|TOUGH TERRAIN Concrete viaducts span mountain valleys but slope stabilization and reinforcement has been difficult. (Photo by John J. Kosowatz for ENR)|
For centuries, Croatia's geographic location as a flash point between East and West has made the small Balkan country a battlefield. Culturally tied to the West and often dominated by the East, independent Croatia is looking in both directions to tap its undeveloped coastline and a lucrative tourist industry that could fuel its struggling economy. The first step is to speed access to the coast through an ambitious multibillion-dollar motorway that will replace a snake's tail of narrow, two-lane roads winding through the tough Klek mountains.
A joint venture of U.S. contracting giant Bechtel Group Inc., San Francisco, and Turkish heavyweight Enka Construction & Industry Co. Inc., Istanbul, is now pushing the road's largest segment, a $990-million, 189-kilometer toll road, through unstable mountainous terrain littered in places with unexploded ordnance and abandoned mines left over from Croatia's latest conflict, its 1991-95 war to separate from Yugoslavia. When completed, the road will link Zagreb, the capital, with the coastal city of Split, and eventually Dubrovnik farther down the Dalmatian coast.
Primarily a gigantic earthmoving job, Bechtel/Enka has spent nearly $200 million alone on heavy equipment to move some 98.3 million cu meters of earth and fill and clear and grub 946 acres of land. Thirty-four bridges, all precast concrete, will take vehicles around mountains and over spectacular, undeveloped valleys. The project is loaded with geotechnical and logistical challenges, compounded by cultural differences and wariness between Turks and Croatians that goes back centuries. Forging some 2,400 Croatians, Turks and Americans into an efficient roadbuilding work force has been as much a challenge as cutting the road, says Jack Hume, Bechtel project director. "This job has got just about everything," says Hume, a 25-year veteran with the firm who took over the project in 2000.
Despite its European location, the sprawling jobsite traverses a remote and largely undeveloped area, dotted with small villages connected by aging, narrow roads. It begins at Bosiljevo, south of Zagreb, slicing further south to Sveti Rok, and is a key section in a trans-European road network connecting Croatia to Western Europe. Conceived during the Dayton Accords, it is funded through the U.S. Export-Import Bank and administered by the Croatian Roads Authority, which also is responsible for obtaining rights-of-way. Design is by three Croatian firms. Click here to view map
Bechtel began work in 1998, shortly after signing a contract with the public works ministry, and is on track to finish in 2004. The first northern 44 km are nearing completion. As the job moves south, the first work camp, at Ogulin, is clos-ing down and a second, at Gospic, already houses 500 workers. Another 200 are based at a former munitions factory along the route. Hume says the work force will peak at 3,000 before the construction season ends in November.
All construction sites are dangerous, but the project's route through the former front lines of the Croatia-Yugoslav war and an abandoned munitions factory make the motorway especially risky. Hume stepped up an aggressive safety and training program after he found himself in the middle of an abandoned minefield during an early site visit. "It scared the hell out of me," he says.
|HAUL New road will remove bottlenecks in Croatia (Photo by John J. Kosowatz for ENR)|
Workers are briefed on the dangers and are forbidden to walk outside of the alignment's boundaries, marked with rope. Anyone doing so risks being fired. Although the government removed 99.6% of all known mines before the job began, Bechtel started its own risk-reduction program and hired former Croatian army munitions experts to seek out the remainder.
Officials mainly are concerned with antipersonnel mines that explode and scatter metal shot. As the alignment moved south, teams working with explosive-sniffing dogs laid out a grid, advancing about 200 m per day, says Elvir Had¯zihalilovic, the team's leader. The government was called in to remove and dispose of any explosives that are found.
A Kevlar-protected Caterpillar D-9 dozer then scrapes off the top 35 centimeters of soil, about the depth at which mines were placed. The D-9's big blade and the Kevlar panels along the side protect the operator. Munitions experts say the D-9 by itself provides the most efficient removal effort. When it finishes, heavy earthmoving equipment follows, the bulk of it Caterpillar. The dogs and D-9 recently finished clearing the entire alignment and crews are working at more than 80 locations along the route.
The job has suffered one construction-related death, but a strict safety and training program is paying off. Hume reports the job now is at 160 days and 3 million man-hours without a lost-time accident. To accomplish that, project officials started with the basics. "Teaching safety is challenging," says one official. "The Croats have no history of safety" and Muslims place their faith in Allah. "We had to build safety into two cultures where it was nonexistent," he says.
Because there are no safety requirements under Croatian law, about 65 superintendents were brought in to teach workers Bechtel's safety program, turning a bus into a mobile training facility. All workers must wear hard hats and safety glasses and those working on structures must be tied off with a full body harness. Rigging plans for lifts of over 10 tons are calculated beforehand and hand signals have been standardized. Workers also have been taught key terms and phrases in three languages, Croatian, Turkish and English.
Since signing the contract in 1998, the contractor has had to adjust quickly to major changes in alignment. Originally planned to run from Croatia through Bosnia, the alignment was rerouted west through Croatia when the two governments could not agree on a border crossing. Bechtel, which submitted its original proposal without a clear design, now is working on a completely different alignment.
A 40-km segment between Zagreb and Sisak was to start next year but is held up over environmental concerns for underground water supplies. A 13-km segment linking Bregana at the Slovenian border to Jankomir, outside of Zagreb, was finished in 2000. The entire route will have conduits for fiber optics. Drainage includes concrete lagoons to prevent spills or contaminated water from entering pristine streams.
Bechtel/Enka's route is divided into six subsections, the first two nearly completed. Portals at the 5,800-m-long Mala Kapela tunnel are now being prepared by Italian contractor Coopconstruttori, Argenta, under a separate contract (see map.) Bechtel/Enka's section ends at Sveti Rok. The last portion to Split was awarded to a consortium of local firms, which started work last spring.
Hume has crews working 12-hour shifts, six days a week, to take advantage of good weather. Crews already are pushing south from the Mala Kapela portal toward Licko Lesce, 12 months ahead of plan. Further south, between Licko Lesce and Sveti Rok, workers are moving 40,000 cu m of earth per day.
The region's peculiar geology of soft limestone, called karst, has been especially troublesome. Numerous fissures and 47 caverns have opened during excavation and even during scraping and compaction. Some were deep enough for spelunking staff geologists to investigate. Each requires a customized fix but often are covered by spreading the motorway's foundations.
DANGER Alignment abuts war-torn villages not cleared of explosives . |
Dogs sniff for mines followed by armored dozer. (Photo by John J. Kosowatz for ENR)
Slope stabilization has proven to be difficult, especially within the deeper cuts. "We've got every type and method you can use," says Mike Peachey, the project's engineering director. Besides shotcrete, rockbolts, stone and wire mesh, a composite product of mesh and matting on which grass can be grown is being used. But the fixes are costly. The venture already has racked up $1.3 million in added costs for reinforcement and stabilization, says Chuck Farber, the project's prime contract manager.
Most bridges are founded on rock with spread footings but a few utilize caissons. Most use standard 40-m-long precast girders. Crews were launching two beams in 9 hours on upper segments.
Project management is divided between Bechtel and EnkaHume's Turkish counterpart is Özger Inalwith local engineers integrated into the structure. As the biggest game in town, Croatian subcontractors have flocked to the motorway. About 70% of the work was sublet and procurement is done in-country, when possible. But subs are playing by the joint venture's rules. In the end, the motorway's greatest legacy may be training the local work force in modern and ethical practices.