Sheffield Dam

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The Sheffield Dam is a dam in Santa Barbara , California . It was the first dam in the world to fail in an earthquake and is still the only dam in the United States that was destroyed in this way.

The dam is located at the foot of the Santa Ynez Mountains on the northern outskirts of Santa Barbara. It was built on Sycamore Creek in 1917. The dam was designed as a homogeneous earth dam, which was approx. 216 m long and approx. 7.5 m high. At the time of the earthquake, the storage volume was around 113,000 cubic meters.

Dam break

The earthquake had a magnitude of 6.3 on the Richter scale (according to other sources, 6.8) and happened on June 29, 1925 at 6.44 a.m., according to another source on June 28 at 3.27 a.m. The tremors increased the pore water pressure in the soil layer of water-saturated sand and silt on which the dam was founded and caused the soil to liquefy. This phenomenon is called liquefaction ( soil liquefaction ). According to Max Herzog , the dam break can be traced back to block sliding over a partially liquefied subsoil made of water-saturated silt sand.

The dam began to slide on the liquefied subsoil and its middle section slid about 30 m over a width of 90 m. The entire content of the traffic jam spilled into the city between Voluntario and Alisos streets in a tidal wave . The wave carried trees and cars and tore down three houses. In the lower areas, the water was at times up to 60 cm high after the incident. After that, it gradually drained into the sea, leaving behind a mud desert.

Thirteen people were killed in the accident and many more were injured. In the reports, however, it is not mentioned whether they died from the earthquake, for example from collapsing buildings, or drowned in the tidal wave. If they died in the three houses that were swept away, they should also be seen as dam victims.

The dam was rebuilt in 1936, but no longer exists today.

See also

literature

  • Max Herzog : The break of the Sheffield Dam in Santa Barbara during the earthquake on June 29, 1925 in retrospect . In: Österreichische Wasserwirtschaft 44, 1992, ISSN  0029-9588 , pp. 206-208.
  • James L. Sherard, R. Woodward, S. Gizienski, W. Clevenger: Earth and Earth-Rock Dams. Engineering Problems of Design and Construction . Wiley, New York NY et al. 1963, pp. 159ff.

Individual evidence

  1. ↑ Herzog, Max: The rupture of the Sheffield dam in Santa Barbara during the earthquake on June 29, 1925 in retrospect, in: Österreichische Wasserwirtschaft 44 (1992) No. 7/8

Web links

Coordinates: 34 ° 26 '44 "  N , 119 ° 41' 35"  W.