Dam Failure Case Study: Barahona No. 1 Dam (Chile, 1928)

On December 1, 1928, an 8.2M earthquake struck central Chile. Barahona Dam Nr. 1, located just over 100 miles from the epicenter, survived the quake then failed catastrophically moments after. Four million tons of copper mine tailings were released downstream, killing 54 people and destroying several bridges and a railroad. At the time of failure, the dam was 65 m (~213 ft) high and 1,885 m (6,184 ft) long. The cause of the failure was seismically induced flow liquefaction, resulting from a decrease in the shear strength of the tailings and large displacements of the sand embankments. The dam was repaired and abandoned after the failure. This was the first record of an earthquake induced collapse of a tailings dam in Chile.