O Empreiteiro magazine visited the road logistic axles in Rio de Janeiro under concession. There are many ongoing constructions works in the Dutra Highway, BR-040, BR-101 Norte and BR-393. Impacting projects have also been planned. Total investments sum up over R$6 billion.
Below, a summary of what has been done to improve road’s traffic capacity in that state.
New slope on Rio-Petrópolis with a 4.6 km tunnel will be ready before the Olympic Games
The city on the hills is the biggest tourism attraction near Rio de Janeiro in addition to the coast; the road also connects that capital city with Minas Gerais state
Augusto Diniz – Petrópolis (RJ)
In the World Cup it was usual to see Brazilian and foreign tourists walking around Petrópolis. Less than 70 km far from Rio de Janeiro, the city has several historical buildings and monuments from the time of the Empire, in addition to an agreeable weather, good restaurants, breweries, cheap and intense clothing stores, in addition to lush vegetation at the National Park Serra dos Órgãos.
Certainly, the city will host again thousands of visitors in the Olympic Games as a tourism destination beyond the beaches.
On the other hand, Rio-Petrópolis road is also the main route for heavy trucks traveling to Minas Gerais, the third richest state in the country, just behind Rio de Janeiro and São Paulo. However, the current stretch leading up to the hills is old-fashioned and full or curves; it was inaugurated over 100 years ago and it is now saturated, the road has no shoulders and it is a nightmare when a car or truck breaks down there, or when convoys of heavy trucks decide to take that road, or yet on holidays and weekends.
It is within this context of offering more fluid traffic with lower environmental impact that the so-called “Way up to the hills” being built at R$1 billion approximately. The jobsites today have 1,600 workers all along the stretch, with over 250 machines and trucks in operation o.
The project had already been under discussion when Concer took over the operation of the BR-040 in 1996, between Rio de Janeiro and Juiz de Fora (MG), passing the municipality of Petrópolis at the top of the hills, totaling 180.4 km. At the end last year, the rest of the segment of the road, from Juiz de Fora to Brasilia, was adjudicated to Invepar.
The new road going up to the hills is 20.7 km long and it started to be built in April 2013. It starts in the district of Xerém, Duque de Caxias, in the outskirts of Rio de Janeiro, and moves ahead as far as Petrópolis. A 4.6 km long tunnel is the main phase of the construction work. 28 bridges and viaducts are being built to widen the structures. After the work is ready, the former road going up to the hills should be transformed into a park-road, once it cuts areas of environmental protection.
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The construction has been divided into five lots: lot 1, from km 103 to 97, where a new lane is being built and a new area for the toll booths; lot 2, from km 97 to 87.5, where a new lane is being built; lot 3, from km 87.5 to 82.5, where the tunnel is being built; lot 4, where the tunnel will be connected to the entrance of Petrópolis at km 82; and lot 5, where there is a connection with Petrópolis’ districts, Bingen and Quitandinha, through the old road.
According to the operator, lot 1 suffers much interference because it is located in a densely populated area. At that stretch it has been necessary to relocated 1,700 m of water ducts of Petrobras which supplies Refinery Duque de Caxias. Also at that lot, the toll-booth area is being moved so that people who come and go from/to Xerém from/to the city of Duque de Caxias do not have to pay the toll – the situation used to create conflicts with the community, even with the special access agreed with the operator.
At lot 2 it is where most of the widening work of slopes is taking place. At lot 5, the connection of the districts Bingen and Quitandinha was an old claim of Petrópolis, which now will be done based on a stretch of the road to be deactivated due to the construction of the tunnel.
Tunnel
The most complex phase of the “New Way up to the Hills” is the tunnel, whose construction started last January. The choice was mainly made due to low environmental impact. The structure will have two lanes going up plus shoulders with a 6% inclination. The section is 122.3 m2 long with a confined safety gallery. The excavation method is the NATM.
For the initial works for the entrance and the exit of the tunnel, excavations were done in a mixed section of rock and dirt, without detonation.
At the entrance of the tunnel the side drift method was used by recommendation of the project companies (Intertechne and PCE). Excavation is done with a gallery at each side (the bigger one for vehicles to enter the tunnel). Up to 78 m have been excavated with this process. Only after the whole tunnel has been excavated will the inner part between the galleries be removed from inside out.
At the exit, work is making headway where a jumbo drilling machine makes the holes at the fire plane, then there is the detonation, a shovel clears the area and the dirt is removed, a machine maps and removes fractured rocks, 4 m beams are placed, concrete is poured – the concrete contains synthetic polypropylene fibers for better safety against heat, once the tunnel is rather long.
Excavation has been done in gneiss rocks, which are very abrasive and usually seriously wear off the machines.
Today, the exit moves ahead 4 m a day, but the goal is 6 m/day soon – there is an explosion every day, but the goal is three detonations every two days, reaching 30 m of weekly excavation. At the entrance, excavations advance lowlier. At the end of July detonations started; until then the excavation process was done with a breaker.
A window with a 333 m long access is being built to create two more excavation fronts in the tunnel – one towards the entrance and the other towards the exit. Expectations are that next November those two excavation fronts will be operating.
That window is currently undergoing a treatment of the hillside before excavation starts. The window’s entrance is located on the border of the BR-040' lane leading down the hills. The site has suffered some dirt sliding in the past and one can see old contention walls made on the rocks there.
The consortium has added 350 beams to secure the hillside. Also 1,500 m2 of highly-resistant screen have been placed. In the window there is intense monitoring of settlings. Detonations have started this month (August). The window has a section between 7m and 8m. It will be used as access to service in the tunnel.
A special exhaustion system will be implemented in the tunnel when it is complete with about 40 fans, and there will be gas gauges all along the tunnel. In addition to having vehicles riding long stretches confined, the natural dispersion of gas emissions they trigger will take place in the same direction vehicles are moving, i.e., upwards, which will demand an efficient and controlled exhaustion system.
Fonte: Revista O Empreiteiro
