1 MIN. DE LECTURA
BELO HORIZONTE, Brazil, Aug 29 (Reuters) - An investigation launched by Brazilian miner Samarco, and its owners Vale SA and BHP Billiton, into the cause of a dam spill last November found the dam collapsed due to liquefaction, a presentation said on Monday.
Liquefaction is a process whereby a solid material such as sand loses strength and stiffness and behaves more like a liquid. Norbert Morgenstern, a geotechnical engineering professor that presented the results, said liquefaction occurred because sand in the tailings dam was "loose, uncompacted and saturated." (Reporting by Marta Nogueira; Editing by Alan Crosby)