Barrage de Fergoug

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Coordinates: 35 ° 31 '18.2 "  N , 0 ° 2' 46.1"  E

Map: Algeria
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Barrage de Fergoug
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Algeria

The Barrage de Fergoug (also Barrage de l'Oued Fergoug or Barrage de l'Habra ) is a dam near Mohammadia (formerly Perrégaux ) in Algeria , Muaskar province , which has been destroyed and rebuilt several times . When the wall broke on December 15, 1881, around 250 people died.

First dam

The first dam wall was built on the river l'Habra between 1865 and 1873. It failed for the first time during construction on March 10, 1872, with no deaths. There was a breach of 55 by 12 m.

After completion, it was a 36 m high and 316 m long gravity dam made of masonry with another wall on the right side and a 125 meter wide overflow. The volume of the reservoir is given in the sources as 30 or 36 million m³. The greatest height above the foundation was 43 m. The designer was the engineer M. Barrelier. The building material was obtained nearby for economic reasons. However, the materials were of poor quality; Among other things, the sandstone was permeable to water and the cement contained floating lime. As a result, the masonry was porous and not watertight. When it was first filled, the water seeped through the wall like a large filter. Nevertheless, the dam wall withstood the loads for eight years.

In December 1881 there was an unusually strong thunderstorm in which precipitation of around 170 mm fell in a short time. The wall was flooded with water at a rate of 850 m³ / s. In all probability, 98 million m³ of water flowed over the top of the wall in one night. The height of the water level above the crown was calculated to be 3.9 m. This overflow alone would not necessarily have caused the wall to slide, but the compressive stresses on the air side became too great due to the inferior building material and the associated inadequate statics. As a result, the wall broke over a length of 125 m, killing between 200 and 250 people; Furthermore, a large number of houses, bridges and railroad tracks were destroyed.

Second dam

The dam was rebuilt from 1883 to 1885 at a cost of 1.3 million francs; the cross-section was changed. The total width was 478 meters. Despite its larger dimensions, the capacity of the reservoir is only estimated at 14 million m³.

This wall collapsed on November 26th, 1927 after about a week of heavy rain. Although the drain valves were opened as much as possible, the water level continued to rise until the wall collapsed over a width of 200 meters. In Perrégaux, among other things, 50 houses and the railway bridge were destroyed. Because 45 minutes beforehand there were warnings about the breach of the dam and the population was able to flee, no people were killed there; outside Perrégaux, however, there were again fatalities.

Third dam

The dam was not rebuilt until 1970. After its completion, the reservoir contained 17 million m³; however, the capacity sank rapidly due to silting and in 1977 was less than 10 million m³.

In 1986 about 10 million m³ of sludge were removed by dredging, which had a significant environmental impact.

Nevertheless, the reservoir continues to silt up, which last led to protests by farmers in 2020 after bottlenecks in the water supply.

See also

literature

  • JD van Buren: Notes on High Masonry Dams . In: Transactions of the American Society of Civil Engineers . tape XXXIV , 1895.
  • Belkacem Mekerta, Abdélaziz Semcha, Fadéla Rahmani, Jean-Pierre Troalen: Erosion spécifique et caractérisation de la résistance au cisaillement des sédiments du barrage de Fergoug . In: Xèmes Journées, Sophia Antipolis . Editions Paralia, 2008, ISBN 978-2-9505787-9-2 , pp. 135–144 , doi : 10.5150 / jngcgc.2008.013-M ( paralia.fr [PDF; accessed April 4, 2021]).

Web links

Individual evidence

  1. ↑ a b c Karim: La construction du barrage débuta en 1865. In: merise18191. December 31, 2007, accessed April 4, 2021 (French).
  2. ↑ Perregaux - Le pays des Oranges. Archived from the original on February 8, 2018 ; accessed on April 4, 2021 (French).
  3. ↑ Karim: La rupture du barrage en 1927. December 31, 2007, accessed on April 4, 2021 (French).
  4. ↑ a b c Belkacem Mekerta, Abdélaziz Semcha, Fadéla Rahmani, Jean-Pierre Troalen: Erosion spécifique et caractérisation de la résistance au cisaillement des sédiments du barrage de Fergoug . In: Xèmes Journées, Sophia Antipolis . Editions Paralia, 2008, ISBN 978-2-9505787-9-2 , pp. 135–144 , doi : 10.5150 / jngcgc.2008.013-M (French, paralia.fr [PDF; accessed April 4, 2021]).
  5. ↑ liberte-algerie.com: Des mesures pour réhabiliter le barrage de Fergoug: Toute l'actualité sur liberte-algerie.com. September 13, 2020, accessed April 4, 2021 (French).