Abstract: In order to improve the ability of disaster prevention and reduction in tailings reservoir downstraeam, taking Beijing Heshangyu tailing reservoir as an example, physical model experiments were carried out to explore effects of dam-break flow's volume fractions, collapse forms and downstream slopes on flow charateristics and regularity of tailing dam-break flow . The experimental results show that with increasing of tailing flow volume fraction, the time that tailing dam-break flow reaches accumulation depth peak is longer and accumulation depth peak is greater. With increasing of collapse gate, the time that tailing dam-break flow reaches accumulation depth peak is shorter and accumulation depth peak is greater. The larger collapse gate of tailing dam-break is, the more widely tailing flow moves in the downstream and the greater coverage area of tailing flow is.With increasing of downstream slope, the time that tailing dam-break flow reaches accumulation depth peak is shorter and accumulation depth peak is smaller. Downstream slope has only a fairly weak effect on the movement process and coverage area of tailing dam-break flow.

Key words: dam-break flow, flow characteristics, flow concentration, collapse form, downstream slope