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DEMOLITION OF THE ENEL CENTRAL CHIMNEY IN LA SPEZIA
The chimney of the ENEL “Eugenio Montale” power plant in La Spezia was built in 1967 without using any internal or external scaffolding and was the tallest in Europe at the time.
It is currently the tallest chimney in Italy undergoing demolition.
The chimney is 220 meters high and measures approximately 9 meters at the top and 16 meters at the base, while the walls are 92 cm thick at the base and 20 cm thick at the top. It consists of two concentric pipes, one made of refractory bricks and one made of reinforced concrete. The total weight of the refractory bricks is estimated at 2,500 tons, while the weight of the concrete is estimated at approximately 10,000 tons.
TECHNICAL DETAILS
Demolition methodology
Demolition is carried out using a special technique known as “top-down,” whereby the tower is demolished from the top down.
A self-elevating work platform on five columns (PLAC) connected to the structure by trusses houses two remote-controlled demolition robots that demolish the chimney, causing the debris to fall inside the cone itself. The PLAC is designed to adapt to changes in the diameter of the chimney during ascent and descent by means of a telescopic sliding system of the 5 working bridges.
TECHNICAL DETAILS
Management of waste material
In order to separate and sort the two types of waste generated by the activity, the demolition is divided into two main phases:
- Removal of the internal refractory brick chimney using a mini excavator equipped with infrared cameras, radio-controlled by an operator positioned at a distance. The mini excavator is placed on a work platform supported by four winches synchronized by a computerized management system.
- The demolition of the reinforced concrete shaft will be carried out using two remote-controlled electric demolition robots weighing 2 tons each, positioned on the PLAC edge and equipped with hydraulic demolition hammers that will crush the concrete, conveying the resulting material inside the chimney shaft itself.
Sustainability
Two water spraying and misting systems located respectively on the PLAC edge and at the base of the chimney will reduce dust from demolition activities, making the operation as eco-sustainable as possible, together with the use of electric vehicles.
With regard to concrete, with a view to sustainability, a waste treatment campaign is planned on site in order to make it suitable for recovery and reuse within the plant for filling without having to resort to the extraction and purchase of new virgin quarry material.
