One of the main road projects to the city of Rio de Janeiro, Novo Joá was inaugurated this Saturday, 05/28. After 23 months of interventions, a new path is opened between the sea and the slope of São Conrado.
With investment of R$ 457.9 million, Novo Joá project was conceived by Fundação Geo-Rio, and it will increase by around 35% the traffic capacity between the South and West zones through two new traffic lanes. The project comprises the construction of two new tunnels in parallel with the existing ones, one viaduct, one overpass, one bridge, the widening of important routes and one bike lane with 3,100 meters, which will connect São Conrado to Barra da Tijuca.
Built by Construtora Norberto Odebrecht, the project used eight different constructive methodologies, with the challenge of simultaneous realization of all the fronts of services and reduction of the impact on the routine of the neighboring residents and traffic.
The construction included 260 detonations to open two new tunnels with the support from 1,800 workers to remove 92 thousand m³ of excavated material as well as the installation of 505 slabs and 120 precast concrete beams, and many other services for construction of the project.
The main constructive methodologies used in Novo Joá included:
Successive Swinging: to build the new bridge of Joatinga, this method was used to overcome gaps in areas where it is difficult to assemble shores. During the structure assembly phase, the parts advance in swings, one by one, until the total execution, with the support of metallic trellis.
Mixed Bridge: the structure of the new Bridge of Joatinga is formed by metallic structures with concrete slabs and pillars.
Underground excavation: to open the two tunnels included in the expansion of Elevado do Joá, it was used 78 tons of explosives. In order to minimize the impact of this phase, Construtora Norberto Odebrecht adopted a mechanism that reduces noises and vibrations during excavations in rocks, called Hand Time Det (HTD). This method replaces the traditional detonation string, which reduces the effects of air movement and causes less sensation of vibration and noises. Each hole loaded with explosive is detonated in fraction of seconds. The detonations occurred from January to July, twice per day, at 2 p.m. and at 9.45 p.m.
Superstructure of New Overpass: Constructive method divided into three stages, as beams, precast concrete slabs and consolidation. During this important phase it was used beam launching trellis, equipment that operates over special supports, and permits to move these concrete structures of 37 tons each, from the yard of precast to their respective supports. The trellis demands less space when compared to traditional cranes and provides optimization of time for construction of the overpass, not using the existing path, thus causing no interference in the traffic of vehicles.
Also, at the final phase of construction, three tests were made in Novo Joá. In the overpass and in Joatinga Bridge, tests with static and dynamic cargos evaluated the capacity of these structures. In the first test, eight trucks weighing 17.5 tons were used, and in the second test it was used a wagon weighing 45 tons. In the bike lane, a test of horizontal and vertical impact and effort on the handrail of the lane is being conducted.
Curiosities about Novo Joá