• One of the tallest dams in the world. • height: 262 m • 27 m thick at the base • 3,4 m thick at the top Where is the dike sitting? Why was the dam here? • In North of Italy, Dolomites • Because they wanted to build a ponds. -> To have enough water • 100 km from Venice when there aren’t a lot of rain. • On the Vajont River • The Vajont River gouged the volley. • Under the Monte Toc • Longarone (Piave River), Erto, How was it building? Casso • People was it building night-day. • They lived next to the dam was not Who was the builder? ready until. • SADE: 1957-1959 benchmarkes: 1960-1962 • Stay there the people because they wanted to sell the dam. • ENEL: from 1963 responsible THE VALLEY’S PROBLEMS
Some geological works in the territory brought to the identification of some landslides, one of them was extremly dangerous: it was in the left slope, instead in the opposite slope there was a detached piece. The landslide divided the valley into two parts. Some studies confirmed that the landslides could move itself so began some investigations to control the territory.They didn’t understand the true extension of the landslid:it started frome 1200m and not850m of the “Pian della Pozza”. THE WORKS of the VAJONT DAW
The daw was built in a inappropriate area because it was very unstable.The works began in September 1956 and they finsihed in August 1960: in these years the geological knowledge was inappropriate, they studied with superficiality beacuse of the limitated economic sources. The real situtation was found out during the daw construction.The catastrophy could have been avoided if the constructors had listened to the geologists’ observation. Caloi,Muller,Giudici and Semenza forecast the fall of the montuain. THE PROJECT “GRANDE VAJONT” After the Second World War there was an important request of electricity and the idea of building Vajont dam. But this idryelectric plant was supported by other plants located along the river Piave, the river Boite and river Maè. The deviation of the Piave river water flow allowed to build several artificial lakes. These plants were situated in Piave del Comelico, Vodo di Cadore, Valle di Cadore, Pieve di Cadore, one of the towns near the Centro Cadore lake, the famous Vajont dam, in the countryside of Erto and Casso, Pontesei and a plant in the Santa Croce lake. However the Vajont dam contained more than one and a half times the sum of the volumes of water of all the other basins of the system. They are connected by a complicated system of pipes. The result had to be the regular operation of the idryelectric plant during the year even during the less rainy seasons. In this project were used seven electrical stations that they had to distribuite the electricity for common use of the people, producing one-fifth of the electricity Italian. THE PROJECT “GRANDE VAJONT” All systems still function also after the disaster, Vajont dam could no longer work and today the plants is closed. The connections between the plants were modified and was made a new connection system between all plants still in operation. The project “Grande Vajont” is faled because if it had to be an important plant for the national electricity, now it is one of many dam projects of medium size spread throughout Italy. The most important electric station in the project “Grande Vajont” is the Soverzene station, it was build in 1950 and it collects water from all the kisses of the “Grande Vajont” still working electricity to the entire north east. With the failure of the entire project, the Soverzene station has had to reduce the production, so it is decreased the area of distribution of energy. COMMISSION of the VAJONT DAM (1958-1961)
•1957-58: building of the dike adn firsl plans La Piaz and Leopold Muller making benchmarks of the nearby mouintans (Monte Toc) (La Piaz-): various reusltes •1959: First land slide :6.000.000 m³ material -> no disaster, because there were no settlements in the nearby area New benchmarks (Eduardo Senza): new result what forcasted the disaster •1960: First charge of the Vajont dam October: 2.5km long and 1m wide rift has been found on the side Monte Toc Noember 4.: New landslide-> 700.000 m³ material •1961: Carlo Semenza (Builder of the dam) died Secund charge of the dam until 1962 december: 700m high charge
1962 This was a crucial year for the disaster because in 1962 it was approved the nationalization of electricity and so the SADE was forced to sell the hydroelectric plant to ENEL. Obviously the SADE wanted to earn the most possible and so they start to test the daw with a contuinuos elevetions and sags of the level of the water. But this was causing the collapse of the landslide. During this year the university professor of Padua Ghetti will give the results of his experiments, declaring 700 m above the sea level the safety limit. These experiments were not made with the total precision, but the SADE won’t listen to the professor. Despite SADE tried to manage the landslide, none bothered to evacuate the countries that are in danger and this was one of the biggest faults of the SADE 1963 In this year the dam passed from the SADE to ENEL and this contributed to create more confusion in the management of the landslide. and this contributed to create more confusion in the management of the landslide. Engineers tried to find a solution, deciding to drop the landslide with the method of the creeping. So in this year they began to changeconstantly and quickly the water level. In june, when the water level overcame the limit of 700 m, the landslide started to move (0,5 cm per day). Despite this technicians continued to raise the water level, arriving in august at 710m. After that the landslide started to drop faster and so ENEL decided to flare the artificial lake in 26th of september, but it was too late. In 9th november at 10:39 p.m. the landslide began to fall at the speed of 100 km/h with deafening noises and a strong glow. CONSEQUENCIES At 10:39 P.M., a massive landslide of about 260,000,000 cubic metres of forest, earth, and rock fell into the reservoir at up to 100 kilometres per hour completely filling up the narrow reservoir in front of the dam. The landslide was complete in just 45 seconds, much faster than predicted, and the resulting displacement of water caused 50,000,000 cubic metres of water to overtop the dam in a 250-metre high wave. CONSEQUENCIES The wave..
1. Destroyed the village of Longarone, and the villages in the territory of Erto e Casso.
2. Caused the death of 2000 people.
3. Crated a 80 meter wide and 60 meter deep crater.
4. Turned the ground below the dam into a flat plain.