (Photo by Peter Reina for ENR)|
After negotiations, Aktor signed a contract the following November. Its work at the main sports complex includes covering seating areas of the 22-year-old main stadium and installing a similar, 3,500-tonne cover on the existing oval velodrome nearby. Landscaping and other work raised its contract total to nearly $250 million, not counting disputed extras.
In the first months, the team developed outline designs used for bidding. "The contract was awarded [even] before wind tunnel tests," says Stavrou. A major design change enlarged the roofs upper and lower tubes by 0.3 m and 0.4 m, respectively, in exchange for better buckling resistance, says Calatravas Kikiras. "That had important impacts on the weight," he adds.
While designs continued, the roofs fate remained uncertain. Having to move such large arches, "the magnitude created fears," says Kikiras. "Only after last July [were] all the participants convinced the structure was safe, feasible and could be built on time." Aktors Stavrou adds that the firms familiarity with other contractors on the job allowed it to promise owners that the team could meet the deadline.
Aktors Italian subcontractor, Costruzioni Cimolai Armando S.p.A., Pordenone, had an initial $75-million contract to fabricate and erect the main roof, but the total will be significantly higher, according to Salvatore de Luna, its commercial director. Fabricating the steel at four of its five Italian plants, Cimolai regained some lost time by doubling tube erection supports to raise both sets almost simultaneously.
Cimolai began by raising, with the use of cranes, parts of each top arch on five temporary towers on either side of the stadium. Other stadium work prevented erection at the final positions. With tower-top strand jacks, the contractor then raised preassembled intermediate sections. Each lower arch was similarly built, and upper and lower tubes welded together at their ends.
After main cables between the top and bottom tubes of the west roof were stressed, the weight of the arches was recently transferred to its supporting shoe, and the towers removed. Workers are now bolting roof ribs to the lower tube, supporting them on a second set of towers. Cables between the top arch and ribs are being simultaneously added and partially stressed. Final stressing will start in May when polycarbonate roofing is applied. Work on the east roof follows closely.
With current progress, Cimolai is set to slide both roof assemblies an average of 65 m over the stadium bowl. Powered by horizontal jacks, the shoes will slide on stainless steel-lined tracks until the arches are over the innermost seats, about 140 m apart. Set for April 14 and 24, the slides should take about 10 to 12 hours each, but Aktor has allotted four days in case of snags.
Until now, Cimolais workers have concentrated on welding and bolting inside the arch tubes. Roof erection has seemed quiet, raising press complaints of inactivity. But a furious de Luna insists that Cimolai is "working day and night with 150 people and 10 cranes." As time passes, project principals admit to sleepless nights of anxiety. But racing to an adrenaline-fueled conclusion, says Aktors Kallitsantsis, "is the Greek way."