Remote management and lighting control for urban tunnels
Often the most complex interventions are not those relating to new plants - in these cases the main difficulty is in the choice of cutting-edge technologies, while avoiding taking excessive risks - but rather those on plants in operation: to give some examples we think of the inconveniences, but also of the complexity of the interventions currently underway for the expansion of the GRA in Rome and the A4 between Milan and Bergamo. We work on structures designed decades ago, with significant constraints; the need to keep the work under renovation open to traffic, causing the least amount of inconvenience and at the same time ensuring the safety of construction sites: these are the causes that generate complexity.
This type of problem was faced and solved in 2005 in the case of the Corso d’Italia underpasses in Rome. It was a question of having to modernize the lighting systems of these important road junctions, built in 1963 by the company C.E.B.A.T. srl of Rome. After 40 years, the plants were by now inefficient and obsolete, while the traffic conditions had grown exponentially. However, it was unthinkable to carry out the work safely by closing off the important arteries.
Therefore the competition contract, won by C.E.B.A.T. in collaboration with an engineering company, provided for the assignment based on a score, in which half was derived from the evaluation of the solutions provided, both of a technical and logistical type. The winning project envisaged an intervention to be carried out in the period of less traffic, in 60 days, between 15 July and 15 September, developed in 4 phases. The original idea of subdivision into phases made it possible to never completely close the underpasses to traffic, but to always leave some accessible part, while the entire electrical and lighting system was redone in the area subject to closure.
The 3 underpasses of Corso d'Italia, which connect via Nomentana and the Policlinico to Piazzale Flaminio, required a careful and elaborate planning activity and an accurate and precise construction work, developed according to the most recent lighting regulations. of tunnels, energy saving and maintenance. In particular, the calculation criteria contained in the UNI11095 standard of December 2003 were adopted for the sizing of the lighting system, implemented by a subsequent Decree of the Ministry of Infrastructures.
The particularly severe conditions linked to the intense traffic, often congested, made it necessary to have a whole series of design conditions, developed paying particular attention to both the construction of the system, using materials capable of guaranteeing maximum durability and the lowest environmental impact during operation. normal and emergency, and to subsequent management, reducing maintenance and operating costs to a minimum.
The lighting devices used in the lighting system are made of stainless steel with low carbon content, are equipped with asymmetrical diffusing optics and equipped with long-lasting High Pressure Sodium type lamps.
The lighting system adopted in the underpasses is able to provide a user, both day and night, with a sense of security and comfort that is as similar as possible to what he can have outdoors. In particular, the system is able to recreate, in the entrance area, a level of lighting similar to the external one; in the transition zone, this level decreases according to a certain adaptation curve, obtained by varying both the distance between the lighting devices and the power of the lamps; in the internal area, finally, the level of lighting provided by the system allows the user to walk through the underpasses safely.
In the event of a sudden interruption of the electricity supply, due to a black-out, the lighting system is in any case able to ensure the protection of users by allowing a safe and orderly evacuation of the underpasses.
The use of fiberglass ducts to support the lighting fixtures and power supply cables guarantees high resistance to fire in emergency conditions and the complete absence of corrosive phenomena over time.
The use of an effective regulation and remote control system, provided by Revetec, allows correct functionality in any operating condition.
In the Corso d’Italia underpass, 249, 261, 82 and 225 floodlights were installed in the 4 phases respectively. In the underpasses of Piazzale Brasile and Via Po 180 and 254 lighting bodies.